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- Front Matter: Volume 8912
- Low-Light-Level Technology and Applications
Front Matter: Volume 8912
Front Matter: Volume 8912
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings Volume 8912 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.
Low-Light-Level Technology and Applications
Experimental study of all-weather NIR laser active imaging system
Show abstract
An all-weather NIR laser active imaging system with high power NIR pulse laser, image intensifier CCD (ICCD)
camera and range-gated synchronization control technology is developed for acquiring longer detection range and high
resolution image in adverse weather conditions. The system composition and working principle are introduced. The
laboratory and outfield experiments have been done to validate imaging effect and imaging quality. The results show that
the minimum resolution is about 5cm when observing the target far from 1200m in the dark of night and the image
resolution could reach to 10cm when observing the target far from 2500m in misty condition. Furthermore, the minimum
resolution is about 20cm when observing the target far from 4800m and the image is too blurred to accurately identify
the target when observing the target far from 7200m in rainy condition. The system could be widely used in target
reconnaissance, coastal patrol, search and rescue at sea, airports, ports, oil fields and forest fire prevention.
Infrared simulation of 4-bar target for the static performance evaluation of thermal imaging system
Show abstract
In order to evaluate the performance of themal image system, an infrared simulation method of 4-bar
target is put forward based on blackbody radiation characteristics. These simulated targets are efficient
inputs for performance testing and evaluating the minimum resolvable temperature difference and
spatial resolution of the infrared computer simulating system. Finally, the infrared simulation images of
standard 4 bars target, which have tunable spectral band, adjustable temperature difference and
different spatial frequency, are realized by utilizing Matlab.
Analysis of process parameters of micro fluid-jet polishing on the processing effect
Show abstract
Micro fluid-jet polishing technology is a new kind of ultra-smooth machining method which proposed on the basis of
float polishing principle and combined with small tool polishing. This article will use micro jet ultra-smooth machine
which developed by ourselves to develop the process experiment for plane elements. In the experiment, the material
removal rate and surface roughness are taken as the assessment index, and the orthogonal experiment method is used to
study the processing effect of different process parameters, such as the spindle speed, the pressure of the grinding head
and the abrasive concentration. On the basis of the experimental results and combined with the micro jet polishing
mechanism, the processing effect law of the various process parameters is analyzed. It shows that, the influence of
polishing pressure and abrasive concentration on the removal efficiency is single, that is to say, the removal efficiency
can be increased either by increasing the polishing pressure or by increasing the concentration of the slurry. However,
the influence of the grinding speed on removal efficiency is not simple, the removal efficiency can be increased by
increasing the grinding speed in the certain range, if continue to increase, the removal efficiency will decrease. The
influence of the process parameters on the roughness is more complex, but it can be summarized grossly as follows: if
the roughness is required to reduce quickly, the large polishing pressure and high concentration slurry can be chosen,
but it has a large depth of removal; if the roughness is required to reduce and the removal depth is as small as possible,
the little polishing pressure and the dilute polishing liquid can be chosen, but it has a long polishing time. So in the
actual processing, the process parameters should be adjusted according to different machining needs, to finally reach the
optimization.
Research on the jamming mechanism for intense light bomb by antagonizing low-light level night-vision device
Jinxi Che,
Zhongmin Li,
Jinchun Zhang
Show abstract
The low-light level night-vision device was widely applied in military and common field. The working principle
of the low-light level night-vision device and radiation shine mechanism of highlight interference bomb were analysed. The
tactical use way of the highlight interference bomb was briefly analysed. In addition, the computing method of flash radiation
was provided. The jamming mechanism for intense light bomb by antagonizing low-light level night-vision device was analysed
from the relation between surroundings illuminate and luminance of fluorescent screen, the relation between target illuminate and
damage threshold of fluorescent screen and the influence on lifetime of instrument by intense light, which provided reference to
study the jamming technology on the low-light level night-vision device.
Influence of surfactant on aperture of photo-electro-chemical etching for silicon microchannel plate
Show abstract
The influence of several surfactants in electrolyte during silicon electrochemical etching was reported in this paper. The
morphologies of macroporous silicon arrays in n-type silicon are strongly influenced by the chemical nature of these
additives. Conventional solvents (HF-Ethanol) with cationic (hexadecyl trimethyl ammonium chloride), non-ionic
(Triton-X100) and anionic (sodium alpha-olefin sulfonate) surfactants were experimented respectively. Prominent
differences in microchannel morphologies and apertures were observed depending on the nature of the additive. The
different behaviors of the additives during the electrochemical etching process were linked to the physical properties of
the additives. We found the electric double layer model of the reaction interface partially to explain these results.
However, not only the morphology of the microchannel but also the degree of electrochemical reaction is affected by
surfactant. The anionic surfactant is more suitable for the preparation of silicon microchannel plate with high aspect ratio
and pore size uniform. The depth of microchannels etched by photoelectrochemical etching silicon with anionic
surfactant is 264 μm, and the pore size is 2 μm.
Development of thermal infrared imaging system
Show abstract
Development of thermal infrared imaging system has experienced three generations. The main features of every
generation are illustrated briefly. The 3rd thermal imager prototype of the United States is as example. The key
techniques are analyzed in detail, which are adopted in the optical system, infrared detector module, control and signal
processing circuits,etc. The traits of the 3rd Generation thermal imager are summarized. These provide certain critical
thinking to research and development of Chinese 3rd thermal infrared imaging system.
Influences of temperature and etching voltage on the surface morphology of photo-electro-chemical etching for silicon microchannel arrays
Show abstract
The application fields of high aspect ratio Si microchannel arrays have increased considerably, for example, Si
microchannel plates, MEMS devices and so on. By the method of photo-electrochemical etching (PEC), Si microchannel
arrays are prepared using n-Si wafer covered by anti-corrosion layers and initiation array pits. The dark current intensity
curve of an n-type silicon wafer was presented in aqueous HF. The relationship among temperature, etching voltage and
carrier transportation was presented. The influences of temperature and etching voltage on the surface morphology of
silicon microchannel arrays were researched. The perfect Si microchannel arrays structure with the pore depth of 297 μm,
the pore size of 3 μm and the aspect ratio of 99 was obtained by the method of reducing etching voltage gradually.
Effect of ion barrier film on the noise characteristics of proximity focusing low-light-level image intensifier
Show abstract
To analyze the effect of ion barrier film in micro-channel plate on the performance of proximity focusing low-light-level
image intensifier, the noise characteristics of ion barrier film are studied. The transmission electrons’ distribution for
those have transmitted ion barrier films is determined by simulating the collision interaction between the incident
electrons and ion barrier film with Monte Carlo method. Furthermore, the relationship model of the incident electrons
and transmission electrons are established by time differential method. We simulate how the incident electron energy and
ion barrier film thickness affect the noise factor of ion barrier film. The simulation analysis results reveal that the noise
factors gradually decreased with the increase of incident electron energy (0.1 KeV - 2.0 KeV) and decreasing of film
thickness (1 to 8 nm). So the tendency of simulation results is accordant with the actual devices. The smaller noise factor
means the better image quality for low-light-level image device, and the simulation results suggest how to realize the ion
barrier film in low light level image intensifier with low noise factor. Therefore, the study of ion barrier film’s noise
characteristics provides theoretical and technical support for optimization of the
three generations low-light-level device’s performance.
Influences of temperature and concentrations on morphology of TMAH anisotropic etching for silicon microchannel plate
Show abstract
Anisotropic etching of monocrystalline silicon plays an important role in Microsystems technology in the recent
years. TMAH, as one of the anisotropic etchants, is used to fabricate pores with square cross-section. Careful choice of
concentration, isopropyl alcohol additives and temperature of alkaline solution allows for certain crystallographic
directions to be preferentially etched. In this way, pores with square, eight-sided (octagonal) or rotated square shapes can
be attained and convert to each other. We show the etch selectivity on (100) and (110) planes in TMAH solution with
low concentration. The etch rates on (100) and (110) planes at different temperature and concentration has been
measured. The results indicated that the perfect orthogonal array of pores with sharp edges and corners can be obtained
at more than 40℃ in 1wt% TMAH solution. There is good etch selectivity on (110) surface and the etch rate on (110)
surface is slower than (100) surface under the condition.
Several high speed multiplier theory for low-light-level technology
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Low-light-level image intensifier images weak optical signal through electron multiplication process in
Low-light-level night vision device, the key technology of intensifier is electron multiplier, the thesis put forward three
kinds of electron multiplication methods. One is that the electron multiplier device is the avalanche transistor made use
of the semiconductor material, the thesis analyses the photoelectric conversion theory and rapid multiplication avalanche
breakdown conditions with PN junction of the avalanche diode under reverse bias by light excitation; the second
approach is to use gas discharge theory to explains the electron multiplication process in the low-pressure gas and
high-pressure gas discharging breakdown by photon excitation; the third method is photoelectron multiplication gain
theory,in the microchannel plate (MCP) as the second generation image intensifier in vacuum condition and the applied
voltage. The thesis analyses that the electronic gain efficiency is better than the other two methods ,and proposes the
avalanche transistor can be key device of image intensifier.
Method of anti-blooming in measurement of low-light-level television
Show abstract
Blooming is a normal phenomenon in the measurement of low light level television (LLL TV) due to its inner auto-gain
control, which will influence the test result and should be controlled in the measurement process. Analyzing the
blooming principle, a solving method was improved by increasing the ambient illumination on the sense of LLL TV,
which will decrease the auto-gain value of LLL TV. What’s more, this method was validated in an experiment of
resolution measurement of LLL TV by the applying an auxiliary lighting equipment. The auxiliary light equipment was
composed with three ground glasses, twelve LED lamps, and a box brushed with diffuse materials inside. The color
temperature of LED lamps was 3000K whose value is close to the light source (2856K) of resolution measurement.
During the experiment, auxiliary light equipment was placed in front of the LLL TV. By analyzing the output image of
the LLL TV, the blooming phenomenon disappeared and the covered resolution image appeared. The result means that
the method of increasing the ambient illumination on the sense of LLL TV is an effective way to depress the blooming in
measurement of LLL TV, and it can be used to other parameter measurement of LLL TV.
Influence of range-gated intensifiers on underwater imaging system SNR
Show abstract
Range-gated technology has been a hot research field in recent years due to its high effective back scattering eliminating.
As a result, it can enhance the contrast between a target and its background and extent the working distance of the
imaging system. The underwater imaging system is required to have the ability to image in low light level conditions, as
well as the ability to eliminate the back scattering effect, which means that the receiver has to be high-speed external
trigger function, high resolution, high sensitivity, low noise, higher gain dynamic range. When it comes to an intensifier,
the noise characteristics directly restrict the observation effect and range of the imaging system. The background noise
may decrease the image contrast and sharpness, even covering the signal making it impossible to recognize the target. So
it is quite important to investigate the noise characteristics of intensifiers.
SNR is an important parameter reflecting the noise features of a system. Through the use of underwater laser
range-gated imaging prediction model, and according to the linear SNR system theory, the gated imaging noise
performance of the present market adopted super second generation and generation Ⅲ intensifiers were theoretically
analyzed. Based on the active laser underwater range-gated imaging model, the effect to the system by gated intensifiers
and the relationship between the system SNR and MTF were studied. Through theoretical and simulation analysis to the
image intensifier background noise and SNR, the different influence on system SNR by super second generation and
generation Ⅲ ICCD was obtained. Range-gated system SNR formula was put forward, and compared the different effect
influence on the system by using two kind of ICCDs was compared. According to the matlab simulation, a detailed
analysis was carried out theoretically. All the work in this paper lays a theoretical foundation to further eliminating back
scattering effect, improving image SNR, designing and manufacturing higher performance underwater range-gated
imaging systems.
ROIC for HgCdTe e-APD FPA
Show abstract
Ultra-low light imaging and passive/active dual mode imaging require very low noise optical receivers to achieve
detection of fast and weak optical signal. HgCdTe electrons initiated avalanche photodiodes (e-APDs) in linear
multiplication mode is the detector of choice thanks to its high quantum efficiency, high gain at low bias, high bandwidth
and low noise factor. In my work, a passive/active dual mode readout integrated circuit (ROIC) of e-APD focal plane
array (FPA) is designed. Unit cell circuit architecture of ROIC includes a capacitance feedback transimpedance amplifier
(CTIA) as preamplifier of ROIC, a high voltage protection module, a comparator, a Sample-Hold circuit module, and
output driver stage. There is a protection module in every unit cell circuit which can avoid ROIC to be damaged from
avalanche breakdown of some diodes of detector. Conventional 5V CMOS process is applied to implement the high
voltage protection with the small area rather than Laterally Diffused Metal Oxide Semiconductor (LDMOS) in high
voltage BCD process in the limited 100um×100um pitch area. In CTIA module, three integration capacitances are
included in the CTIA module, two of them are switchable to provide different well capacity and noise. Constraints such
as pixel area, stability and power lead us design toward a simple one-stage cascade operational transconductance
amplifier (OTA) as pre-amplifier. High voltage protection module can protect ROIC to be damaged because of
breakdown of some avalanche diodes.
Monte Carlo simulations on particle transmission characteristics of BN ion barrier films
Show abstract
The simulation calculation and analysis on the electron transmittance and ion stopping power for ion barrier films (IBFs)
of BN were performed by Monte Carlo methods. The interaction model between particles and solids were described. We
find the Dead Voltage of BN IBFs is 220V. When the energy of the incident ions is 0.2~0.3KeV, 91%—99% of C+, N+ and O+ are stopped by BN IBFs; while 12%—19% of H+ for BN IBF. The results indicate that BN is an idea candidate for ion barrier films. This work provided a theory support for fabricating high performance low-level-light device.
Development of photocathode and device of near-shortwave infrared extension
Show abstract
HgCdTe and InGaAs material are able to detect near-shortwave infrared extension. The progress of HgCdTe and InGaAs
material and their performances have been discussed. This article mainly presented three aspects of InGaAs negative
electron affinity (NEA) photocathode and image intensifier which are widely used in near-shortwave infrared devices:
the research status, the possible application prospects and the trend.
A fast moving objects detection algorithm based on motion estimation
Show abstract
In this paper, a fast moving objects detection algorithm, based on motions estimation, is proposed. Our algorithm
consists of three main parts: Firstly, we use Enhanced Predictive Zonal Search(EPZS) method to match patches between
video frames, Then, moving objects contour information is extracted by applying Tree Structure Moving Compensation
(TSMC) technique into interesting patch subdivision and matching. Finally, we extract the patches of the target by the
statistics of motion vectors. By applying EPZS we can quickly detect the moving target and get its
information .Experiment shows that the algorithm can quickly and efficiently detected moving target and its contour
from adjacent frames. Compared with other algorithms, this algorithm has better usability and faster processing speed
while not be affected by the moving of camera.
Research on silicon microchannel array oxidation insulation technology and stress issues
Show abstract
Microchannel plate is widely used in the field of low light level night vision, photomultiplier, tubes, X-ray enhancer
and so on. In order to meet the requirement of microchannel plate electron multiplier, we used the method of thermal
oxidation to produce a thin film of silicon dioxide which could play a role in electric insulation. Silicon dioxide film
has a high breakdown voltage, it can satisfy the high breakdown voltage requirements of electron multiplier. We
should find the reasonable parameter values and preparation process in the oxidation so that the thickness and
uniformity of the silicon dioxide layer would meet requirement. This article has been focused on researching and
analyzing of the problem of oxide insulation and thermal stress in the process of production of silicon dioxide film.
In this experiment, dry oxygen and wet oxygen were carried out respectively for 8 hours. The thickness of dry
oxygen silicon dioxide films was 458 nm and wet oxygen silicon dioxide films was 1.4 μm. Under these conditions,
the silicon microchannel is uniformity and neat, meanwhile the insulating layer's breakdown voltage was measured
at 450 V after the wet oxygen oxidation. By using ANSYS finite element software, we analyze the thermal stress,
which came from the microchannel oxygen processes, under the conditions of which ambient temperature was 27 ℃
and porosity was 64%, we simulated the thermal stress in the temperature of 1200 ℃ and 1000 ℃, finally we got the
maximum equivalent thermal stress of 472 MPa and 403 MPa respectively. The higher thermal stress area was
spread over Si-SiO2 interface, by simulate conditions 50% porosity silicon microchannel sample was selected for
simulation analysis at 1100 ℃, we got the maximum equivalent thermal stress of 472 MPa, Thermal stress is the
minimum value of 410 MPa.
Analysis and simulation of remote sensor radiance under dawn-dusk illumination conditions
Haoyang Li,
Pengmei Xu,
Yu Wang
Show abstract
Visible remote sensors generally conduct imaging missions in the morning or afternoon (local time), rarely under
dawn-dusk illumination conditions. As the developing of imaging technology, observation are performed under
dawn-dusk illumination conditions or night-time in use of low light level imaging, which extends operating time of
visible remote sensors substantially.
It is complicated of illumination conditions ranging from full sunlight in day-time to quarter moon in night-time, which
means that remote sensors need large dynamic range. As the reference of sensors designing and ground image processing,
the behavior of remote sensor radiance during satellite running time should be researched for better performance of the
sensors.
The theory of remote sensor radiance simulating was described, and the simulation process was introduced. After the
analysis of simulation results, it is got the features of the change in remote sensors radiance under dawn-dusk
illumination conditions or night-time.
High illumination resolution test of low-light-level image intensifier
Show abstract
High illumination resolution, which directly determines the applied characteristic of night vision system in flashlight or
high light level condition, is an important performance parameter for evaluating the characteristic of low light level
image intensifier used in high light level condition. In this article, according to the limited resolution test technique, the
test principle, test condition and test method to high illumination resolution are described in detail associated with
operation mode and protective way of low light level image intensifier. Test system for measuring the high illumination
resolution has been founded based on the limited resolution test system. The value of high illumination for measuring the
high illumination resolution has been calculated in theory and measured by illuminometer. High illumination resolution
of low light level image intensifiers have been measured in test system, results show that high illumination resolution test
system is satisfied the need for measuring high illumination resolution of low light level image intensifier, and test
system output light illumination must be greater than 1×103 lux. Light of high illumination, which can be correctly
measured by illuminometer, is transferred legitimately. That is worthwhile to evaluate the operational characteristic of
low light level image intensifier.
Characterization study of native oxides on GaAs(100) surface by XPS
Show abstract
In order to know more about the surface state of GaAs(100) epitaxial wafer during a storage period of two years, the
XPS analysis was carried out four times on the surface, respectively polished by chemical etching, stored in desiccator
for half a year, one year and two years. The results indicated that even after cleaned by proper etchant solutions, the fresh
surface was slightly oxidized with Ga2O3, As2O3 and organic contaminant. The epi-wafer was always exposed to air during the storage period, so more and more oxides turned out. The mixed oxide layer comprised of C-OR, COOR, Ga2O3, As2O3 and As2O5 appeared after only half a year. In the ageing process of two years, the oxide types of gallium or arsenic did not change with stable content of Ga2O3 and remarkably fluctuating relative contents of As2O3 and As2O5. Based on the intensity ratio of Ga 3d-Ga2O3 to Ga 3d-GaAs, the thickness of oxide layer was estimated. The oxide layer generated after chemical polishing was very thin, just only 0.435nm thick, and then it grew rapidly, approximately 1.822nm after one year while almost no change any more subsequently. It was indicated that after the epi-wafer was
stored for one year, because of volatile As2O3 or As2O5, there remained a large amount of Ga2O3 in oxide layer, which prevented the reactions between bulk material and oxide layer with oxygen. So native oxide layer plays a role as passive film to protect epi-wafer against the environment during a long storage period.
Study on electron scrubbing methods of Cs2Te ultraviolet double-MCP image intensifiers
Show abstract
Single-MCP Cs2Te solar blind ultraviolet image intensifier couldn’t detect weaker ultraviolet radiation, such as the
ultraviolet radiation near high-voltage wire insulating column. To increase the ultraviolet radiation gain, the double-MCP,
tri-MCP or multi-MCP units are introduced into ultraviolet image intensifiers. In this paper, two pieces of MCP are
cascaded in "V" shape as the electron multiplier of ultraviolet image intensifiers. Processed and scrubbed by the
single-MCP electron scrubbing traditional technology, the desired effect after electron scrubbing still could not be
achieved and flicker phenomenon appeared in field of view. The flicker noise appeared when the image intensifier was
working because the second MCP was not efficiently scrubbed. In order to completely scrub the two pieces of MCP
simultaneously, eliminate the flicker noise, reduce the dark current and achieve a stable MCP gain, the double-MCP
electron scrubbing method should be optimized without changing the assembly process. Combined with MCP
pre-treatment and pre-electron-scrubbing before assembled and scrubbed in “V” shape, flicker noise could be eliminated
effectively, and dark current could be lowered, which could increase the gain and get a clear field of view. Comparing
with two different methods of double-MCP electron scrubbing, either method has its own advantages and disadvantages.
Ultraviolet radiation gain can be increased from 103~104 cd·m-2/W·m-2 to 1.0×105 cd·m-2/W·m-2 by using method of pre-treatment and pre-electron-scrubbing. With prospective ultraviolet radiation gain achieved, double-MCP Cs2Te solar blind ultraviolet image intensifier is manufactured.
Simulations on the electron back-scattering characteristics of ion barrier film
Show abstract
The simulation calculation and analysis of electron back-scattering characteristics for ion barrier films (IBFs) of Al2O3
was performed by Monte Carlo methods. A physical model for the interaction of low-energy electrons with solid was
described. Trajectory and spatial distribution of the electrons were simulated with MATLAB software.The maximum
ratio of the back-scattered electrons was 19% at the incident energy of 0.24 keV. Beyond this value, the number of backscattered
electron decreased slowly with the increase of the incident energy. The back-scattering ratio increased almost
linearly with the increase of IBF density. When the incident energy was 0.7 keV and the film thickness is higher than 7
nm, the electron back-scattering ratio was always ~17% for the Al2O3 IBF. This work provided a theory support for
fabricating high performance low-level-light device.
Measurement conditions study on MCP current gain of the third generation low-light-level image intensifier tube
Show abstract
In order to improve the measurement accuracy of MCP current gain and provide highly reliable feedback to the MCP
production, based on MCP current gain test principle, a device with adjustable incident illumination for measuring the
MCP current gain was established. Under MCP voltage of 800V, 900V, and 1000V, incident illumination of photocathode
varying from 0.1mlx to 8mlx, MCP current gain by this device was measured. According to the curves of current gain,
we knew more about the relationship among MCP current gain, MCP voltage and photocathode incident illumination. It
was indicated that MCP current gain saturation was not obvious with photocathode incident illumination less than 6mlx
and MCP voltage 800V, while with more than 4mlx and 900V, the MCP current gain began to saturate, and with more
than 1mlx and 1000V, the MCP current gain began to saturate. Owing to the characterizations of MCP, the reason why
the MCP current gain decreased was analyzed. With the MCP voltage of the 3rd generation low-light-level image
intensifier tube ranging between 800V and 1000V, the photocathode incident illumination for MCP current gain
measurement should be less than 1mlx. In this study, the determined range of photocathode incident illumination during
MCP current gain measurement and the improved test accuracy of the MCP current gain provides effective reference for
the production procedure of the 3rd generation low-light-level image intensifier tube.
Analysis of first proximity voltage on the property of GEN Ⅲ image intensifier
Show abstract
First proximity voltage is the voltage between the cathode of Low Light Level image intensifier and the input surface of
Micro-channel plate(MCP). There are so many factors influencing the image intensifier performance, and the first
proximity voltage is one of the most important factors that can not be ignored. Based on the theory analysis and test of
different proximity voltage on the gain、signal-to-noise ratio and equivalent background noise, this test has studied on the
important performance of Gen III image intensifier effected by the proximity voltage. By the experimental study, the
increase of first proximity voltage to a certain extent can improve gain、signal-to-noise ratio and equivalent background
noise at the same time. The main cause of this phenomenon is that the increase of proximity voltage can enlarge the
incident electron energy, and then improve the quantum efficiency of the incident electron; meantime, stray electron
produced by field emission at the action of the electric field of filmed-MCP will lead to equivalent background
deterioration. Ultimately we conclude that: 1) Signal to noise is proportional to the square of he cathode sensitivity,
increases with the first collision energy of the incident electron, especially at 200-500ev. 2)In the increasing process of
voltage from 300v to 800v, the gain of filmed-MCP increases rapidly, but lower again when Upk increases further because
of gain self-saturation; lgG and lgUpk are linear relationship, thus the curve can intuitively demonstrate the relationship
between them. 3) Stray electron produced by field emission at the action of the electric field of filmed-MCP will lead to
equivalent background deterioration, but will not exceed the requirements of technical specifications(2.5×10-7lx).
Research on detectable threshold of double MCP ultraviolet image intensifier tube
Show abstract
In order to research the influence of the quantity of the Micro-Channel Plates (MCP) on the detectable threshold
of the ultraviolet image intensifier tube, the wide spectrum image intensifier gain tester produced by Nanjing University
of Science and Technology is employed to test the relation curves between self-made one single MCP ultraviolet image
intensifier tube, two double MCP ultraviolet image intensifier tubes, and photocathode incidence radiation illumination
respectively. With reference to the 3rd-generation low-light image intensifier failure theory, if the radiation gain of the
ultraviolet image intensifier tube is defined as 1,000cd/m2, the tube will lose the effect of image intensification, when
the corresponding photocathode incidence radiation illumination will be the minimum detectable threshold. Viewed
from the test results, the minimum detectable threshold of the single MCP ultraviolet image intensifier tube is 3.0×10-6
W/m2, with the radiance gain linear interval between 3.0×10-6 W/m2 ~4.6×10-5 W/m2; and that of the double MCP ultraviolet image intensifier tubes is 4×10-7 W/m2, with the radiance gain linear interval between 4.0×10-7 W/m2 ~2.0×10-5 W/m2. The test results were analyzed on the basis of the MCP self-saturation effect, concluding that the saturation current density of the single-unit MCP is a fixed , but there may be certain difference among the saturation current density of different MCPs due to different materials and manufacturing processes. The test results show that the maximum of the radiation gain linear interval of the three ultraviolet image intensifier tubes are at the magnitude of 10-5 W/m2, and the non-significant differences also verified the theory. In the double MCP ultraviolet image intensifier tubes, the photocathode-produced photocurrent is multiplied in passing the first MCP and then reaches the second MCP, so the second MCP will reach the state of current saturation earlier than the first MCP, making the minimum detectable threshold of the double MCP ultraviolet image intensifier tubes is lower than that of the single ultraviolet image intensifier tube by one order of magnitude, with the linear gain interval increasing by one magnitude, and the absolute of the corresponding radiation gain of the same radiation illumination within the linear gain interval increasing by 10
times, verifying that the double MCPs can detect much lower and weaker ultraviolet radiation and realize the high gain
theory. The research results has certain guiding effect towards the promotion and application of the double ultraviolet
image intensifier tubes, and has great significance on enhancing the high ultraviolet radiation detection and imaging
technology.
Optical testing of cylindrical surfaces with computer-generated holograms
Show abstract
Increasing demands for highly accurate cylinders require more high-precision testing techniques. The existing
methods of testing cylindrical surfaces can not ensure the highly-accuracy, efficiency, convenience and the overall cost.
In order to acquire highly accurate cylindrical surfaces conveniently at a low cost, a new Fizeau interferometric optical
testing utilizing CGH which is fabricated onto a wedge-shaped substrate is designed. In this test, a slit filter is placed in
the center of the cylindrical curvature to filter out the undesired diffraction orders which occur when the beam hits the
CGH. Meanwhile, the front side of the wedge-shaped substrate is as the reference flat, and the CGH is written onto the
inclined surface, so that the real fringe pattern can not be affected by its reflected beam. Moreover, the design of
cylindrical surfaces under test tilting and off-center relative to the diffraction surface of the CGH results that the required
rays for interference can be obtained effectively from the pinhole filter in the interferometer. Furthermore, high-accuracy
CGH in this test can be processed by conventional microlithography equipments. Corresponding to a cylindrical surface
with 60mm in diameter and f-number of 1/7, the test has been successfully designed and optimized in Zemax whose
testing accuracy is prior to 0.0019λ. Better interference pattern can be obtained because all the other disturbing rays
image outside of aperture in a radius of 2mm. Experiment shows the method is efficient and predominant.
Study of infrared point source simulator for generating the multi-decoy
Show abstract
The hardware-in-loop test system for infrared point-type guide missile was introduced;The
decoy irradiation and motion characteristics were analyzed; multi-decoy generation mode and principle were
studied.
Research of data retention in EEPROM cells
Show abstract
This paper investigates date retention ability of EEPROM cells for a given voltage or temperature by theory and
experiment. The expression of EEPROM date retention is derived. In the temperature acceleration experiment, the
logarithm of device inactivation time have linear ratio with temperature according to Arrhenius formula and the device
life retention was acquired in the various temperature. According to Arrhenius equation, lifetime curve is deduced. In the
electric acceleration experiment, because of the charge leaking on the floating-gate, the threshold voltage would decrease
gradually. In the log-log plot, the decrease efficiency of threshold voltage have linear ratio with time. Under the
assumption that the charge loss mechanism is Fowler-Nordheim tunneling through the thin oxide, date retention time of
EEPROM cells is derived and the experience formula is derived by experiment.
Research on mechanical shock impact of GaAs photocathode photoemission performance
Show abstract
The GaAs photocathode has been widely used in optoelectronic devices such as image intensifiers and
photomultiplier tubes, but it is inevitable for these devices to withstand a variety of mechanical shock. In order to study
the impact on the GaAs photocathode’s photoemission performance caused by mechanical shock, GaAs photocathode
image intensifier is researched in this paper . The spectral response of the GaAs photocathode was tested respectively
before and after several value of mechanical shock(the value of mechanical shock:55g,65g,75g,85g and 95g).The
parameter of the GaAs photocathode can be calculated and the quantum efficiency curve can be fitted as well using the
MATLAB software. The results show that surface escape probability is increased after photocathode is subjected to
mechanical shock, so that its photoemission performance will be improved. We think this phenomenon is due to the
GaAs photocathode surface Cs-O reconstruction. This finding provided a new method to enhance the photoemission
performance of photocathode.
Night vision image fusion for target detection with improved 2D maximum entropy segmentation
Show abstract
Infrared and LLL image are used for night vision target detection. In allusion to the characteristics of night vision
imaging and lack of traditional detection algorithm for segmentation and extraction of targets, we propose a method
of infrared and LLL image fusion for target detection with improved 2D maximum entropy segmentation. Firstly,
two-dimensional histogram was improved by gray level and maximum gray level in weighted area, weights were
selected to calculate the maximum entropy for infrared and LLL image segmentation by using the histogram. Compared
with the traditional maximum entropy segmentation, the algorithm had significant effect in target detection, and the
functions of background suppression and target extraction. And then, the validity of multi-dimensional characteristics
AND operation on the infrared and LLL image feature level fusion for target detection is verified. Experimental results
show that detection algorithm has a relatively good effect and application in target detection and multiple targets
detection in complex background.
Function and its significance of screen luminous efficiency curve
Show abstract
In order to solve the design of screen structure and the compatibility of it with the performance of the
tube, we test the LE of screen in different structure and draw the LE curve. By certain methods of
analysis, we get more information about screen performance. The curve with more information has
great signification, thus it can improve the screen structure and process design. An optimal operating
voltage can be find in the LE curve for each type of structure screen, thus it can match the performance
of the entire tube.
Technology discussion of reducing the equivalent background illumination of Gen Ⅲ Image Intensifier
Show abstract
As the development of Gen III Image Intensifier, photocathode sensitivity, spatial static resolution and
signal-to-noise ratio of the devices are continuously improved except for the view effect. However, for
most devices, the equivalent background illumination (EBI) is excessive, and considerable part is more
than an order of magnitude. Many factors have an effect on the EBI of the Gen III Image Intensifier. By
academic analysis and experiment research, it is demonstrated that: It is the thermal electron emission
of photocathode, dark current, gain of micro-channel plate (MCP) with ion barrier film(IBF), electric
field strength between MCP and photocathode and the light feedback of phosphor that lend to the EBI,
but for the phosphor screen made by the normal process, because of the aluminum film, EBI caused by
the optical feedback is slightly lower, which can not cause the excessive EBI. For the MCP with IBF
after normal processing, even the first focused voltage is added to 350V, the EBI does not exceed the
highest value of 1.66×10-7 allowed by national military standard. Needless to say the photocathode is
the focus factor of the EBI after excluding the phosphor screen, the MCP and other influencing factors.
It is believed that the thermal electron emission of photocathode leads to the excessive EBI. Finally,
without reducing the photocathode sensitivity, by optimizing activation technics, i.e., reduce CsO
quantity, and aging test disposal, the thermal electron emission is weaken, the EBI is becoming lower,
most of the products satisfy with request of technical standard in this index. That is valuable to
accelerate the engineering of Gen III Image Intensifier.
Auto-gated power supply for low-light level image intensifier
Show abstract
The basic principle and formation of the auto-gated power, a new kind power of low-light level image
intensifiers, were described in detail. The advantages and disadvantages of auto-gated power with the
traditional high voltage DC power were studied. The imaging resolution and signal-to-noise ratio were
compared by experiment. Applications of the auto-gated power in military and civil field were
forecasted.
Study on the faint star extraction technology with MEMS gyro aided APS star tracker
Show abstract
Star tracker is the most accurate attitude sensor for satellite. Generally speaking, the higher the
accuracy, the fainter the star can be sensed by the star tracker. How to extract the faint star from a star
image is becoming a critical technology in dynamic condition for star tracker, especially using the APS
(Active Pixels Sensor) detector. A novel APS star tracker with MEMS Gyroscope aided system was
proposed in this paper that could extremely improve the detection effect and capability for the faint
stars. During the exposure time of star tracker, the trajectory of star projection on the detector maybe
occupy more than ten pixels due to the satellite rotation. In this situation, the signal-to-noise ratio will
decline sharply, and the traditional star extraction method for faint star will take no effect. As a result,
the accuracy of star tracker would decline sharply, even more, couldn’t work. Using the MEMS
Gyroscope, the track of star projection can be predicated and measured, on the basis of which the
deconvolution algorithm could be taken to recover the faint star signal. The accuracy of the star
projection centroid could be improved obviously, and the dynamic performance of the star tracker
would be improved by a magnitude. Meanwhile, the MEMS gyroscope has not less volume, mass and
power consumption, which make it more suitable for the application of APS star tracker.
Research on calculation of cathode electron scattering radius in the generation III image intensifier
Show abstract
In the proximity focusing imaging system, the clear degree of images characterized by electronic scattering radius which
could directly decide the resolution. In generation Ⅲ image intensifier, ion barrier film on the input of MCP is a serious
influence factor on device resolution due to its electron scattering process. In this paper the electronic scattering radius
would calculate at the single electron scattering, large electron scattering, and having ion barrier film electron scattering.
Through comparing, it is found that the electron scattering radius is significantly larger at having an ion barrier film on
the input of MCP. The results of calculation show that reducing the gap cathode-MCP and increasing the cathode voltage
could reduce electron scattering radius, so as to improve the resolution of generation Ⅲ image intensifier.
Mechanism analysis of Gen Ⅲ LLL image intensifier GaAs cathode photoelectric emission disability
Show abstract
The focus of the third generation image intensifier photocathode sensitivity decreases in the GaAs are analyzed, and
proposed solutions,experimental results show that the tube microchannel plate(mcp), screen GaAs cathode discharge gas
is caused by decreased sensitivity of the main reasons. Paper used two-layer model, and even negative electron
affinity(NET) interface barrier theory of the photoelectric cathode drop mechanism was discussed , when the
photocathode emission levels of CO adsorption and other harmful gas, chemical adsorption layer of ionic bond formation
will lead to production of cathode surface barrier interfaces. Cathode surface adsorption of the pollutants more ,the
interface barrier becomes thicker, the smaller the electron surface escape probability, when the cathode interface thicker
barrier to the electron surface escape is zero, the cathode photoemission end of life.
Wet etching of AlGaN/GaN photocathode grown by MOCVD
Show abstract
The AlGaN/GaN with thin GaN surface was grown by metalorganic chemical vapor deposition (MOCVD). And one of
two AlGaN/GaN photocathode samples was etched by molten KOH about 40s, and its reflectivity and transmittance are
tested. The thickness of AlGaN and GaN layers are fitted by the matrix formula for thin film optics, and the GaN
thickness of them are 7nm and 2.5nm respectively. And etch speed of GaN are got in molten KOH at about 400°C. Then
the etched and original AlGaN/GaN photocathode samples are activated by Cs/O in the same way. The spectral response
and the result of simulation show that the cut-off wavelength of the etched AlGaN/GaN deviate to the short-wave. And
the quantum efficiency decline with the GaN thickness decrease.
Analysis of the development and the prospects about vehicular infrared night vision system
Show abstract
Through the classification of vehicular infrared night vision system and comparing the
mainstream vehicle infrared night vision products, we summarized the functions of vehicular infrared
night vision system which conclude night vision, defogging , strong-light resistance and biological
recognition. At the same time , the vehicular infrared night vision system’s markets of senior car and fire
protection industry were analyzed。Finally, the conclusion was given that vehicle infrared night vision
system would be used as a safety essential active safety equipment to promote the night vision
photoelectric industry and automobile industry.
InGaAs/InP photocathode grown by solid-source MBE
Show abstract
As an III-V semiconductor material, InxGa1-xAs can response from 0.87μm (GaAs) to 3.5μm (InAs) by tuning the relative amount of Gallium in the alloy. In order to get better the response of the photocathode in near infrared
radiation region (1~1.7μm), InGaAs/InP heterostructure is widely used for photocathode material. The only
composition of In0.53Ga0.47As is lattice matched to the InP substrate and their spectral response is from 0.9μm to 1.6μm. thus In0.53Ga0.47As/InP heterostructure is selected for near infrared response photocathode. The In0.53Ga0.47As layer has been grown on InP substrate used for photocathode by solid source molecular beam epitaxiy (SS-MBE). The photocathode samples were grown to optimize the growth temperature, III/V ratio and growth rate. The In0.53Ga0.47As layer crystalline quality and component were performed by applying high resolution X-ray diffractometer, surface roughness investigations were performed by applying atomic force microscopy. The
Be doping characteristic was checked by the electrochemical capacitance-voltage(ECV). The optical performance of the photocathode is measured by the spectral meter. The collected information is being used to correct and enhance growth characteristics and optimize InGaAs/InP photocathode structure to increase spectral response and quantum efficiency.
Calculation of integral photoluminescence for the GaAs photocathode bonding assembly
Show abstract
The ideal status of the GaAs photocathode bonding assembly is as fellows: the GaAs photocathode should
not have additional stress; the crystal lattice should keep integrity after deposited Si3N4 reflection reducing
coating and bonging process that GaAs epitaxial material on a glass window. In order to estimating the
bonding quality of the GaAs photocathode bonding assembly, integral photoluminescence intensity was
calculated on the ideal bonding condition. Assuming the energy of incident light was absorbed by GaAs
active layer except reflection, according to the optical character of the GaAs photocathode bonding
assembly, the value was calculated. This value could be the standard to assess the quality of the GaAs
photocathode bonding assembly and improve the bonding technology that the GaAs epitaxial material is
bonded to a glass window.
Theoretical study on balanced homodyne detection technique in preparation of squeezed states of light
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We analyze the balanced homodyne detection technique in the detection of squeezed light, which is controlled by dither
locking scheme. We discuss how the balanced homodyne detection efficiency influences the detected degree of
squeezing. Also, fluctuation in the relative phase between the local beam and the squeezed light is discussed, since a little
phase fluctuation would decrease the detected degree of squeezing greatly. Then, the dither locking technique is studied
in detail, which is used to lock the relative phase between the local beam and the squeezed light. The simulation
experiments and theoretically results show that the balanced homodyne detection technique and the dither locking
scheme are efficient methods to get more accurate degree of squeezing in the preparation of the squeezed states of light.
Application status and development trend of infrared imaging system
Show abstract
With the rapid development of infrared imaging technology, it plays a more and more important role in modern wars. In
this paper, the impact of changes of target, environment and mission on the development of infrared detecting
technology was analyzed. Infrared imaging systems applied in army, navy and air force military weapons abroad were
introduced. Meanwhile, the equipment status with infrared imaging technology in domestic situation was present and
compared. In the end, a brief discussion about the development trend on modern infrared system was given. It is useful
for the development and research on the domestic infrared imaging system.
Design for transmissive differential image motion seeing monitor system
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A Transmissive differential image motion monitor (DIMM) optical system is introduced, which
composed of two identical transmissive optical systems. This two transmissive optical system is composed of two
pupil required by DIMM. Compared with traditional reflective DIMM optical system, this new type of DIMM
system has a simple structure, small size, light weight, easy assembly and adjustment, easy to carry, is more
suitable for field work. In order to satisfy the requirement of observation both at daytime and night .we use cut-off
filter in this system to separate the bright sky background from the small stellar target an. Then the system can
work throughout the day and night without interrupt. The spectral bandwidth of the final design is 650nm-880nm,
pupil diameter is 100mm, and focal length is 2300mm, the design result reveals that the image quality is good; the
strehl ratio is above 0.4 after tolerances allocate, which can meet the system requirements. The system can detect
star above 4 magnitude in the day time, which can meet the requirements of the system observation at daytime and
night.
Readout design for 1×64 quantum dot-in-well photodetector array based on wide dynamic range
Show abstract
In this paper, we studied the readout circuit for high sensitivity 1×64 InGaAs/GaAs/AlAs quantum dot-in-well
photodetector array based on wide dynamic range. The improved design capacitor feedback trans-impedance amplifier
(CTIA) is researched as a low-noise adaptive gain control (AGC) CTIA readout circuit. The dynamic range and
sensitivity of the circuit was greatly increased. Two switches K1 and K2 were used to controlling two capacitors 5pF and
9pF, respectively. Then four integration capacitors (1pF, 6pF, 10pF and 15pF) were obtained. The dynamic range of the
circuit was increased 23.5dB. The readout circuit was designed in with the area of 3.6mm×2.9mm in 0.35um CMOS
technology.
A high detection probability method for Gm-APD photon counting laser radar
Show abstract
Since Geiger mode Avalanche Photodiode (GmAPD) device was applied in laser radar system, the performance of
system has been enhanced due to the ultra-high sensitivity of GmAPD, even responding a single photon. However, the
background noise makes ultra-high sensitive GmAPD produce false alarms, which severely impacts on the detection of
laser radar system based on Gm-APD and becomes an urgent problem which needs to be solved. To address this
problem, a few times accumulated two-GmAPDs strategy is proposed in this paper. Finally, an experimental
measurement is made under the background noise in sunny day. The results show a few times accumulated two-
GmAPDs strategy can improve the detection probability and reduce the false alarm probability, and obtain a clear 3D
image of target.
Comparison of resolution characteristics between exponential-doping and uniform-doping GaN photocathodes
Show abstract
The studies of quantum efficiency, electronic energy distribution and stability are highly concerned in the application
of Negative electron affinity (NEA) gallium nitride (GaN) photocathodes while the resolution of photocathodes are
concerned rarely. The resolutions of some image intensifiers are smaller than computational value partly because of
ignoring the resolution of photocathodes. To a certain extent, the resolutions of image intensifiers are influenced by
photocathodes. Electronic transverse diffusion is the main cause of decreasing the resolution of photocathodes whereas
the exponential-doping structure can reduce its influence. In this paper, the resolution characteristics of photocathodes
have been studied by using the modulation transfer function (MTF) method. The MTF expressions of transmission-mode
exponential-doping photocathodes have been obtained by solving the two-dimensional continuity equations. According
to the MTF expressions, the resolution characteristics between exponential-doping and uniform-doping GaN
photocathodes are calculated theoretically and analyzed comparatively. At the same time, the relationships between
resolution and thickness of the emission layer Te, electron diffusion length LD are researched in detail. The calculated results show that, compared with the uniform-doping photocathode, the exponential-doping structure can increase the
resolution of photocathode evidently. The resolution of exponential-doping GaN photocathode is improved distinctly
when the spatial frequency varies from 400 to 800 lp/mm. The MTF characteristics approach gradually when f increases
or decreases. Let f =600 lp/mm, the resolution increases by 20%-48% approximately. The constant built-in electric field
for exponential-doping GaN photocathode can increase the resolution of photocathode. The improvement of resolution is
different from decreasing Te, LD or increasing the recombination velocity of back-interface which are at the cost of reducing the quantum efficiency of photocathode. Therefore, the MTF expressions of transmission-mode
exponential-doping photocathode play a positive role in improving the resolution of ultraviolet detector and optimizing
the structural design of GaN photocathode.
The research of relay lens coupling in image intensified camera
Show abstract
Image Intensified CCD (ICCD) camera is widely used in the field of low-light-level image detection. The crucial part of
ICCD, coupling component, which realizes the image transmitting between the image intensifier and detector, affects the
final performance of the ICCD camera significantly. There are two means of coupling: relay lens and optical fiber taper
(OFT). OFT has the merits of small volume and relatively high coupling efficiency, therefore it is commonly used in the
portable devices or applications with less precision demands. However, relay lens turns out to be a better solution other
than OFT for the applications with no volume and weight restrictions, since it provides higher resolution, perfect image
plane uniformity and manufacture flexibility. In this paper, we discuss a methodology of high performance relay lens
design and based on the method a solid design is proposed. There are three major merits of the lens design. Firstly, the
lens has large object space numerical aperture and thus the coupling efficiency reaches 5% at the magnification of 0.25.
Secondly, the lens is telecentric in both sides of object space and image space, this feature guarantees uniform light
collection over the field of view and uniform light receiving on the detector plane. Finally, the design can be
conveniently optimized to meet the needs of different type of image intensifier. Moreover, the paper presents a prototype
ICCD camera and a series of imaging experiment as well. The experiment results prove the validity of the foregoing
analysis and optical design.
The performance evaluation software for LLL imaging system
Show abstract
To estimate the view range of low light level (LLL) imaging system,
analyze the key factors influencing the system performance, and optimize the system
design parameters, we have established mathematical models for each module
(objective lens, image intensifier, electronic sub-system, displayer, human visual
sub-system), according to the transmission process of signals from the target and
background. Finally, the performance evaluation software for LLL imaging system
has been programmed, with the detection and recognition criterion. The software has
been verified by the field experiment of a specific LLL imaging system, with the
confidence coefficient higher than 80%.
A study on the application of ICCD in low light level remote sensing
Show abstract
Image intensifiers are always used to amplify low light level (LLL) images in a wide wavelength range to observable
levels. As a leader in image intensifiers for industrial and scientific applications, intensified CCD (ICCD) is an
innovative product which is a hybrid of image intensifier and CCD. Over the past few decades ICCDs have been
increasingly developed and widely used in a variety of fields such as LLL television system and medical diagnostics. In
this paper, we present the application of ICCD in the field of LLL remote sensing. General LLL imaging devices are
introduced briefly, and their advantages and disadvantages are compared. ICCD technology which includes fundamental,
configuration and development, is expatiated on. The major parameters which incarnate the performance of the LLL
remote sensing ICCD camera are analyzed in detail, such as signal noise ratio (SNR), dynamic range, spatial resolution,
etc. An ICCD camera is designed, and an imaging experiment is made to validate the imaging ability of it in LLL
condition. The experiment results are discussed and summarized. At last, the most important issues to the application of
ICCD in LLL remote sensing are generalized in detail.
The application of auto-gated power supply in ICCD camera
Show abstract
Intensified CCD (ICCD) imagers have been widely used in low light level imaging system. While the ICCD has
smaller dynamic range in ubiquity, and its output image is prone to saturation in high light level. In this paper, the
auto-gated power supply method is put forward to implementing automatic brightness control (ABC). Consequently, the
ICCD camera imaging dynamic range is improved. Firstly, the principle of the auto-gated power supply is described
briefly, and the design scheme is carried out in detail. The pulse power control mode is adopted to the photocathode
instead of the traditional high voltage DC power supply, and the analog adjustment mode is adopted to the micro
channel plate (MCP). Secondly, an imaging experiment for ICCD camera was made to validate the auto-gated power
supply design, and the experiment results are presented. The results indicated that the design is valid, and the auto-gated
power supply method helps to improve the image quality of the ICCD camera. Finally, the key problems in the design
are analyzed and summarized in detail.
Design of measurement system for low illuminance CCD’s key performance parameters
Show abstract
As an important photovoltaic detector in the night vision imaging systems, some main performance parameters decide
the properties of the low illuminance CCDs greatly including noise, quantum effects, dynamic range and dark current,
and it is necessary to design a measurement system to measure the performance parameters of the low illuminance CCD.
This article designs a set of low illuminance CCD chips’ performance parameter measurement system, which is consisted
of five parts including adjustable monochromatic light source, integrating sphere-darkroom, Dewar control chamber,
main control circuit and the master computer software for automatic measurement. By persistent demonstration, the
performance parameters measurement system which is focused on the low illuminance CCD proposed in this paper has
the advantages of compact, good compatibility, theoretical measurement precision and fully automated measurement
etc.The appropriate equipment and instruments are selected in this measurement system. And the connections of each
subsystem are designed independently, which guarantees the tightness of the total system, eliminate the effects of stray
light at the same time and improves the measurement accuracy of the system. Besides, this measurement system solves
the generation of monochromatic light, and the measurement of low illuminance CCDs at a low temperature.
Study of uniform dot array beam produced by Airy beam
Show abstract
The theory and application of nondiffracting beams is one of the most important
topics in various optical fields. In 1979 Berry and Balazs made an important
observation within the context of quantum mechanics: they theoretically demonstrated
that the Schrodinger equation describing a free particle can exhibit a non-spreading
Airy wave packet solution. After Siviloglou observed Airy beams experimentally in
2007, Airy beams appears as a new member of non-diffracting beams family in very
recent years. In order to explore the potential of Airy beams in the traditional optical
systems, its features and applications are studied. In this paper, we design the
diffractive optical elements to modulate the phase of the beam and produce the
uniform dot array beam based on the Airy beam. We analyze the optical
characteristic of Airy beams and the dot array beam. Numerical simulations
and optical experiments are performed, and the results are in good agreement
with each other. The uniform and the non-diffraction of the modulated beams
are analyzed and the results are promising. It is believed that this study will
provide useful information for further applications and productions of various
Airy beams in optical systems, and it is could be widely applied in operating
and focusing at multi-particles or cells for optical tweezers.