This PDF file contains the front matter associated with SPIE Proceedings Volume 10847, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists.

The relationship between the illumination of the stray light and the modulation transfer function (MTF) of the optical imaging system is deducted by the manuscript. With the analysis, an experiment has been designed to confirm the analysis. The experiment result shows that: the exist of stray light will lead to the optical imaging system MTF reduce, the new imaging MTF is related to the MTF in ideal condition, object contrast, the illumination of the object and stray light.

In order to study the method of optical vortex generation by cascaded spiral phase plates, theoretical analysis, simulations and experimental demonstration of this method are presented. Firstly, theory of optical vortex generation by cascaded spiral phase plates is analyzed. Secondly, an optical vortex generation setup is built, then two experimental groups of optical vortex generation is proposed and generation with single spiral phase plate is set as a control group. On this basis, correlation model is set up, then relative intensity and beam radius with propagation distance are simulated. Simulated graphs of relative intensity and optical radius with propagation distance are plotted and the related rate of change is calculated, initially proving the advantages of cascaded spiral phase plates. Finally, law of relative intensity and optical radius changing of optical vortex with topological charges 5 is studied based on experimental groups and control group, verifying the advantages of optical vortex generation, i.e., law of relative intensity and optical radius changing by cascaded spiral phase plates. By contrast of experimental results, the best configuration of cascaded spiral phase plates is settled.

The use of freeform surfaces is increasing greatly in many fields, such as imaging, aerospace, illumination, biological engineering, and green energy, etc. And the polishing process of these surfaces are usually needed to obtain nanometer scale surface roughness, aiming to implement special functionalities and acquire high added value. This paper introduced the development of the two processes for the polishing of freeform surfaces, one is the serial-parallel hybrid machine based polishing using a self-developed ball-end flexible polishing tool, the other is the multi-jet polishing process. The design was presented in detail, and polishing experiments on plane and freeform surface were successfully implemented. As for multi-jet polishing, the process principle was presented at first. Material removal characteristics were demonstrated through a series of experiments, following with the discussion of application. And the experimental results prove that multi-jet polishing is effective to largely boost the polishing efficiency as compared to normal fluid jet polishing without degrading the surface quality, and also has the potential to extend the application field of fluid jet polishing to medium-large size freeform surfaces.

The thermal effect problem is one of the key research issues in the design of semiconductor laser structures. The heat flow generated in the laser tube has a significant influence on the inherent characteristics of the structure. Thermal modal finite element analysis is an important method to study the influence of thermal load on the intrinsic properties of the structure. It is of great significance for the material selection and structural design of the laser. Based on the mechanical performance and temperature load requirements, this paper aims at the miniaturization of the overall structure. The internal thermal load is analyzed and applied. Based on this, the structure and structural parameters of the semiconductor laser are optimized.

The conventional wavefront reconstruction of the Shack-Hartmann method is based on the measured slopes by using the least-square fitting method. However, this reconstruction method suffers from the low order Zernike terms in wavefront, especially defocus and astigmatism, due to the discrepancy of coordinate systems between the lenslet array and the original wavefront caused by the propagation of subaperture wavefront. In this paper, a ray tracing method was used to calculate the slope error between an input wavefront and the reconstructed wavefront. Then, an iteration procedure including slope compensation and coordination compensation was constructed and implemented to minimize the wavefront reconstruction error. The numerical simulation was performed for a variety of defocus-dominated input wavefront and high-order-dominated input wavefront, and verified that high accuracy wavefront reconstruction can be achieved by the proposed iterative compensation method.

Bonnet polishing has the advantage of high removal efficiency and is widely used in aspheric manufacturing process. However, it is difficult to avoid the mid-spatial-frequency (MSF) error in the process of high efficiency bonnet polishing. Consequently, the paper established the precession simulation model of bonnet polishing, aiming to reveal the effect of precession mode on the surface error, and obtain the optimal precession mode to restrain the MSF error. The three precession modes, i.e., single-step precession, multi-step precession and continuous precession, were compared in simulation analysis and verified through the practical polishing experiments. The experimental results exhibited a good agreement with the theoretical results, which verified the correctness of the proposed model. The results shown that the optimal multi-step precession mode can not only restrain the MSF error, but also obtain better surface roughness. The paper demonstrated the validity of the multi-step precession polishing, which laid the foundation for the high-efficiency and high-precision manufacturing of large-aperture optical components.

Bandpass filters are indispensable to the development of advanced optical and electro-optical systems used in space, defense, and terrestrial applications. In this paper, wideband deep cutoff bandpass filter of 750-900nm was designed and prepared by ion beam sputtering deposition technology. Long wave pass filter with high transmittance from 750 to 900nm and low transmittance from 400 to 730nm was designed and prepared on one side of the HB720 substrate. Short wave pass filter with high transmittance from 750 to 900nm and low transmittance from 930 to 1100nm was designed and prepared on the other side of the HB720 substrate. From the measured transmittance curve, the average transmittance was above 96% from 750nm to 900nm, the transmittance at the wavelength of 728nm and 928nm was less than 0.1%. The results indicated that high quality bandpass filter can be manufactured using the combination method of long-wave and short-wave filters.

CCD camera calibration technique is an important part of image processing. The calibration accuracy of CCD camera parameters determines the precision of the image processing system. With the development of industry, the demand for image processing precision is increasing, so the precision and robustness of CCD camera calibration technique are required to be higher. In order to further improving camera calibration accuracy and simplifying calibration process, in this paper, we proposed a new method of camera calibration on the basis of the traditional camera calibration technique. Different from the traditional calibration method, this new calibration technique uses a “black box system” to build a link between the ideal image points and actual ones instead of setting up linear CCD camera imaging model (i.e. pinhole imaging model) and nonlinear imaging model about camera distortion. The actual pixel coordinates of the camera image are the input values, and the reprojection points obtained by the world coordinates are the output values. In order to verify the validity of this method, we carry out experiments based on the improved calibration method of zhang zhengyou.¹ And finally we verified the feasibility of this method by comparing the experimental results respectively obtained though carrying out the calibration method this paper proposed and the traditional calibration method by camera calibration toolbox.

M3M (Mirror 3 Mirror) of TMT (Thirty Meter Telescope) project is a 3.5m×2.5m×0.1m solid flat elliptical mirror. CIOMP is responsible for the fabrication of M3M as part of China’s share in TMT project. CIOMP have beaning working on this project with TMT Corporation since 2012. The requirement of M3M surface including plate scale (18.8 mas), SlopeRMS (0.8μrad) and roughness (Rq 2.2nm). The testing and fabrication technologies required by M3M are challenges for CIOMP especially 6 years ago. To date, Most of Fabrication and testing technology of M3M have been developed and verified at CIOMP. CIOMP has passed reviews including CoDR, PDR, FRR and TRR successfully with board invited by TMT Corporation. Technologies developed for M3M are including on cite large aperture vertical Fizeau sub-aperture interfere test, scanning pentaprism system, and polishing technology with the goal of minimum slopeRMS. A 1/4 equal-stiffness prototype is also fabricated serving as a pathfinder for the fabrication of M3M. All requirement for M3M are achieved on M3MP successfully. This paper give a brief introduction of the work on M3M, M3MP and some of our results. This work is also supported by Major international cooperation projects of the National Natural Science Foundation.

The effect of environmental temperature upon dark current for seven Satlantic’s OCR504 radiometers was characterized in our laboratory. The resulting dark current was analyzed using three different response models: linear, quadratic and exponential. The results show that a linear model is valid for most bands. However, in some cases, the exponential and quadratic models are more suitable to describe the variations of the dark current.

The defects in the 20 inch PMTs’ glass shell is very harmful for the stress distribution of the whole body and reduce the its lifetime. In this paper, we develop a digital image processing for the detection of 20 inch PMTs’ glass shell, which can detect defects in hollow ellipsoid surface of the PMTs’ glass shell with large aperture. The theory and the final system is showed in this paper, we use a telecentric system with a fixed working distance, a special cylindrical long optic illuminator is placed in the center position of the glass shell, and illuminate the detected surface with uniform intensity light. The image system is placed in a specially made elliptical guideway with the same shape of the glass shell, which is suitable for digital image processing. Finally, by the process of classification and statistics of surface defects ,we can get the result, the defects of the 20 inch PMTs’ glass shell can be examined with a resolution of micron, and the discrimination, classification, accuracy and the detection speed can meet the required indicators.

In order to realize the high efficiency and high focusing coupling and steering of optical waveguide, a variable period focused grating coupler is designed by using the Bragg condition and the Finite Difference Time Domain (FDTD) method. Firstly, the relationship between the structural factors of the grating and the diffraction angle of the coupled light is derived based on the Bragg condition and the plane waveguide eigenmode equation. The effects of etching depth, grating period, duty cycle and other structural factors on the coupled light passing through the grating are obtained. Then, FDTD is used to simulate the diffraction field of uniform grating with different structure parameters. The uniform grating with different structures is combined and the variable period grating coupler are obtained. Finally, the structure parameters of variable-period grating coupler are optimized, and the optimum coupling efficiency and focusing angle are obtained. The coupling efficiency of the optimized variable period grating coupler is 62.37%. It provides a theoretical basis for the practical application of optical interconnection.

One of the important factors that affect the polishing results is the motion modes of the polishing pad in the process of Computer Controlled Optical Surfacing (CCOS). This paper presents a systematic study for the motion modes in CCOS by using a polishing pad. A series of theoretical and experimental studies have been undertaken to investigate the influences of two typical motion modes, called planet motion and orbital motion, on the polished surface, regarding to material removal rate (MRR), middle-spatial-frequency errors, surface roughness, etc. Firstly, the theoretical removal function of the two motion modes was established, and the experiments were carried out by given polishing parameters. A comparison was made between the results of experiments and simulations by the established polishing model. Then, the effects of the mentioned two motion modes on middle-spatial-frequency errors were simulated by the numerical superposition method, and the results were also verified by actual polishing results. Finally, the surface roughness generated by the two different motion modes was examined and compared. The research work shows that the planet motion has higher material removal rate, lower middle-spatial-frequency errors and lower surface roughness, by compared with orbital motion mode, which is helpful for optimizing the polishing strategy during CCOS.

Measurement and compensation of error components are critically important to improve the precision of a measuring system, however, high precision error measurement and separation of rotary axes in the system are difficult for the moving parts. Interferometry is a widely used method to measure errors of axes but can only measure errors at some special location of rotary axes which is not enough to compensate the errors. As a result, this paper proposed a 3-point method based on confocal sensor and optic flat to measure and separate perpendicularity errors with submicron precision, in which the errors at any position of an axis can be measured. Simulation studies based on multi-body kinematics and homogeneous transformation indicate that the six degree-of-freedom errors only have influence on the display of sensors but have no impact on the separation results of perpendicularity errors. Experimental studies were also undertaken. An optic flat with a peak-to-peak value (PV) of 27nm was used as the reference plane of the rotating axis and three confocal sensors with an accuracy of 85nm is used as the measuring sensors. Experimental results show that the proposed method can achieve an accuracy of 5μrad in measuring perpendicularity errors of rotary axes.

Based on the analysis of the demand of low cost, low weight and high reliability of seeker,MEMS gyro is developed to be used in half-strapdown stable platform.For gyro,the dynamic change of bias and scale factor can be caused by the change of internal temperature,external environment and various stre- ss.Accurate output of gyro is crucial to the halfstrapdown stable platform ,a method using an adaptive echo canceller to identify the change of bias and scale factor is discussed,so as to improve the output preci- sion of the gyro and enhance the seeker pointing accuracy.At the end,simulation experiments are performed and the effectiveness of the proposed method is verified.

The fiber optic gyroscope (FOG) has become to one of the most important sensors in developing due to light in quality, high accuracy, compact in dimension and long life. These features have developed new applications of the gyroscope not only in conventional aerospace application area but also in industrial aerospace, such as control and navigations of unmanned vehicles, antenna/camera stabilizers, and so on. Fiber coil is the core of fiber optic gyroscope. The accuracy of fiber optic gyroscope depends on the temperature performance of fiber coil.

In this paper, the temperature transient error model was built based on discrete mathematics model of SHUPE error in the Fiber optic gyroscope and the element physical model of the fiber coil. Based on the temperature distribution model mentioned above, the effects of the coil with different winding method and different geometric dimensions on the temperature performance of FOG were simulated under the same temperature condition. Theoretical analysis and experimental results showed by optimizing the design of the fiber coil, the temperature error of fiber coil can be reduced obviously.

In this paper, a ratiometric wavelength monitor at around 1550 nm based on the passive Silicon-on-Insulator (SOI) integrated device is proposed, theoretically investigated and fabricated. This monitor is made of a single Mach-Zehnder Interferometer (MZI) with direction coupler acting as edge filter. The ouput spectral response is designed to be ‘X-type’. The device shows a resolution of better than 0.4 nm over the wavelength range from 1505 nm to 1585 nm with a discrimination range of 30.5 dB from 15.5 dB to -15dB, which is suitable for wavelength measurement. Based on the single mode principle, the waveguide has a 220 nm×500 nm cross section for TM-polarized mode, and the total chip size is only 18 um×20 um. In conclusion, this proposed ratiometric wavelength monitor based on a single Mach-Zehnder Interferometer on SOI platform can realize the excellent resolution over large wavelength range.

To improve the efficiency of fiber coupling with white LED, According the fiber coupling condition, based on the optical expansion in non-imaging optics theory. Designing two coupled systems of free surface lens and elliptical reflector. Then, the coupled system was simulated and analyzed by LightTools, the results showed that the coupling system of free surface lens has the highest efficiency. Therefore, building the experimental platform of free surface lens coupling system, the results show that the coupling efficiency of fiber coupling system with LED base on Free surface lens as high as 65%. The coupling has the advantages of excellent concentrating efficiency, high coupling efficiency and low cost which can be used for reference to improve the light energy utilization of LED fiber coupling.

The contamination on optical surface is an important factor that causes laser-induced damage. In the assembly process of the SGIII, the traditional manual assembly method poses a great challenge in terms of the cleanliness of optical components. So the contamination introduced by the manual assembly is studied including particulate and non-volatile residue (NVR). The use of vacuum system device to clamp is an important means to achieve automated clean assembly. The contact contamination is the main source of contaminants in the vacuum-clamping process. One source is the organic residue left on the optical surface, by comparing the residue of different sealing rubber after absorbing the optics, we find that FPM (fluorine rubber) brings the least contamination. The second source is the coating debris causing by the compressive and shear stress on the optical surface during the vacuum clamping process. We have established a theoretical model, through the numerical simulation method to obtain the stress under different assembly conditions. For different optical films, the stress during the assembly process cannot exceed the fatigue limit of the optical coating to prevent the film from being destroyed and debris contamination. The cleanliness level of the vacuum clamp assembly process is evaluated through experiments. The results show that the contamination generated by assembling large-aperture optics with a vacuum gripper meets the optical surface cleanliness requirements.

Sand erosion durability of amorphous hydrogenated(a-SiC:H) and non-hydrogenated (a-SiC) Silicon-carbon thin films deposited by direct current(DC) magnetron sputtering on the crystal Silicon have been investigated in this paper. A well calculated simulations indicate that thin film perform processing outstanding sand erosion durability with higher hardness, resulting a promoted processing in the deposition of SiC. The deposition conditions such as gas pressure, sputtering power and substrate bias that all affects the properties of the thin film ultimately, which was tested by Fourier Transform Infrared Spectroscopy(FTIR), Universal Mechanical Tester(UMT) and White Light Interferometer(WLI). The sand erosion test reveals a-SiC thin film has an advantage of mechanical property compared to a SiC:H and DLC coating according to the least impact cracks on its surface, demonstrating the previous calculated simulations strongly.

The thermal stress damage of optical elements always restrict the development of high power laser system. We studied the thermal damage mechanism of the optical elements with contaminants induced by high power continuous wave (CW) lasers. An experiment was carried out by a self-build optical element testing platform and a model based on the temperature field theory and thermodynamic theory was set up. We recorded the thermal stress damage process based on a 10 kW/cm² level mid-infrared continuous wave laser. Then we calculated the thermal damage process of optical elements. The calculated results are in agreement with our experimental record. The results showed the success of modeling calculation in the thermal damage mechanism caused by contaminants.

Near-unstable cavities have been proposed as an enabling technology for future gravitational wave detectors, as their compact structure and large beam spot can reduce the thermal noise floor of the interferometer. These cavities operate close to the edge of geometrical stability, and may be driven into instability via small cavity length perturbations or mirror surface distortions. They are at risk of suffering from problems such as high optical scattering loss and Gaussian mode degeneracy. The well-defined Gaussian beams can also be distorted through their interaction with the small imperfections of the mirror surfaces. These issues have an adverse impact on the detector sensitivity and controllability. In this article an experiment is designed and has been built to investigate the technical hurdles associated with marginally cavities. A near-unstable table-top cavity is built and accurate control achieved through length and alignment control systems. This experiment provides an account of the behavior of the near-unstable cavity. Additionally, the experiment provides an insight into how far cavity parameters can be pushed towards geometrical instability.

Interferometry repeatability is an important indicator for measuring instrumentation and test results. The precondition of improving the detection accuracy is to ensure high-precision repeatability, so high-precision repeatability is one of the most important indicators in precision detection. In the Fizeau interferometer, common light paths are used for the distances from the laser light source to the reference surface, from the reference surface to the detector CCD, and the reference beam and the test beam. However, the strict sense of the co-beam does not exist, and it is not absolute ideal that reference plane has high-precision surface. The test beam reflects from the measured surface will have a certain angular deviation from the reference beam. If so, it may make the reference beam and the test beam reach the CCD detector along different optical paths and generate return error accordingly. And finally it makes effects in sampling and wave surface reproduction. Therefore, using the Zygo GPI system, the 4D system and the H and L system to make research on the same optical platform for relative interferometry repeatability comparison, ensuring that the cavity length is the same, and the standard reference mirror and the tested mirror is the same. Measurements were repeated 50 times for zero-stripes, five-stripes, and ten-stripes. The PV values and RMS values of the 50 measurements make mean processing to reflect the measurement repeatability. Further repeatability error analysis is performed on the phase shift algorithm and PZT phase shifter.

Based on the theoretical removal function model, the internal relation between the fluid dynamic pressure parameters and the processing parameters of the magnetorheological removal function is analyzed. The main technological parameters affecting the removal function are clarified. The single-factor influence experiment was carried out for four technological parameters (liquid flow, concentration of polishing liquid, immersion depth and thickness of ribbon).The relationship curve between the single factor parameter and the removal function volume and the single factor parameter and the removal area is given. The influence of different single-factor parameters on magnetorheological removal function is obtained. The processing of a concave mirror is guided by this rule. High quality optical elements are obtained.

For LED light sources, attaching an optical system for light distribution is of great significance. The uneven illumination intensity at observe plane generated by the LED can’t reach the required degree everywhere. In order to achieve that, can only increase the overall power, which is a waste of resources. This paper designed an optical system to achieve rectangular uniform illumination. The relationship between the coordinates of freeform surface and the coordinate points of the target surface was established, and the differential equations that the free surface should satisfy were deduced, and got its numerical solution. Freeform lens is modeled and ray-traced. After analyzing the simulation results, the optical system basically achieves uniform rectangular lighting effects.

As an excellent optical element material, CaF2 crystal has a wide-spectrum transmission range and stable physicochemical properties. Due to the soft and brittle nature of CaF2 crystal, also with high coefficient of thermal expansion and low heat conductivity coefficient, it is of great significance to study the stability and characterization of the removal function during the processing of large-diameter CaF2 optical elements with specific geometric requirements. In this paper, a Φ200 mm CaF2 crystal plate was taken as the research object. The stable technique of grinding and polishing calcium fluoride is researched and the pressure is treated as the key factor. The specialized tool is designed to control the pressure. The removal model of grinding and polishing is stablished based on the specialized tool. The pressure distribution of grinding and polishing process is simulated and the optimized pressure distribution is obtained. This makes the whole face error converged efficiently and stably, meanwhile the face to face angle can be controlled precisely. As a conclusion, the PV value of experimental element is less than 0.13λ within the aperture, and the face to face angle is restrained into 5″ after using new tools.

A method for measuring the wavefront of wedged focus lens by using the Fizeau interferometer with large aperture and a reflective computer generated hologram (CGH) is proposed. The CGH has 6 zones: one main zone for the null testing of wedged focus lens, one additional zone for alignment the CGH substrate with the interferometer, and four others for the pre-alignment of wedged focus lens by projecting four marks. CGH design process was performed, including the ray trace model for multizone CGH and the optical testing configuration. Simulation results show that the desired precision can be reached with use of CGH and confirm the feasibility of this measurement method.

A polarizer element with subwavelength nanostructured grating was fabricated by using focused iron beam. The gratings on the polarizer are variant spatially. By designing the distribution of the gratings, the polarizer can be used to convert circularly polarized light into radially polarized light. The operation wavelength of the element is 532nm, which has been confirmed by an experiment. Parameters associated with the polarized light converted by the polarizer were also measured in the experiment.

A high-resolution fiber turbidity sensor has been developed to measure the wide dynamic range of turbidity. To improve the accuracy of measurements, the high sensitive single-photon detection technique is adopted in the sensor by using an avalanche photodiode (APD) to detect the total intensity of transmitted light and quantize it to the corresponding number of photons. A theoretical model for turbidity measurement is proposed by combining the B-L transmission law with the single photon counting theory. In order to cover a wide dynamic range measurement based on only one measurement system, an optimal optical power for the sensor must be chosen. Therefore, an experiment is designed to measures the different turbidity solutions by gradually changing the power of incident light. The test results show that, with the increasement of light intensity, the measured data fit better with the theoretical one when the measured turbidity is lower than 0.1NTU. However, the light intensity cannot be increased without limit in high turbidity region, especially when the turbidity is high than 1NTU, since there is a corresponding upper limit for the detection of avalanche photodiode (APD). After the processing and analysis of test data, the test results indicated the sensor can obtain the best measurement accuracy when the optical power of incident light at 11mW. The measured turbidity range is as wide as 50dB from 0.01 to 1000NTU. The proposed fiber sensor is robust and can be used for the wide dynamic turbidity detection for drinking water or some remote monitoring of water pollution.

In recent years, there are a lot of researches about WSNs, but most of them are based on un-weighted networks and the most reality networks are weighted networks. For example, the highway between two big cities in traffic networks is more important than the road links two countrysides. In the evolution process, a new edge weight is established with the probability p according to the triad formation mechanism and with the probability 1-p according to weight priority connection mechanism. The introduction of energy factor balances energy consumption in network, and the triad formation improve the clustering coefficient of the network, and then improve the fault-tolerance of the network. Finally, theoretical results show that the distribution of node weight and the node degree of the network all obey the power-law distribution. Simulation results show that this model has a high clustering coefficient and the good fault tolerance characteristics, and then balance the energy consumption of the network.

Since the performance of binary optical element (BOE) is affected vastly by etching depth error, mask misalignment and feature rounding introduced by the fabrication process, it becomes important to analyze the effects of fabrication errors on the BOE. The phase pattern of binary optical lens will not be symmetrical when the misalignment error exists, and it is very complicate to analyze the diffraction efficiency. Based on the relationship between the diffraction efficiency and the modulation transfer function (MTF), the MTF of a binary optical lens with different fabrication errors is calculated, and the effects on diffraction efficiency are also obtained.

Measurement of the probability density of polarization state need specific phase modulator.However, the existence of mechanic processing error results in the error of the polarization property of modulator. Meanwhile, the error of the measurement system’s alignment is also existing. All of this errors need to calibrate to ensure the accuracy of measurement. In this paper, We present a self-calibration method based on the theory of the probability density of polarization state which is represented in Mueller formalism. After measuring the probability density of polarization state, we can extract the Stokes parameters of a light field of unknown polarization in a single irradiance measurement, by finding the maximum of the probability density of polarization state.

Vortex beams have drawn much attention for their distinct properties. When vortex beams propagate along optical axis, they exhibit complicated physical phenomena. Under tight focusing condition, we investigate the defocusing behavior of two superposed vortex beams with opposite but arbitrary topological charge. The results reveal that the intensity distribution of the focus will be petal-shaped if the two topological charges have opposite sign, where the number of intensity lobes in the focal plane is |m− n + 2| . Meanwhile, we find that the focusing intensity of topological charge m = −n would not appear the helical structure when a defocusing occurs. Otherwise, the defocusing would result in the helical structure of intensity when m ≠ −n , and the rotation of helical structure depends on the sign of m + n . Of which clockwise rotation of defocus intensity is related to the negative m + n , and anti-clockwise direction corresponds to the positive m + n . Furthermore, the helical degree of the helical intensity also depends on the magnitude of m + n . The interesting results obtained in this paper will lead to further advances in the field of optical vortices.

In this paper we will present the development of an integrated freeform optics profile measurement system based on the Phase Measuring Deflectometry (PMD) principle. The developed system can measure freeform optics with an aperture size as large as ~300mm and the slope angle range up to +/-20 degrees. The measurement absolute accuracy is currently around +/-1μm, but it can measure the high order surface profile error with accuracy below 0.1μm. The measurement process is non-contact, quick (the image capturing time less than 1 second), full 3D and easy to setup (no precise alignment required). The whole integrated system is easy to be deployed at the production site.

During the fabricating procedure of optical elements, computer-controlled tools will introduce some periodic structured errors, named mid-spatial frequency errors, which may scatter the laser beams, create filamentous spots or even damage the optical components in Inertial Confinement Fusion (ICF) high power laser system. Transverse translation diverse phase retrieval (TTDPR) is an ingenious phase retrieval method for measuring aspheric and freeform surfaces. In this paper, we explore the measurement of optical elements with mid-spatial frequency errors by using TTDPR. First, we briefly introduce the features of mid-spatial frequency errors and establish the relation between mid-spatial frequency errors and diffraction pattern. Second, with the knowledge of the mid-spatial frequency error, we analyze the feasibility of optical elements with mid-spatial frequency error measurement by using TTDPR. In order to improve the convergence and measurement accuracy of phase retrieval algorithm, initial inputs are optimized for the following iterative phase retrieval algorithm. Results indicate that a 50% higher reconstruction accuracy can be achieved, when the initial input is the ideal lens to recover the phase of lens with mid-spatial frequency errors. For TTDPR, sub-aperture illuminated with overlapping part among adjacent sub-apertures will improve accuracy of iterative phase algorithm than never overlapped sub-aperture, while it encumbers the efficiency of iterative phase retrieval algorithm. Based on the characteristics of the particular optical surfaces, the influence of major parameter of sub-aperture including the size of sub-aperture and the overlapped proportion among adjacent sub-aperture to accuracy and efficiency of TTDPR are also discussed.

With the booming of the curved glass shell and curved panel on the smart phone, the development of 3D curved glass molding process, mold and equipment are fairly promoted. This paper introduces a self-developed full-motor-driving precision molding machine’s developing course. Seven different molding stations using electric actuators as molding axes devices are designed in molding chamber to gives good production efficiency and adaptation of complex process to the molding machine. The maximum molding force and the highest molding temperature is up to 5000N and 800^oC, respectively, which satisfies different production requirements. The control unit is built based on the industrial computer in the console and consists of two parts: numerical control system and temperature control system. The control unit can control the molding speed, depth, time directly while the molding force and temperature are controlled by the mean of feedback system. A 3D curved glass molding experiment is carried out by using the machine and graphite mold and finally the 3D curved glass is produced. This result shows that the precision molding machine has achieved the designed functions to manufacture the 3D curved glass and other different complex optical components.

A project focuses on solving the problem of wavelength measurement of mercury lamps has been established, mainly in the air. Using the Fourier transform method, mercury lamp wavelengths are measured with high-precision, better than 0.1pm. By tracing back to the wavelength of the laser, the measuring device was calibrated very carefully using series frequency stabilized Lasers. The measurement uncertainty is better than 5pm (k=2), in the wavelength range of 250nm to 1100nm.