Proceedings Volume 7514

Photonics and Optoelectronics Meetings (POEM) 2009: Fiber Optic Communication and Sensors

Dieter Stefan Jäger, Hequan Wu, Shuisheng Jian, et al.
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Proceedings Volume 7514

Photonics and Optoelectronics Meetings (POEM) 2009: Fiber Optic Communication and Sensors

Dieter Stefan Jäger, Hequan Wu, Shuisheng Jian, et al.
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 30 October 2009
Contents: 2 Sessions, 54 Papers, 0 Presentations
Conference: Photonics and Optoelectronics Meetings 2009 2009
Volume Number: 7514

Table of Contents

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Table of Contents

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  • Front Matter: Volume 7514
  • Fiber Optic Communication and Sensors
Front Matter: Volume 7514
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Front Matter: Volume 7514
This PDF file contains the front matter associated with SPIE Proceedings Volume 7514, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.
Fiber Optic Communication and Sensors
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A FBG-based, temperature-insensitive vibration sensor
Wenjun Zhou, Xinyong Dong, Lan Li, et al.
In this paper, a novel temperature-insensitive vibration sensor based on a FBG is demonstrated. The FBG is glued in a slanted direction onto the lateral side of a right-angled triangle cantilever beam with an eccentric gear installed on its free end. Vertical vibration applied by the eccentric gear to the cantilever beam leads to a uniform bending along the beam length. As a result, the FBG is chirped and its reflection bandwidth and power change periodically with the variation of the displacement of the free end. The experimental results were compared with the data of vibration measurement of a conventional electrical strain sensor. Furthermore, this sensor is temperature insensitive, owning to the temperatureindependence nature of reflection bandwidth and power of the FBG.
A high sensitivity and large dynamic input range O-E-O optical wavelength converter for hybrid PONs
Lei Deng, De-ming Liu, Min-ming Zhang, et al.
Optical access networks are developing to be large bandwidth, high capacity and long distance. The Hybrid Passive Optical Networks (HPONs) using Time Division Multiplexing (TDM) technology and Wavelength Division Multiplexing (WDM) technology are becoming representative technologies that will be employed in the next generation access network. A novel scheme of HPON system architecture based on the wavelength conversion technology is presented. The advantages and disadvantages of a variety of wavelength conversion technologies are contrastively analyzed, and a novel 1.25Gbps burst-mode Optical-Electrical-Optical Wavelength Converter (BM-OEOWC) used in the uplink channel of this HPON system is realized and designed. The receiver sensitivity of this Optical Wavelength Converter reaches -30dBm, and the dynamic range of the input optical power reaches up to 20dB. Theoretical analysis is presented to explain why Bit Error Rate (BER) would obviously increase if more ONUs are attached to this converter. An improved scheme is proposed at last.
A method of events discriminant in fiber-optic network perimeter protection alarm system
Feng Cao, Deming Liu, Qizhen Sun, et al.
This page introduced the general method of sensing signal analysis in fiber-optic network sensor system, and did a detailed analysis of fiber-optic sensor network signal characteristics which be applied to the perimeter protection alarm system. The author proposed a method of events discrimination with adaptive learning function in the alarm system. After experimental analysis and the practical application, the method can accurately report the abnormal invasion events, and achieve zero false positives.
A novel single-polarization single-mode photonic crystal fiber coupler
Honglei Li, Shuqin Lou, Suchun Feng, et al.
A vectorial finite element method is adopted to investigate this novel single-mode single-polarization (SPSM) photonic crystal fiber coupler which has asymmetric dual-core and two lines of enlarged air holes. we demonstrate that the SPSM region of the designed fiber can be more than 250nm wide for a set of optimized air-hole parameters and show that the width of the SPSM region could change slightly by little adjustment of the large inner air holes. The coupling length between the odd and even x-polarization modes are also investigated through fine-tuning the large and small air-hole diameters.
A ratio method of FCG demodulation on strain measurement
Weilai Li, Miao Gao, Jianjun Pan, et al.
To use FCG (Fiber Chirp Grating) as intensity demodulating sensor, the environmental interference should be eliminated, a method of signal ratio is used. Three FCGs and paired fibers are used in strain measurement, two FCGs are connected in series with the first fiber, one acts as a tensive sensor, the other acts as a compressive sensor. The third FCG is alone connected with the second fiber and acts as a reference. Sensing FCGs' intensity output is divided by reference's. Although the level of interference was put as high as the level of load, the ratio is still of good responsibility with the stress, and is of good linearity, and the maximum error in full range is 1.5%.
An adaptive low complexity and high performance BLAST detection algorithm
Desheng Wang, Jie Fu, Guangxi Zhu, et al.
It is well known that MIMO channel capacity was greatly improved by used of BLAST code, but the existing methods still have the decoding complexity and precision problem. This paper analyzes the advantage and disadvantage of the present detection algorithms for the BLAST system. An adaptive BLAST decoding algorithm with lower decoding complexity is proposed. The simulations show that the adaptive detection can achieve the moderate tradeoff between complexity and performance.
An efficient method for extension of the dynamic input range of burst-mode all-optical wavelength conversion module
Yin-bo Qian, De-ming Liu, Min-ming Zhang, et al.
Hybrid passive optical network (HPON) is one of ideal solutions for the next-gereration PONs with advantages of high capacity, long reach and single transport optical fiber. A novel wavelength division multiplexing (WDM) and time division multiplexing (TDM) hybrid PON architecture based on all-optical wavelength conversion (AOWC) technology is proposed. A novel burst-mode all-optical wavelength conversion module (BM-AOWCM) is developed for the critical system optical power budget, in which an Erbium-doped optical fiber amplifier (EDFA) and a gain-clamped wavelength converter based on a semiconductor optical amplifier (SOA) are employed. The degradation of the bit error ration (BER) of the EDFA and the AOWC are tested, respectively, which would limit the dynamic input power of the BM-AOWCM greatly. Experimental results indicate that the input dynamic range is extended from 5.5dB to 30dB at BER of 10E-9.
Analysis and testing of key technologies of PTN on MAN
Xiancheng Feng, Ying Chen, Wanlong Cui
Broadband connectivity to Internet has quickly become one of the most successful telecom service offerings ever. The meeting and marketplace of the future requires Full-Service Broadband. Full Service Broadband encompasses a unique combination of products and experience that will enable operators and network providers to meet this emerging demand for anywhere access to broadband services, quickly, cost-effectively and with minimal risk. Firstly, the standard of PTN (Packet Transmission Network) are analyzed. Then ,by deep analysis the key technology of PTN on MAN. The key technologies of PTN on MAN can be divided into two group: PBT, PBBREP, RRPP, ERP technology, and Carrier Ethernet with MPLS technology. At the same time, communication each other of MSTP and PTN,T-MPLS and IP/MPLS ,PBT and IP/MPLS are carried out by figures. At last, testing of PTN are analyzed, testing contents mainly include: TDM service function of PTN equipment, long time BER capability of STM-1service, time delay capability of PTN equipment, protection and provisioned backup path function of T-MPLS, Wrapping protection a function of T-MPLS loop network,and OAM functions.
Analysis of mode coupling in the dispersion compensating photonic crystal fiber
Weiguo Chen, Shuqin Lou, Liwen Wang, et al.
The mode coupling in the dispersion compensating dual-core photonic crystal fiber is numerically investigated by the full-vector finite element method (FEM) with transparent boundary condition (TBC). The dependence of the phase-matching wavelength, the confinement loss, the effective mode area and the dispersion on the refractive index of the doped inner core, the diameter of air holes and the pitch is demonstrated. The dispersion value as large as -1426 ps/(nm -km), the effective mode area, 80 μm2 and confinement loss, 1.86×10-6 dB/m at λ=1.55μm are obtained.
Analysis of multiwavelength clock recovery based on Stimulated Brillouin Scattering
Ming Chen, Suchun Feng, Shuisheng Jian
Multiwavelength clock recovery based on Stimulated Brillouin Scattering is realized. The maximum frequency spacing of two channels is theoretical analyzed and experimental demonstrated. The calculated maximum frequency spacing is about 416GHz, and the corresponding wavelength span for multiwavelength clock recovery is 3.4nm. And the total wavelength span for two channels of the clock recovery scheme is demonstrated to be 3.37nm in experiment. Once exceed this span, the clock tones of two channels are out of the Brillouin gain spectrum, and not able to experience the process of SBS. The experiment results are in good agreement with the theoretical analysis.
Compact Mach-Zehnder interferometer based on photonic crystal fiber and its application in switchable multi-wavelength fiber laser
Weiguo Chen, Shuqin Lou, Liwen Wang, et al.
The compact Mach-Zehnder interferometer is proposed by splicing a section of photonic crystal fiber (PCF) and two pieces of single mode fiber (SMF) with the air-holes of PCF intentionally collapsed in the vicinity of the splices. The depedence of the fringe spacing on the length of PCF is investigated. Based on the Mach-Zehnder interferometer as wavelength-selective filter, a switchable dual-wavelength fiber ring laser is demonstrated with a homemade erbiumdoped fiber amplifier (EDFA) as the gain medium at room temperature. By adjusting the states of the polarization controller (PC) appropriately, the laser can be switched among the stable single-and dual -wavelength lasing operations by exploiting polarization hole burning (PHB) effect.
Design and analysis of imagery system of laser scanning
Tianze Li, Zhenhuan Wang, Xia Zhang, et al.
This paper expounds the operation principle of laser scanning imagery system,after analyzing the light source, transmitter,receivewere and the continuous analogue electric signal which are in the laser scanning imagery system,a laser scanning imagery system is designed, the composition and main parts of the system were expounded. The performance referance date were reviewed.The characteristics of this systerm is that it not only can scanned but also can collect reflecting coefficient information and can do laser ranging.This paper analyze and disguess the scanning imagery system and the key technology of laser weapon, finally the applicating prospects of the system are described.
Design and implementation of the broadband network access system over MoCA
Jing Huang, Deming Liu, Guangsheng Wu
In order to provide a high speed scheme for the access of the "last 100 meters", a composite access scheme of EPON and MoCA is proposed in this paper. At the terminal node of FTTX in EPON system, MoCA technique is used to implement broadband data access by distributing network entering household through Coax. A terminal equipment is designed in this scheme, which can receive the optical signal from the OLT of EPON and transform it into RF signal. The end users will receive the RF signal either from the coaxial cable or a RF antenna. This scheme is particularly applicable for FTTB application.There are many advantages in this system, it can provide a reliable room to room, peer to peer full mesh connectivity of digital content among MoCA devices using existing in-home coaxial cables. Plug and play at the majority of serviceable coax outlets in homes with no need to access or change splitters, or run new cables. What's more, it has higher bandwidth and better management. Two group of tests for the EPON+MoCA system were carried out, one for the coaxial cable and one for wireless. The experimental results showed that the average throughput of the system could reach to approximate 100 Mbps which approach to the theoretical throughput of MoCA 1.0 standard. And the transmission throughput had no remarkable change when the RF antenna replaced the coaxial cable.
Optimal design of wavelength converters based on four-wave mixing in photonic crystal fibers with two zero-dispersion wavelengths
Sheng Cui, Deming Liu, Ying Wang
In this paper, we show that the bandwidth of wavelength converters based on four-wave mixing can be considerably broadened if photonic crystal fibers with two zero-dispersion wavelengths are used as the Kerr media. The design method of fiber parametric wavelength converters based on photonic crystal fibers with two zero-dispersion wavelengths is proposed. It is proved that when the input signal wavelength is close to the center of the two zero-dispersion wavelengths, the maximal tuning range of the converted wave can be obtained. And the tuning range is approximately two times the difference of the two zero-dispersion wavelengths, which in turn can selected by tailoring the geometrical parameters of photonic crystal fibers. Numerical simulations show that after such converters can achieve ultra broadband tuning range and high conversion efficiency with much lower pump power and shorter fiber.
Devices of radio over fiber system based on fiber Bragg grating
Li Pei, Chunhui Qi, Tigang Ning, et al.
Nowadays, researches on microwave photonics become more and more important due to the needs for wideband and wireless multimedia. The typical utility system is the radio over/on fiber (ROF ) system. In the past few years, fiber Bragg grating (FBG) has been widely used due to its unique characteristic of wavelength selectivity. Hence, a variety of ROF devices based on FBG have become one of the best programs. In this paper, two kinds of microwave photonic filter are studied, the frequency responses are simulated and the perfect results are gotten. Besides, a method is proposed to realize millimeter-wave sub-carrier generation at central station by using a double-uniform FBG filter scheme. The advantages are analyzed by designing a ROF downlink system, and the eye diagrams in different transmission distance are also analyzed.
Erbium-doped photonic crystal fiber laser
Haili Yang, Shuangchen Ruan, Yongqin Yu, et al.
We have demonstrated a low threshold all fiber laser based on a 9.68 m-long small core Erbium doped photonic crystal fiber (PCF) and also presented results from two separate device experiments. The threshold and maximum output power of the laser are 6.72 mW and 82.6 mW, respectively. Fiber loop mirrors is used as resonator mirrors. The overall system is all-fibered and with low threshold. The PCF we used as gain medium with 9.68 m long, 3.34 μm mode diameter, 0.143 numerical aperture, 1000 ppm doped concentration, 545 dB/km transmission attenuation coefficient to 1310 nm laser. A single-mode diode laser, centered at 980 nm, was used as pump source and the maximum power was 400 mW.
Experimental study of discharge for 200W RF excited slab lasers
Yu Xiao, Juan Liu, Yingxiong Qin, et al.
An 81 MHz TEM electromagnetic wave transmitting between the electrodes would cause the nonuniform discharge along the electrodes. The variation of the voltage distribution with pressure and feed-in power bring difficulties to design match network. In order to achieve impedance matching, in the 2000W RF slab discharge platform the different type of matching network are used. Through analyzing the matching network, the equivalent electrical parameter is estimated. In the experiment, though using resonance inductances the voltage distribution along the electrodes is improved. The results show that under the typical condition of the RF slab laser operation, the matching network can work well and the reflective power is less than 5%. When a mid-feed point is used, the feed-in power is 2000W, two 28nH inductances are attached at both end of the electrodes, two 24nH inductances are fixed on both points of one-fourth of the electrodes, the uniform discharge is got on the 500mm×40mm electrodes, and the feed-in power density is 65W/cm3.
Fabrication of nano-Bragg polymer waveguide by soft-lithography process
Jau-Kun Kuo, Wen-Chung Chang, Kao-Feng Yarn, et al.
A polymer waveguide is successfully fabricated by a new method, which is implemented by a Micro-Electro-Mechanical System (MEMS) process including a stamping transfer technique incorporated with holographic interference, a lithography procedure and soft molding tecnnology. The polymers used in these experiments are OG146 and OG154 with different refractive indices. The near-field measurement for the channel waveguide has shown that the polarization dependent loss is very low. This process is simple, easy and suitable for mass production.
FBG hydrogen sensors based on surface plasmon resonance interaction
Yan Sun, Minghong Yang, Bingbing Wang, et al.
Many different types of fiber optic hydrogen gas sensors have been used to detect hydrogen concentration. Almost invariably these sensors, as well as the electrical hydrogen sensors, use palladium as the gas-sensitive layer by detecting its electrical and optical properties change, when it exposed to hydrogen. However the sensibility of them is poor and the minimum hydrogen detecting level is still very high. Fiber Bragg gratings (FBG) control over the properties of light propagating within the fiber. A change of the effective refractive index of grating period caused by the surrounding environment will cause a shift in the reflective Bragg wavelength. The totally different principle makes FBG with good sensing characters. In addition, FBG has a built-in self-referencing capability and can be multiplexed along a single fiber. Here a new method is put forward to detect the hydrogen concentration by FBG. The working principle of FBG hydrogen sensor is based on surface plasmon resonance. Fiber is firstly side polished in the FBG region to enable evanescent wave interaction. Experiment showed that this method is very sensitive, as low as 0.1% (1000ppm) of hydrogen concentration can be detected and the response time is less then 5 seconds.
Four-element fiber laser hydrophone array
Faxiang Zhang, Wentao Zhang, Fang Li, et al.
A 4-element fiber optic hydrophone array based on distributed feedback fiber lasers (DFB FL) has been developed, constructed and tested. Acoustic sensitivity was enhanced by two diaphragms. The noise floor was tested to be 10-6 pm/√Hz @ 1 kHz and acoustic pressure sensitivity of about 10 nm/MPa was achieved.
Framework of a real-time video monitoring system
Kang Yang, Deming Liu, Min-ming Zhang, et al.
In recent years, most of the monitoring systems are based on digital video recorder (DVR) which records video in a digital format to a disk or other memory medium. These systems are limited in application of small-scale and decentralized local data storage. This paper presents a new kind of video surveillance system based on IP network characterized by large-scale monitoring, user authentication centralized management, distributed services, data transmission through the network for centralized storage. This IP-based real time video surveillance system provides a way to monitor the scene on the spot at any time anywhere.
Influence of underwater 3D imaging precision by water light scattering
Wei Zhang, Kecheng Yang, Min Xia, et al.
In three-dimensional (3-D) imaging measurement, the center location extraction of laser bar is one of the critical techniques in determining the metrical precision of the system. The width and brightness of laser bar varying with the change of detection distance is an important factor which influences on the center location determination of laser bar. The underwater 3-D imaging quality is directly affected by light scattering effect of water. Under coordinate conditions, the width increase and brightness decrease of laser bar brings great impact on the metrical precision of the system. In this paper, the beam spread characteristics of underwater laser transferring procedure is studied and the relationship among the beam spread characteristics of underwater laser transferring, laser beam characteristics and correlative parameters of water is constituted. Finally, based on the existing relationship between beam width and beam characteristics in 3-D imaging measurement, the factors which affect the precision of underwater 3-D measurement are obtained by computing beam spread function of underwater laser transferring under diverse conditions. Calculation result shows that the metrical precision enhances for the improvement of water clarity as well as the reduction of detection distance.
Integrated optical waveguide electric field sensor for lightning electric field measurements
Bao Sun, Fushen Chen
In this work, an integrated optical waveguide electric field sensor with segmented electrodes is designed and fabricated for measurement of lightning impulse electric field. First, the compositions of the sensing system were described briefly. The calibration of the sensor is taken using an impulse high voltage generator and parallel square electrodes. The maximal detectable electric field range (-75 kV/m to 245 kV/m) is obtained by analyzing the results. Finally, the measurements of the lightning impulse electric field are given. As a result, the integrated optical electric field sensor is suitable for lightning electric field measurement investigation.
Nondestructive measurement soluble solids content of apple by portable and online near infrared spectroscopy
Xudong Sun, Hailiang Zhang, Yuanyuan Pan, et al.
Two different near infrared spectrometric systems were used to determine soluble solids content (SSC) of intact apple, including a portable near infrared (NIR) spectrometer and an online NIR system. The pretreatment methods were applied to improve the predictive results. The moving average smoothing was significant. The effective wavelength regions were chosen by interval partial least squares (iPLS) and backward iPLS (Bipls). Then the models were developed by partial least square regression (PLSR) and least square support machine (LS-SVM). Performance comparisons were made in the context of 30 unknown samples prediction. The LS-SVM models were better than others with correlation coefficient (R) and root mean square error of prediction (RMSEP) of (0.88, 0.80ºBrix) and (0.82, 1.01ºBrix) for portable and online measurement mode, respectively. The results demonstrated that the online measurement mode was not as well as the portable.
Numerical simulation and experimental study of self-mixing speckle generated in an erbium-doped fiber ring laser
Daofu Han, Xiuting Zuo, Li Ma
In this paper, self-mixing speckle generated in an erbium-doped fiber laser is numerically simulated and experimentally studied. The experimental model of self-mixing speckle based on an erbium-doped fiber ring (EDFR) laser is presented, and using the theories of light amplification and speckles, the model is theoretically analyzed. With the analytical results, the self-mixing speckle signal is obtained by numerical simulation. The signals represented different velocities are analyzed by fast Fourier transform (FFT), and the result shows that the mean speckle frequency of the signal and the velocity of a dynamic object are linearly related, which is agreed with that of the experimental study. The results of theoretical analysis and experimental study indicate that self-mixing speckle in an erbium-doped optical fiber laser can be used to the measurement of a dynamic object.
Optical generation of microwave signal using FBG-based double-ring fiber laser assisted by saturable absorber
Qizhen Sun, Jian Wang, Deming Liu, et al.
We propose and demonstrate a simple approach to optical generation of microwave signal by exploiting a uniform fiber Bragg gating (FBG) based double-ring laser and a saturable absorber. Parallel arranged uniform FBGs have a wavelength spacing corresponding to the microwave signal. A piece of unpumped polarization-maintaining erbiumdoped fiber (PM-EDF) serves as a saturable absorber, ensuring the dual-wavelength single longitudinal mode operation. Stable dual-wavelength single longitudinal mode lasers are obtained in the experiment. A microwave signal at 28.38 GHz is successfully generated by beating the dual-wavelength single longitudinal mode lasers.
Optical property of BaTiO[sub]3[/sub] ferroelectric film at room temperature
Yonghua Fu, Xiaoqing Zhang, Zhimou Xu
BaTiO3 ferroelectric films were prepared on Si(111) substrate by sol-gel method with glacial acetic acid as solvent, and acetylacetone as stabilizer, barium acetate and tetrabutyl titanate as precursor. The photoluminescence of BaTiO3 ferroelectric films were studied. Intense photoluminescence of amorphous BaTiO3 ferroelectric films excited by blue light was observed at room temperature (RT). The emission band is in a range of 540nm to 660nm in wavelength. The ferroelectric films annealed (at 673K for 8 hours) had the best photoluminescence property, when the films excited by 450nm line, the peak width is about 30nm from 580nm to 610nm, towards the yellow region. Moreover, the photoluminescence of BaTiO3 ferroelectric film is stable. The emitting region, peak wavelengths and width are not dependent on excitation wavelength and/or film thickness. The luminescence intensity increases with film thickness increasing, but decreases with the excitation wavelength raising. The crystalline BT ferroelectric films had no properties above.
Preparation and photoluminescence properties of porous silicon
Zhiwei Chen, Zhimou Xu
There are many preparation methods of porous silicon(PS), such as electrochemical etching(ECE), photochemical etching, chemical etching and so on. ECE, also known as anodic etching, is more common among these methods. A lot of holes are given priority to be etched on the surface of silicon. The top and vertical aspects of the holes are easily etched while horizontal aspects wall of the holes are quiet different, and then tree-like or sponge-like porous structure is formed. In this paper, we obtained porous structure on the surface of silicon using lithography and dry etching method. The diameter of the hole was 2μm or 6μm. The etching depth of the samples was about 70nm, 140nm and 260nm. Photoluminescence (PL) phenomenon was observed by using light of 270nm, 280nm, 330nm, 455nm and 460nm wavelength to excite the samples. The results showed that PL intensity was the best when excitation wavelength was 270nm or 280nm, compared with 330nm, 455nm and 460nm. From PL analysis of all samples, It exists three emission peaks about at 372nm, 425nm and 473nm. When the diameter of the PS was the same, it was found that PS with etching depth at 140nm was more efficient. It means that PL intensity of the was better than other samples when the etching depth was 140nm. Likewise, samples of which the diameter was 2μm has much better PL than that of the other samples.
Propagation characteristics of pico-second chirped soliton in dispersion-flatted fibers with convex dispersion profile
Xin Li, Hongjun Zheng, Shanliang Liu, et al.
The propagation characteristics of pico-second chirped soliton are numerically investigated in anomalous dispersion dispersion-flatted fibers (DFF) with convex dispersion profile (CV-DFF) by use of the split-step Fourier method (SSFM). It is found that higher-order dispersions (β36) can be neglected during soliton propagation in the CV-DFF. The fiber parameters D0 and k2 of the CV-DFF can be controlled according to the practical applications. The spectral width, temporal full width of half maximum (FWHM), and the peak of temporal waveform oscillate with the propagation distance. The period and amplitude of the oscillation increase with the increase of |C|.
Proposal of a Star-16QAM system based on Intersymbol Interference (ISI) suppression and coherent detection
Liang Zhang, Xiaofeng Hu, Tao Wang, et al.
We propose a 40Gbit/s star-16QAM(to define) system based on ISI(to define)-suppression technology and coherent detection. ISI-free BPSK optical signals generated by Mach-Zehnder modulators (MZM) and continuous wave (CW) lights are used to realize a star-16QAM signal. As a result, the obtained star-16QAM signal is also ISI-free. It turns out that the proposed ISI free star-16QAM has better performance in terms of eye opening and constellation diagram comparing with two conventional star-16QAM signals transmitted through 80-km standard single-mode fiber (SSMF) and detected by a coherent receiver.
Research and implementation of the burst-mode optical signal bit-error test
Qiu-yuan Huang, Wei Shi
On the basis of the characteristic of TDMA uplink optical signal of PON system, this article puts forward a method of high-speed optical burst bit-error rate testing based on FPGA. The article proposes a new method of generating the burst signal pattern include user-defined pattern and pseudo-random pattern, realizes the slip synchronization, self-synchronization of error detection using data decomposition technique and the traditional irrigation code synchronization technology, completes high-speed burst signal clock synchronization using the rapid synchronization technology of phase-locked loop delay in the external circuit and finishes the bit-error rate test of high-speed burst optical signal.
Research of application mode for FTTX technology
Zhong Wang, Xiang Yun
With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN, WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. In this paper, technique theory of EPON is introduced at first. At the same time, MAC frame structure, automatic detection and ranging of MPCP, DBA,and multi-LLID of EPON is analyzed. Then, service development ability, cost advantage and maintenance superiority based on EPON technology are carried out. At last,with Cost comparison between FTTH / FTTB building model and the traditional model, FTTB + LAN mode which is suitable for the newadding residential users in general areas and FTTN + DSL mode which is suitable for the old city and rural access network transformation are built up in detail. And FTTN + DSL project of rural information in rural areas and FTTH broadband HOUSE project on service solutions program are analyzed. comparing to the traditional access technologies, EPON technology has the obvious advantages, such as distance transmission, high or wide band, saving line resources, service abilities, etc. These are the qualities which not only be served for home users, but solve more access problems for us effectively.
Research on non-linearity correction of 2D-PSD
Xiawei Zheng, Sihai Chen, Wei Chen, et al.
PSD(Position Sensitive Detector) is a kind of electrophotonic detector based on lateral photoeffect. PSD is widely used in non-contact measurement as it's highly sensitive to the position of incident light. But, it suffers from non-linearity because of nonuniform surface resistance which reduces the measuring precision and reliability. In this paper, The non-linear error of 2D-PSD(Two-dimensional PSD) is partly corrected using algorithm for duo-linear interpolation based on LabVIEW(Laboratory Virtual Instrument Engineering Workbench). The corrected result shows that the linearity of 2D-PSD is greatly improved without increasing the complexity of hardware. After the non-linearity correction, the usable area of PSD is extended and the precision of the measurement system is improved.
Research on the key technology and application of the packet transmission network
Xiang Yun, Zhong Wang
In proportion to the rapid development of telecommunication service, Telecom Operators already have made a strategic transition from "Network, Communication Operators" into "integrated information service provider" to provide customer with varied information service, such as the BT "21st century plan", "Next" plan proposed by France Telecom, FNE and BMS plan by Australia Telstra, RANE Programs by NTT. Domestic Carries also made strategic transition plans. And the priority of network transition is to find the way to build a unified and integrated network supporting carrier-grade Ethernet service also compatible with the conventional network service. The division of the service results in the Packet transmission, namely packet technology, makes Packet-based Transmission Network keeping the virtues of transmission network. The virtues are good scalability, varied operation and maintenance, high-speed protection switching, connection-oriented feature, and building up connection with NMS. At the same time, it adds some characteristics to adapt the statistical multiplexing in the packet service, for instance: connection-oriented label switching, QoS mechanism, dynamic and flexible control plane. The Packet Transmission Network (PTN) can be divided into four layers: packet transmission channel layer (PTC), packet transmission path layer (PTP), and optional packet transmission section Layer (PTS) and physical layer. The key technologies of PTN are as follows: the connection-oriented based label transmission and the statistical multiplexing on packet switching. The use of layer and sub-domain is to provide good scalability. Supporting for fault detection and performance testing and other Operation, Management and Maintenance (OAM) function, linear protection switching, ring protection, dynamics survival technology of pre-placed re-route, QoS, circuit emulation for TDM service, ATM based on PWE3 technique, and MAC layer or physical layer based packet clock synchronization. The application PTN could be convergence of packet service in MAN, such ads DSLAM backhauling, wireless Backhauling and so on. PTN can also take replace the core router in the core network to carry out the high efficient transmission of packet service.
Research on theory and technology for improving optical receiver efficiency in turbulent atmosphere
Rui Bie, Xiuhua Yuan
FSO has some significant advantages such as bandwidths, high-data-rate of transfer and less mass, power and volume, and no regulatory restrictions for using frequencies and bandwidths. Atmospheric turbulence is an important factor that constrains the performance of FSO; most of researchers have always been in search of methods to solve this problem. In recent years, the principle and technology of adaptive optics (AO) have been applied to eliminate the influences of turbulent atmosphere. But for a long time, efforts in the traditional AO methods focus on compensating the turbulence on the pupil plane of imaging system, ignoring the differences between the imaging system and FSO. This paper presents a novel space optical receiver that adjusts the wavefront in the rear focal plane of a lens. It is different from common AO technology that system takes the maximum light energy coupled into a fiber as the estimate parameter for reconfiguration wavefront, according to demands for FSO, and realizes a high-speed wavefront compensation receiver without wavefront sensor. Based on these theories, some simulation analysis is implemented and results are compared with traditional AO, it shows that our technique has the better performances than that of general AO. Finally, the farther work and potential application on FSO are discussed in this paper.
Reverse design of the SMF-PCF F-P cavity
Liwen Wang, Shuqin Lou, Weiguo Chen, et al.
In this paper, we report a new F-P cavity based on single mode fiber and multimode PCF. The PCF has been analyzed by the digital image processing and the FEM in order to obtain its effective refractive index and propagation constants. Then optical characteristics of the F-P cavity based on this PCF are numerical analyzed which provide a theoretical basis for the reverse design of the SMF-PCF F-P Cavity. The practice of fabricating SMF-PCF cavity based on this theory has been carried out and the experimental results and theoretical results were consistent.
Semiconductor quantum wells: old technology or new device functionalities
R. M. Kolbas, Y. C. Lo, K. Y. Hsieh, et al.
The introduction of semiconductor quantum wells in the 1970s created a revolution in optoelectronic devices. A large fraction of today's lasers and light emitting diodes are based on quantum wells. It has been more than 30 years but novel ideas and new device functions have recently been demonstrated using quantum well heterostructures. This paper provides a brief overview of the subject and then focuses on the physics of quantum wells that the lead author believes holds the key to new device functionalities. The data and figures contained within are not new. They have been assembled from 30 years of work. They are presented to convey the story of why quantum wells continue to fuel the engine that drives the semiconductor optoelectronic business. My apologies in advance to my students and co-workers that contributed so much that could not be covered in such a short manuscript. The explanations provided are based on the simplest models possible rather than the very sophisticated mathematical models that have evolved over many years. The intended readers are those involved with semiconductor optoelectronic devices and are interested in new device possibilities.
Strain and temperature discrimination by using a birefringence fiber loop and a long period grating in a photonic crystal fiber
Chun-Liu Zhao, Jiarong Zhao, Wei Jin, et al.
We present a new design for simultaneous strain and temperature discrimination using a high-birefringence fiber loop mirror (HiBi-FLM) concatenated with a temperature insensitive long-period grating (LPG) written in a photonic crystal fiber (PCF). The FLM acts as a sensor head, while the LPG in PCF serves as a filter to convert wavelength variation to optical power change. By measuring the wavelength variation and the power difference of two near peaks in the spectral response of this configuration, strain and temperature discrimination is obtained.
Switchable single-longitudinal-mode dual-wavelength erbium-doped fiber laser based on one polarization-maintaining fiber Bragg grating incorporating saturable absorber
Suchun Feng, Ou Xu, Shaohua Lu, et al.
Switchable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber laser at room temperature is demonstrated. One fiber Bragg grating (FBG) directly written in a polarization-maintaining and photosensitive erbiumdoped fiber (PMPEDF) as the wavelength-selective component is used in a linear laser cavity. Due to the polarization hole burning (PHB) enhanced by the polarization-maintaining fiber Bragg grating (PMFBG), the laser can be designed to operate in stable dual-wavelength or wavelength-switching modes with a wavelength spacing of 0.202 nm by adjusting a polarization controller (PC). The stable SLM operation is guaranteed by a saturable absorber (SA). The optical signal-tonoise ratio (OSNR) of the laser is over 40 dB. The amplitude variation in nearly one and half an hour is less than 0.5 dB for both wavelengths.
Technique analysis of T-MPLS OAM and MPLS-TP OAM
Xiang Yun, Zhong Wang
OAM plays an important role in PTN technology. The main function of OAM is check defect before abnormal event. The bit errors which could be corrected or time deviation could be isolated within a certain range. It dose not disturb network operation. And therefore, it ensure carrier to fulfill QoS commitment and reach SLA subscription.T-MPLS is connection-oriented packet transport technology. Connection-oriented means it can provide carrier-level service and must have equal OAM (Operation, Administration and Maintenance) function of traditional transport network. OAM mechanism becomes key technology of T-MPLS. OAM function is very important to telecom network. It's especially import to network which has QoS. OAM could simplify network operation, check network performance and reduce operation cost. Firstly, the functional requirements of T-MPLS OAM and MPLS-TP OAM are analyzed. The similarity of T-MPLS OAM and MPLS-TP OAM is founded. By deep analysis the mechanism of T-MPLS OAM, it shows that the OAM is import for PTN. Then OAM technique of T-MPLS and MPLS-TP is analyzed in detail. At last, analysis of commonality is carried out on function types. Domain reference model and nesting-technique shows the consistency of both OAM functions. Both of T-MPLS and MPLS-TP introduce OAM nesting. Eight MEG Levels (from 0 to 7) are available to accommodate different network deployment scenarios. In order to distinguish OAM packets of nested MEGs, each MEP tunnels incoming OAM packets by incrementing the MEL in the source direction and decrementing it in the sink direction. Each MEP/MIP generates and processes OAM packets at the MEL=0, while other OAM packets are forwarded with traffic. It's very simple and high efficiency method. By comparing the functions of T-MPLS OAM and MPLS-TP OAM, even there are few differences on PTN implementation detail; the OAM mechanism and framework are basically same. Both of them meet the requirements of carrier-grade OAM. They has important role in their realization process. As long as posses powerful OAM capability, PTN has more competitiveness in the future market.
Temperature-independent fiber Bragg grating acceleration sensor
Lan Li, Wenjun Zhou
An acceleration sensor based on measurement of the reflection bandwidth of a single fiber Bragg grating (FBG) is presented. The FBG is glued in a slanted direction onto the lateral surface at the center of the beam. Two weights were fixed respectively on the upper and lower surfaces in the middle of the beam to sense the variation of the acceleration in the vertical direction. Preliminary experimental results indicate that when the acceleration was increased, the 3-dB bandwidth of the FBG responded linearly from zero to 8 g, with very low temperature dependence. The measurement sensitivity and resolution are 0.4 nm/g and 0.05 g, respectively.
Testing and reference model analysis of FTTH system
Xiancheng Feng, Wanlong Cui, Ying Chen
With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN , WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network.. Fiber to the Home (FTTH) will be the goal of telecommunications cable broadband access. In accordance with the development trend of telecommunication services, to enhance the capacity of integrated access network, to achieve triple-play (voice, data, image), based on the existing optical Fiber to the curb (FTTC), Fiber To The Zone (FTTZ), Fiber to the Building (FTTB) user optical cable network, the optical fiber can extend to the FTTH system of end-user by using EPON technology. The article first introduced the basic components of FTTH system; and then explain the reference model and reference point for testing of the FTTH system; Finally, by testing connection diagram, the testing process, expected results, primarily analyze SNI Interface Testing, PON interface testing, Ethernet performance testing, UNI interface testing, Ethernet functional testing, PON functional testing, equipment functional testing, telephone functional testing, operational support capability testing and so on testing of FTTH system. ...
The comparison of two methods to manufacture fused biconical tapered optical fiber coupler
Yue Wang, Hairong Liu
Optical fiber coupler is a directional coupler which is crucial component for optical fiber communication systems. The fused biconical taper is the most important method in facture of optical fiber coupler, with many advantages of low excess loss, precise coupling ratio, good consistency and stability. In this paper we have introduced a new method to manufacture optical fiber coupler. And more over the new manufacture process has been compared with the traditional manufacture method. In the traditional crafts, two optical fibers are parallel placed, and then use the method of tie a knot of the two optical fibers. In the new process, a new program of fiber placement is introduced. Two optical fibers are parallel placed in the middle of the fixture, and then in order to make the bare part of the optical fiber close as much as possible, the new plan using high temperature resistant material bind the both end of the fiber which are not removing the cladding. After many contrast tests, we can see that adopt the improved method of fiber placement, during the process of fiber pulling, the variation of optical power in the directional arm and the coupler arm are more smooth and steady. But the excess loss (EL) generated in the process of pulling is a bit higher than the traditional method of tie a knot. The tests show that the new method of optical fiber placement is feasible in the actual projects for the manufacture of coupler with low coupling ratio, but for the control of the EL still need further studying.
The influence of adhesive on fiber Bragg grating strain sensor
Jixuan Chen, Huaping Gong, Shangzhong Jin, et al.
A fiber Bragg grating (FBG) sensor was fixed on the uniform strength beam with three adhesives, which were modified acrylate, glass glue and epoxy resin. The influence of adhesive on FBG strain sensor was investigated. The strain of FBG sensor was varied by loading weight to the uniform strength beam. The wavelength shift of the FBG sensor fixed by the three kinds of adhesive were measured with different weight at the temperatures 0°C, 10°C, 20°C, 30°C, 40°C. The linearity, sensitivity and their stability at different temperature of FBG sensor which fixed by every kind of adhesives were analyzed. The results show that, the FBG sensor fixed by the modified acrylate has a high linearity, and the linear correlation coefficient is 0.9996. It also has a high sensitivity which is 0.251nm/kg. The linearity and the sensitivity of the FBG sensor have a high stability at different temperatures. The FBG sensor fixed by the glass glue also has a high linearity, and the linear correlation coefficient is 0.9986, but it has a low sensitivity which is only 0.041nm/kg. The linearity and the sensitivity of the FBG sensor fixed by the glass glue have a high stability at different temperatures. When the FBG sensor is fixed by epoxy resin, the sensitivity and linearity is affected significantly by the temperature. When the temperature changes from 0°C to 40°C, the sensitivity decreases from 0.302nm/kg to 0.058nm/kg, and the linear correlation coefficient decreases from 0.9999 to 0.9961.
The integrated impact of the combination of PMD and several nonlinear effects on 160G bit/s DWDM systems
Wang Yu, Ouyang Zibo
With the help of modern 40Gb/s technology and the AON technology,160Gb/s DWDM optics communication system will be realized in the next few years. However, With broader spectrum, the signal suffers more from chromatic dispersion, optical fiber nonlinear effects ,such as FWM and XPM, as well as PMD.The combination of PMD and nonlinear effects results in more complexity. In this paper, based on nonlinear Schrödinger r equations, from where GVD, TOD, SPM, XPM, FWM and PMD synthetically derived, we investigate the system degradation induced by PMD and nonlinear effects via numerical simulation. The results show that when the signal power is low, PMD has more affection on system comparing with nonlinear effects, when signal power gets larger, nonlinear effects become dominating, but PMD may mitigate their impact to some degree. PMD is becoming major system impairment in high speed and long distance optical fiber transmission systems, we can use PMD compensation module such as a compact variable differential group delay (DGD) element base on concatenation via six magneto-optic polarization rotators (Faraday rotators) .We also study the impact of PMD to high speed optical fiber communication system with different modulation formats ,we get the conclusion that in the high speed and capacity optics system, RZ and SINE PULSE is often used in high transmitting power and low transmitting power, respectively.
The key technique analysis and function configuration of MPLS OAM
Xiancheng Feng, Zhonggong Hu, Ying Chen
OAM function is very important to telecommunication network. Especially to the networks that need to supply QoS, OAM could simplify network operation, check network performance and decrease network operation cost. As the important and extensible carrier technology of next generation network, OAM enables that MPLS could supply multiple services capability with QoS. In this paper, MPLS OAM technique theory and protection are introduced at first. In the introduction, 1:1 protection and 1:1 protection are analyzed; Then, the MPLS OAM key technique is analyzed; At last, it configures the MPLS OAM protection and checks static LSP connection in detail. So, MPLS OAM will be very important to telecommunication of IP-packeted network.
The method for recovering the soft information in the protocol stacks in type of WIFI and WIMAX
Yi Tian, Michel Kieffer, Deming Liu
The paper will present the method for recovering the soft information in the protocol stacks in type of WIFI and WIMAX, which is based on the joint source-channel decoding (JSCD) techniques with enhanced permeable layer mechanism used for wireless multimedia transmission. Packet header recovery at varieties of protocol layers using MAP estimation is the cornerstone of the proposed method. The inherently obtainable correlation of intro-layer and inter-layer header proves to be effective in picking out a simplified set of header configurations for further processing. The best candidate is then obtained using the soft decoding of CRC or Checksum protected data and CRC or Checksum redundancy itself. Finally, with a simulating program written by C++, we can prove that a multimedia transmission system added an AWGN channel (Gaussian noise of zero mean and variance s 2 ) using the method proposed in the paper can really obtain a significant improvement of ENR at the receiver, and effective make the band of transmission much wider and the quality of transmission much better.
Theoretical and experimental investigation of multi-wavelength fiber laser
Jianghai Wo, Qizhen Sun
In this paper, a method for realizing a stable multi-wavelength EDFL at room temperature is analyzed theoretically and obtained experimentally. We have proposed a multi-wavelength fiber ring cavity laser by using EDF as the gain medium. A F-P and a band-pass filter are inserted into the cavity to achieve the selection of multi-wavelength. Meanwhile, by inserting a nonlinear optical loop mirror (NOLM) in the linear cavity, which can suppresses the mode competition owing to the homogeneous broaden line in EDF and eliminates the unstable single wavelength lasing, stable output can be obtained at room temperature. As a result, power-stable, broad bandwidth and uniform multi-wavelength operations with narrow line-width and high side mode suppression ratio are obtained at room temperature. In addition, we also demonstrate a kind of tunable multi-wavelength EDFL based on multi-channel FBG (M-FBG). Four-wavelength output with the flatness and SNR of almost 1dB and more than 50dB is achieved and the output wavelength can be changed by applying stress on the M-FBG.
Theoretical investigation on frequency chirp of gain-clamped wavelength converter
Changjian Ke, Bing Zhao, Deming Liu
A novel semiconductor optical wavelength converter based on gain-clamping structure is proposed. It consists of paired fiber Bragg gratings and tilted-waveguide SOA chip. And inverted wavelength conversion can be achieved by utilizing direct optical modulation of gain-clamping lasing light, i.e. converted signal. Frequency chirp of converted signal is numerically simulated, derived from single-mode rate equation and large-signal dynamic model. The results show that the mode frequency shifts toward the blue side near the leading edge and toward the red side near the trailing edge of the converted optical pulses. Parameters that affect frequency chirp, such as biased current, input optical power, extinction ratio and wavelength of input signal, and length of active region, are analyzed respectively. It provides a theoretical basis for improving the frequency chirp of converted signal.
Track strain field analysis for positing FBG sensor in fiber optic axle detecting
Jianjun Pan, Weilai Li, Yefang Zhang
FBG (Fiber Bragg Grating) sensor is suitable to detect track strain under harsh environment. In order to optimize its detecting efficiency, the key is to find out where the optimal detecting place is. This paper presents an FEA (Finite Element Analysis) method to analyze strain distribution of a track under load. The strain field is decomposed into three vector fields, and the optimal detecting place is determined by analyzing these vector fields. The related experiment and actual aplication verified the authenticity of this method.
Wavelength division multiplex optical fiber Bragg grating temperature array for ocean detection
Xingrong Li, Zhi Yang, Yongqian Li, et al.
The wavelength division multiplex FBG sensor system was researched.The sensor array was designed, and this system was used in ocean water temperature detection.This experiment was achived in South China Sea with 300 meters long Bragg grating array and got original signal wavelength.The wavelength data was processed and transformed into temperature.By curve fitting,the seawater profile temperature can be obtained.Simultaneously,contrastive test was completed with CTD,which was recommended by experts. By processing the data with MATLAB,the resolution attained 0.1°C, and the precision attained 0.2°C,the temperature changed trends was the same with CTD,and small deviation was exsited.
HDMI optical extender based on parallel optical transmitter and receiver
Zhixiang Luo, Zhishi Zhu, Hailiang Zhang
High-Definition Multimedia Interface(HDMI) can carry high quality multi-channel audio data and can carry all standard and highdefinition video formats. To send the information form video source to the display unit, the HDMI cable which carries four differential pairs is used. Now HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices, so the traditional copper wire cable imposes limits on signal transmission distance and signal quality at so high speed. Optical fiber is of low dispersion, which in turn has the strength of longer signal transmission distance and better signal transmission quality in comparison to the traditional copper wire cable. So the optical extender consisting of two modules - one transmitter and one receiver- is developed. The transmitter connects to a computer/DVD player etc. The receiver connects to a display. Between the two modules, four-core ribbon fibre is used to transmit the video and audio signals. HDMI needs four differential pairs, so we design the parallel optical transmitter based on VCSEL array and VCSEL driver chip HXT3404 from Gigoptix and the parallel optical receiver based on PIN array and transimpedance amplifier chip HXR3404. Each channel can reach 3.125Gbps, so the data speed of the optical extender is 12.5Gbps. The experiment shows that the optical extender can transfer the video and audio data to the display uint 100 meter away.
Optical phase transmultiplexing to support traffic grooming in transparent optical networks
Guo-Wei Lu
Advanced phase modulation formats, such as differential binary phase-shift keying (DPSK), differential quadrature phase-shift keying (DQPSK), and differential eight-ary phase-shift keying (D8PSK), and so on, have attracted considerable research attention as promising candidates for future optical communication systems. To accommodate different requirements such as nonlinear and dispersion tolerance, implementation complexity or spectral efficiency in different regions of networks, several different modulation formats are expected to coexist in the future optical network. For example, low-speed binary modulation formats may be deployed in the edge networks such as metro or access networks, whereas high-speed or multi-level modulation formats are preferred to be employed at the core networks to support high-speed long-haul transmission. To support the transparent cross-connection among various networks, and the traffic grooming from low-speed edge networks to high-speed core networks, optical phase transmultiplexing technology is highly desirable. In this paper, we report an all-optical phase interleaving technology to phase-multiplex 3x10-Gb/s differential phase-shift keying (DPSK) wavelength-division multiplexing (WDM) signals to a single 30-Gb/s DPSK, and an optical phase-modulated format conversion scheme to convert 2x10-Gb/s DPSK WDM to a single quadrature 20-Gb/s differential quadrature phase-shift keying (DQPSK). The proposed schemes are based on four-wave mixing effect in highly-nonlinear fiber. Different from conventional optical signal processing schemes, the proposed schemes are achieved in optical phase domain directly. Experiments were performed to verify the feasibility of the proposed schemes. Both of them could be applied in transparent optical networks to act as an optical phase transmultiplexer enabling traffic grooming and cross-connection among different networks.