自由空间光通信(Free Space Optical Communication,FSOC)尤其是基于相干体制的卫星激光通信,正逐渐成为突破微波通信瓶颈、建设天地一体化网络、实现高速数据传输的重要手段。总结了欧空局、德国、日本及国内卫星相干激光通信的重要进...自由空间光通信(Free Space Optical Communication,FSOC)尤其是基于相干体制的卫星激光通信,正逐渐成为突破微波通信瓶颈、建设天地一体化网络、实现高速数据传输的重要手段。总结了欧空局、德国、日本及国内卫星相干激光通信的重要进展,给出了成功验证的相干激光通信系统的激光器、传输速率、多普勒频移补偿范围等参数,重点分析了基于Costas光锁相环(Optical Phase-Locked Loop,OPLL)技术的零差相干激光通信系统,并提炼出关键技术以及未来星间相干激光通信的发展趋势,可为卫星相干激光通信的研究提供一定的参考。展开更多
An optical phase locking method based on direct phase control is proposed.The core of this method is to synchronize the carrier by directly changing the phase of the local beam.The corresponding experimental device an...An optical phase locking method based on direct phase control is proposed.The core of this method is to synchronize the carrier by directly changing the phase of the local beam.The corresponding experimental device and the supporting algorithm were configured to verify the feasibility of this method.Phase locking can be completed without cycle skipping,and the acquisition time is 530 ns.Without an optical preamplifier,a sensitivity of-34.4 d Bm is obtained,and the bit error rate is 10^(-9) for 2.5 Gbit/s binary phase-shift keying modulation.The measured standard deviation of the phase error is 5.2805°.展开更多
Performance of high speed coherent optical communication systems has been investigated. A novel frequency tracking/locking automatical fre quency control (clock frequency tracking AFC, CFT AFC) scheme has been pre...Performance of high speed coherent optical communication systems has been investigated. A novel frequency tracking/locking automatical fre quency control (clock frequency tracking AFC, CFT AFC) scheme has been presented. The first Gb/s speed coherent optical communication system of China (1.1 Gb/s FSK optical communication system) has been achieved. The achievements of this paper are as follows: (1) Performance of coherent optical communication system has been investigated. A set of expressions are deduced. In the expressions, the effects of the LD line width, waveform of modulation signal, the signal phase jitter, intersymbol interference (ISI) and various kinds of noises are comprehensively included for the first time. (2) The jitter performance of coherent optical communication system is analyzed for the first time. The timing jitter theory of coherent optical communication system is achieved. (3) A novel frequency tracking/locking automatic frequency control (clock frequency tracking AFC, CFT AFC) scheme is presented. The scheme has three advantages compared with other AFC schemes: (a) frequency tracking/locking may be achieved efficiently; (b) timing clock may be extracted efficiently; and (c) the circuitry is simpler and steadier. (4) Performance of phase diversity (PD) optical communication systems is analyzed. The BER expressions of PD systems modulated under various kinds of signal waveforms are presented. The power penalties of PD systems resulted from signal phase jitter and ISI are deduced. (5) Performance of the light sources of coherent optical communication (external cavity LD and DFB LD) is analyzed. The non flat FM (frequency modulation) response of LD chip is compensated by external circuitry. The DFB LD module with 4.7 GHz FM response is achieved. (6) Compensation of fiber dispersion in optical communication is investigated. The practical fiber dispersion compensators are achieved. (7) The first Gb/s speed coherent optical Dissertation complete展开更多
An in-band optical signal-to-noise ratio （OSNR） monitoring technique with high resolution and large measurement range is demonstrated based on low- bandwidth coherent receiver and a tunable laser. The measurement ra...An in-band optical signal-to-noise ratio （OSNR） monitoring technique with high resolution and large measurement range is demonstrated based on low- bandwidth coherent receiver and a tunable laser. The measurement range of OSNR is from 10 to 25 dB and the resolution can be controlled about ±1 dB.展开更多
基金supported by the National Key R&D Program of China(No.2020YFB0408302)Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB43030400)+1 种基金National Natural Science Foundation of China(No.91938302)Key Project of Chinese Academy of Sciences(No.ZDRWKT-2019-1-01-0302)。
文摘An optical phase locking method based on direct phase control is proposed.The core of this method is to synchronize the carrier by directly changing the phase of the local beam.The corresponding experimental device and the supporting algorithm were configured to verify the feasibility of this method.Phase locking can be completed without cycle skipping,and the acquisition time is 530 ns.Without an optical preamplifier,a sensitivity of-34.4 d Bm is obtained,and the bit error rate is 10^(-9) for 2.5 Gbit/s binary phase-shift keying modulation.The measured standard deviation of the phase error is 5.2805°.
文摘Performance of high speed coherent optical communication systems has been investigated. A novel frequency tracking/locking automatical fre quency control (clock frequency tracking AFC, CFT AFC) scheme has been presented. The first Gb/s speed coherent optical communication system of China (1.1 Gb/s FSK optical communication system) has been achieved. The achievements of this paper are as follows: (1) Performance of coherent optical communication system has been investigated. A set of expressions are deduced. In the expressions, the effects of the LD line width, waveform of modulation signal, the signal phase jitter, intersymbol interference (ISI) and various kinds of noises are comprehensively included for the first time. (2) The jitter performance of coherent optical communication system is analyzed for the first time. The timing jitter theory of coherent optical communication system is achieved. (3) A novel frequency tracking/locking automatic frequency control (clock frequency tracking AFC, CFT AFC) scheme is presented. The scheme has three advantages compared with other AFC schemes: (a) frequency tracking/locking may be achieved efficiently; (b) timing clock may be extracted efficiently; and (c) the circuitry is simpler and steadier. (4) Performance of phase diversity (PD) optical communication systems is analyzed. The BER expressions of PD systems modulated under various kinds of signal waveforms are presented. The power penalties of PD systems resulted from signal phase jitter and ISI are deduced. (5) Performance of the light sources of coherent optical communication (external cavity LD and DFB LD) is analyzed. The non flat FM (frequency modulation) response of LD chip is compensated by external circuitry. The DFB LD module with 4.7 GHz FM response is achieved. (6) Compensation of fiber dispersion in optical communication is investigated. The practical fiber dispersion compensators are achieved. (7) The first Gb/s speed coherent optical Dissertation complete
基金Acknowledgements The authors would like to acknowledge the support of the National Natural Science Foundation of China （NSFC） （Grant No. 61435006） and the Program for New Century Excellent Talents in University （NCET-12-0679） in China.
文摘An in-band optical signal-to-noise ratio （OSNR） monitoring technique with high resolution and large measurement range is demonstrated based on low- bandwidth coherent receiver and a tunable laser. The measurement range of OSNR is from 10 to 25 dB and the resolution can be controlled about ±1 dB.
