【作者】 陈言樑；

【导师】 张新亮；

【作者基本信息】 华中科技大学 ， 光学工程， 2006， 硕士

【摘要】 随着光纤通信技术的发展和通信业务需求的不断增加,光纤通信系统的速率越来越高。性能稳定,能产生高质量超短脉冲的光源,在光纤通信中也将起着越来越重要的作用,直接影响着整个光纤通信系统的性能。在本论文中,利用半导体光放大器联合普通单模光纤来实现光脉冲压缩,从而产生光纤通信时分复用系统所需要的超高速脉冲源。本论文分析了光脉冲压缩的基本原理,并对利用半导体光放大器压缩光脉冲进行了理论分析,最后进行了实验论证。实验表明,利用半导体光放大器压缩光脉冲足以满足现有光通信系统对于光源的要求。本文完成的主要工作如下:(1)介绍了光纤通信技术的发展历程,以及未来光纤通信技术的发展方向。分析了光脉冲压缩技术在光纤通讯系统中的重要作用和地位。详细介绍了现今已有的各种光脉冲压缩方法,如光纤-光栅对压缩器,孤子效应压缩和色散递减光纤等,并对其基本原理进行了简略地说明。(2)对光脉冲压缩的基本原理进行了详细地说明。分别论述了群速度色散和自相位调制对光纤中各种不同光脉冲传输的影响:群速度色散将对光脉冲产生一个线性啁啾。而自相位调制对光脉冲产生的啁啾仅在中心部位具有近似线性特性。当这两者引入的啁啾相反时,将对光脉冲实现压缩。利用Matlab程序,模拟了不同光脉冲入射后,群速度色散与自相位调制对光脉冲产生的不同啁啾,并进行了比较和分析。(3)采用SOA经典分段模型,分析了SOA中的脉冲传输,得到光脉冲在经过SOA后的啁啾,并利用Matlab程序进行数值模拟,研究了脉冲啁啾随SOA注入电流与泵浦脉冲峰值功率变化的规律。在此基础上论证了利用SOA进行光脉冲压缩的可行性。并利用Optisystem系统模拟了基于半导体光放大器的光脉冲压缩。(4)实验论证了利用半导体光放大器压缩光脉冲的方案。结果表明,通过合理选取单模光纤的长度,可使50ps光脉冲压缩到10ps。更多还原

【Abstract】 The proliferating growth of communication capacity demand generated by multiple new applications and expected to last at least for the next decade will stimulate the development of flexible transport services. Optical fiber communication plays an important role in satisfying the demand due to the huge bandwidth of fiber. OTDM systems include ultrashort optical generation: to enable multiplexing and demultiplexing with low interchannel crosstalk. OTDM system need to operate with return-to-zero optical pulses. Pulse compression is a very important part of the ultrashort optical pulse generation.In this thesis, we analyse the basic principle of the optical pulse compression,and a new designed model of the optical pulse compressor, which is based on a semiconductor optical amplifier(SOA),has been presented in this paper. The thesis focus on the following four parts:(1) The history of optical fiber communication is introduced. It is so important that pulse compression plays in the ultrashort optical pulse generation. Some pulse compressors such as fiber-grating compressor, DDF- Dispersion-Decreasing Fiber pulse compression and so on, have been introduced.(2)The principle of the pulse compress is been explained.The influence of the Group Velocity Dispersion(GVD) and Self-Phasic Modulation(SPM) to optical pulse have been mode clear and compared. The matlab numerical simulations reveal the optical pulse chirp form the GVD and SPM separately.(3)The chirp from the SOA when an optical pulse pass has been analysed and simulated. We study the change between the chirp and SOA input electric current, and we learn the change between the chirp and SOA pump pulse power. The new pulse compression based on the SOA is simulated by Optisystem.(4)Experiments prove that the new optical pulse compression based on the SOA is feasible.A fifty ps optical pulse can be compressed into a ten ps pulse by a SOA and a suitable length fiber.更多还原