外部光扰动下1550nm-VCSELs获取窄线宽光子微波的研究

发布时间：2018-01-17 02:23

本文关键词：外部光扰动下1550nm-VCSELs获取窄线宽光子微波的研究　出处：《西南大学》2016年硕士论文　论文类型：学位论文

【摘要】：光载无线(Radio-over-Fiber,RoF)通信技术由于具有无线微波通信的便捷性,以及光纤通信的大容量传输能力等特性,在下一代宽带无线通信技术中具有诱人的应用前景。而作为关键支撑技术之一的光子微波技术成为近年来的研究热点。目前,国内外学者已经提出了多种光子微波方案,比如基于两独立激光的拍频获得微波信号的光外差法、基于光电调制器的外部调制法、基于多段集成的双模激光器的双模输出以及基于光电反馈环的光电微波振荡法等。这些方法也都有着各自的优势和缺陷。近些年来,利用半导体激光器的周期性振荡来获得光子微波的方案受到了相关学者们的关注。目前,从半导体激光器的周期性振荡中来获得微波信号主要利用的是边发射半导体激光器(EEL),对于近些年飞速发展的垂直腔表面发射激光器(VCSEL)的研究还比较少。而和EEL相比,VCSEL有一系列优势,如:低阈值电流、易集成、易与光纤耦合、大调制带宽、制造成本低廉等,很可能在将来成为代替EEL成为下一代光通信以及信号处理的核心器件。本文提出一种基于1550 nm垂直腔表面发射激光器(1550 nm-VCSEL)获取高质量微波信号的全光方案。在该方案中,通过采用波长位于VCSEL中被抑制模式的中心波长附近、振动方向与VCSEL中主导模式相同的偏振光注入(即平行注入)1550 nm-VCSEL获取高频微波,并借助双光反馈对该高频微波的线宽进行窄化。首先,基于VCSEL的自旋反转模型(SFM),从理论上分析了采用该方案产生微波信号的可行性。进一步地,构建了相应的实验系统,对该方案产生的微波特性进行初步实验研究。研究结果表明:在合适的注入条件下,1550 nm-VCSEL能够产生30 GHz左右的微波信号,但该信号的线宽较宽(百兆水平);引入双光反馈后,微波线宽可被压窄2个数量级以上,得到了线宽低于1 MHz,信噪比大于40 dB的微波信号。由于本文提出的方案为全光结构,不需要使用昂贵的高频电子器件,因此对于发展低成本、高性能的窄线宽光子微波技术可提供一定的技术借鉴。
[Abstract]:Because of the convenience of wireless microwave communication and the large capacity of optical fiber communication, the optical wireless radio over-Fibero RoF communication technology has the characteristics of wireless microwave communication and optical fiber communication. It has an attractive application prospect in the next generation broadband wireless communication technology. As one of the key supporting technologies, photonic microwave technology has become a research hotspot in recent years. Scholars at home and abroad have proposed a variety of photonic microwave schemes, such as optical heterodyne method based on two independent laser beat frequency to obtain microwave signal, and external modulation method based on photoelectric modulator. The dual-mode output based on multi-segment integrated dual-mode laser and the optoelectronic microwave oscillation method based on photoelectric feedback loop have their own advantages and disadvantages. In recent years, these methods have their own advantages and disadvantages. The scheme of obtaining photonic microwave by using the periodic oscillation of semiconductor laser has attracted the attention of related scholars. The edge emitting semiconductor laser (EELL) is used to obtain the microwave signal from the periodic oscillation of the semiconductor laser. The research of VCSELL, which has been developing rapidly in recent years, is relatively few. Compared with EEL, VCSEL has a series of advantages, such as low threshold current, easy integration. Easy to coupling with optical fiber, large modulation bandwidth, low manufacturing cost, etc. It is likely to become the core device of next generation optical communication and signal processing instead of EEL in the future. In this paper, a 1550nm vertical cavity surface emitting laser is proposed. The all-optical scheme for obtaining high-quality microwave signals by 1550nm-VCSEL. in this scheme. The adopted wavelength is located near the central wavelength of the suppressed mode in the VCSEL. The vibrational direction is the same as the dominant mode in VCSEL (I. E. parallel injection of 1550 nm-VCSEL) to obtain high frequency microwave. The linewidth of the high frequency microwave is narrowed by double optical feedback. Firstly, the spin inversion model based on VCSEL is proposed. The feasibility of using this scheme to generate microwave signal is analyzed theoretically. Furthermore, the corresponding experimental system is constructed. The experimental results show that the microwave signal of about 30 GHz can be produced under the suitable injection conditions for 1550 nm-VCSEL. However, the line width of the signal is wide (100 megabytes horizontal); When double optical feedback is introduced, microwave linewidth can be reduced by more than 2 orders of magnitude, and microwave signals with linewidth less than 1 MHz and signal-to-noise ratio (SNR) greater than 40 dB can be obtained. The proposed scheme is an all-optical structure. It is not necessary to use expensive high frequency electronic devices, so it can be used as a reference for the development of low cost and high performance narrow linewidth photonic microwave technology.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN248

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