基于非相干光反馈半导体激光器产生微波频率梳

发布时间：2018-11-08 06:59

【摘要】：微波频率梳(MFCs)因可同时提供多频微波信号而在雷达探测、宽带无线通信等领域有着巨大的应用前景。传统的基于电学方式的微波频率梳产生方案虽能获得带宽达几个GHz甚至十几GHz的微波频率梳信号,但由于这种频率梳梳距不能灵活调节而使其应用受到了限制。另外,受电子频颈的限制,这种电子电路产生方案很难向更高带宽扩展。近年来,基于光学方式产生微波频率梳的方案受到了广泛关注。目前,基于非相干光反馈半导体激光器(SL)获取微波频率梳的研究还未见报道。就非相干光反馈系统而言,由于非相干光反馈只作用于载流子而不作用于光场,因而具有对反馈光相位变化不敏感的特征。另一方面,非相干光反馈系统属全光系统,不受电子器件带宽的限制,能满足超宽带微波频率梳产生的要求。基于此,本文提出了一种基于非相干光反馈半导体激光器产生可调谐超宽带微波频率梳的新型全光系统,并对该系统所产生的微波频率梳特征进行了理论分析和数值仿真研究。研究结果表明：在合适的参数条件下,非相干光反馈半导体激光器能工作在规则脉冲(RP)态,并且在10dB幅值变化范围内,能产生带宽超过40GHz的微波频率梳。对于一个固定注入电流,微波频率梳的梳距(重复频率)可以通过改变反馈延迟时间和反馈强度而调谐,且调谐范围随着注入电流的增加而增加。微波频率梳的线宽对反馈延迟时间和反馈强度的变化比较敏感,通过精细调谐反馈延迟时间和反馈强度可以得到低至几十KHz的线宽。另外,本文给出了微波频率梳的幅值变化、重复频率和线宽在反馈延迟时间和反馈强度构成的参数空间的分布图。
[Abstract]:Microwave frequency comb (MFCs) has great application prospect in radar detection, broadband wireless communication and so on because it can simultaneously provide multi-frequency microwave signal. The traditional microwave frequency comb generation scheme based on electrical mode can obtain microwave frequency comb signal with bandwidth up to several GHz or even more than ten GHz, but its application is limited because the frequency comb distance can not be adjusted flexibly. In addition, due to the limitation of electronic frequency neck, this electronic circuit generation scheme is difficult to extend to higher bandwidth. In recent years, microwave frequency comb generation based on optical mode has received wide attention. At present, the study of obtaining microwave frequency comb based on incoherent optical feedback semiconductor laser (SL) has not been reported. As far as incoherent optical feedback system is concerned, incoherent optical feedback is insensitive to the phase change of feedback light because it acts only on carriers and does not act on light field. On the other hand, the incoherent optical feedback system is an all-optical system, which is not limited by the bandwidth of electronic devices and can meet the requirements of ultra-wideband microwave frequency comb generation. Based on this, a novel all-optical system based on incoherent optical feedback semiconductor laser to generate tunable ultra-wideband microwave frequency comb is proposed. The characteristics of microwave frequency comb generated by the system are theoretically analyzed and numerically simulated. The results show that the incoherent optical feedback semiconductor laser can work in the regular pulse (RP) state under suitable parameters, and in the range of 10dB amplitude, the microwave frequency comb with bandwidth exceeding 40GHz can be generated. For a fixed injection current, the comb distance (repetition rate) of the microwave frequency comb can be tuned by changing the feedback delay time and the feedback intensity, and the tuning range increases with the increase of the injection current. The linewidth of microwave frequency comb is sensitive to the variation of feedback delay time and feedback intensity. By fine tuning feedback delay time and feedback intensity, the linewidth of as low as dozens of KHz can be obtained. In addition, the amplitude variation, repetition rate and linewidth of microwave frequency comb in the parameter space of feedback delay time and feedback intensity are given.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248.4

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