In this letter, we experimentally demonstrate multi-band linear frequency modulation (LFM) signal generation subjected to multi-input optical injection in an external cavity-based Fabry-Pérot laser diode (ECFP-LD). The ECFP-LD is a specially designed FP-LD with a self-injected single longitudinal mode tuned up to 10 nm. The non-linear dynamics in period-one oscillation in ECFP-LD subjected to multi-input optical injection shows unique characteristics for multi-band linear frequency modulation. In the proposed scheme, four external input beams are injected to ECFP-LD, among which one is power modulated with the saw-tooth like waveform, and others are with the constant power. The varying power beam red-shifts the self-injected mode of ECFP-LD and mode-hopping on attaining a particular power level. Hence, multi-band LFM signals are generated by beating self-injected and multi-input injected beams with a large time-bandwidth product (TBWP). The total bandwidths of 12GHz (LFM1: 33–36 GHz, LFM2: 29–32 GHz, LFM3: 25–28 GHz, LFM4: 22–25 GHz) for four-band linear frequency modulation signals with a TBWP of 12000 is measured. The generated multi-band LFM signal provides flexibility on central frequency tunability and dynamic chirp rate for a multifunctional radar system.

中文翻译：

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经多输入注入的外腔 FP-LD 中的多频带线性调频


在这封信中，我们通过实验演示了在基于外腔的法布里-珀罗激光二极管 (ECFP-LD) 中进行多输入光注入的多频带线性频率调制 (LFM) 信号生成。 ECFP-LD 是专门设计的 FP-LD，具有调谐至 10 nm 的自注入单纵模。经受多输入光注入的 ECFP-LD 第一周期振荡的非线性动力学显示了多频带线性频率调制的独特特性。在所提出的方案中，四束外部输入光束注入ECFP-LD，其中一束采用锯齿状波形进行功率调制，另一束采用恒定功率。变化的功率束使 ECFP-LD 的自注入模式发生红移，并在达到特定功率水平时进行跳模。因此，多频带 LFM 信号是通过以大时间带宽积 (TBWP) 击败自注入光束和多输入注入光束来生成的。测量了TBWP为12000的四频段线性调频信号的12GHz总带宽（LFM1：33-36GHz，LFM2：29-32GHz，LFM3：25-28GHz，LFM4：22-25GHz）。生成的多频段 LFM 信号为多功能雷达系统提供了中心频率可调性和动态线性调频频率的灵活性。