This letter demonstrates a tunable multi-band linear frequency modulation (LFM) signal with improved and unidentical bandwidths subjected to optical injection in a distributed-feedback (DFB) laser. In the proposed scheme, an optical beam is divided into two paths, one modulating with a baseband LFM signal and another with a power-varying signal. The basic principle of the proposed scheme is the optical beating of the carrier-suppressed $\pm 1^{\text {st}}$ sidebands in one path and the red-shifted emission mode of the DFB laser after optical injection in another path. In the experiment, the generated three LFM signals have the bandwidths of 11.5 GHz (from 23.0 to 34.5 GHz), 7.5 GHz (from 15.0 to 22.5 GHz), and 4 GHz (from 8.0 to 12.0 GHz) in one period of $1~\mu $ s. Moreover, we analyze the effect of the injected beam’s frequency and power on the bandwidth tunability of the generated LFM signals.

中文翻译：

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DFB激光器中的光注入会导致带宽不相同的多频带LFM信号

这封信演示了在分布式反馈（DFB）激光器中进行光注入后，具有改进的和不相同带宽的可调多频带线性调频（LFM）信号。在提出的方案中，光束被分为两条路径，一条通过基带LFM信号进行调制，另一条通过功率变化信号进行调制。该方案的基本原理是抑制载波的光学拍打 $ \ pm 1 ^ {\ text {st}} $ 一条路径中的边带和另一条路径中的光注入后DFB激光器的红移发射模式。在实验中，生成的三个LFM信号在一个周期的一个周期内具有11.5 GHz（从23.0到34.5 GHz），7.5 GHz（从15.0到22.5 GHz）和4 GHz（从8.0到12.0 GHz）的带宽。 $ 1〜\亩$ s。此外，我们分析了注入光束的频率和功率对所产生的LFM信号的带宽可调性的影响。