Tang Liwei, Li Liangbo, Li Jiachen, Chen Minghua
Opt Express. 2022 Aug 15;30(17):30420-30429. doi: 10.1364/OE.465858.
Narrow linewidth and fast-chirped frequency are essential in frequency-modulated continuous-wave lasers. We introduce a laser that meets these requirements by coupling a distributed feedback laser with an external high-Q microring resonator, where a bulky stacked piezoelectric chip is attached to the resonator for fast tuning. The laser demonstrates an ultranarrow intrinsic linewidth of 22 Hz in the self-injection-locked state. Actuated by the bulky piezoelectric chip, the maximum triangular actuation bandwidth can reach 100 kHz. The driving voltage is filtered to avoid a resonant mechanical mode, obtaining the minimum residual linearity error at 10 kHz with a 4.2 GHz tuning range. A light detection and ranging system was set up for a proof-of-concept experiment, demonstrating a high detection precision with standard deviations of 2.7 and 4.0 cm for targets at 15 and 30 m, respectively.
窄线宽和快速啁啾频率在调频连续波激光器中至关重要。我们介绍一种激光器，它通过将分布反馈激光器与外部高Q微环谐振器耦合来满足这些要求，其中一个笨重的堆叠式压电芯片附着在谐振器上以实现快速调谐。该激光器在自注入锁定状态下展现出22 Hz的超窄本征线宽。由笨重的压电芯片驱动时，最大三角驱动带宽可达100 kHz。对驱动电压进行滤波以避免谐振机械模式，在4.2 GHz调谐范围内，10 kHz时获得最小残余线性误差。搭建了一个光探测与测距系统用于概念验证实验，对于15 m和30 m处的目标，分别展示出2.7 cm和4.0 cm标准差的高探测精度。
