基于双透镜外腔结构的窄线宽可调谐半导体激光器

Narrow-linewidth Tunable Semiconductor Lasers Based on Dual-lens External-cavity Structure

设计了一种具有独特双透镜外腔结构的可调谐窄线宽激光器,利用一个温控50 GHz的标准具提供ITU标准波长序列,通过一个压电陶瓷驱动的Fabry-Pérot可调谐滤波器选择一个标准波长实现单波长输出。实验结果表明:该激光器的调谐范围达到了1 525～1 580 nm,覆盖整个C波段,线宽为37.5 kHz,400 mA电流条件下的输出功率超过50 mW,边模抑制比超过50 dB,达到或超过相干通讯应用的要求和其他单片集成类器件的指标。另外,本结构具有位置容差大、调谐速度快(<3 ms)、易于实现超窄线宽以及波长微调等优点,待实现小型化和标准封装,其大规模应用将成为可能。

A narrow-linewidth tunable laser based on a unique dual-lens external-cavity structure was reported,in which a thermally-tuned 50 GHz etalon was utilized to provide standard ITU-grid wavelengths and a PZT-actuated tunable Fabry-Pérot filter to select wavelength.In experiment,the laser wavelength could be tuned from 1 525 to 1 580 nm,covering the whole C band.And it measured a linewidth of 37.5 kHz,an output power 50 mW at the 400 mA pump current,a SMSR 50 dB and a tuning speed 3 ms.The performance is superior to the requirements of coherent communication applications and the reported planar waveguide-based counterparts.Moreover,the dual-lens structure bears other merits such as high positioning tolerance and potential for ultra-narrow linewidth.It may have a wide application after miniaturization and standard packaging.