Narrow linewidth semiconductor laser

摘要

A laser system (100) includes a semiconductor laser (115) having a laser driver (112) coupled thereto. An output of the semiconductor laser (115) is optically coupled to an input of an optical splitter (135) that provides outputs including or coupled to a first branch having a first branch fiber (137) coupled to a feedback reflector (140) which provides a cavity boundary that defines a passive secondary cavity for the semiconductor laser (115), and a second branch including a back reflection reduction device (145). The roundtrip attenuation from an output facet of the laser (115) to the feedback reflector (140) is from -30 dB to -80 dB. The laser driver (112) provides sufficient drive stability so that a frequency variation of the semiconductor laser (115) is less than one free spectral range (FSR) of the secondary cavity. The output of said system is taken after the back reflection reduction device (145).