A III-V-on-Si ultra-dense comb laser

作者：Wang Zhechao^*; Van Gasse Kasper; Moskalenko Valentina; Latkowski Sylwester; Bente Erwin; Kuyken Bart; Roelkens Gunther^*

来源：Light: Science and Applications , 2017, 6(5): e16260.

DOI：10.1038/lsa.2016.260

• mode-locked lasers
• near-infrared spectroscopy
• optical frequency comb
• semiconductor lasers
• silicon photonics

Optical frequency combs emerge as a promising technology that enables highly sensitive, near-real-time spectroscopy with a high resolution. The currently available comb generators are mostly based on bulky and high-cost femtosecond lasers for dense comb generation (line spacing in the range of 100 MHz to 1 GHz). However, their integrated and low-cost counterparts, which are integrated semiconductor mode-locked lasers, are limited by their large comb spacing, small number of lines and broad optical line-width. In this study, we report a demonstration of a III-V-on-Si comb laser that can function as a compact, low-cost frequency comb generator after frequency stabilization. The use of low-loss passive silicon waveguides enables the integration of a long laser cavity, which enables the laser to be locked in the passive mode at a record-low 1 GHz repetition rate. The 12-nm 10-dB output optical spectrum and the notably small optical mode spacing results in a dense optical comb that consists of over 1400 equally spaced optical lines. The sub-kHz 10-dB radio frequency linewidth and the narrow longitudinal mode linewidth (<400 kHz) indicate notably stable mode-locking. Such integrated dense comb lasers are very promising, for example, for high-resolution and real-time spectroscopy applications.

• 出版日期2017-5-19