Wavelength tunable lasers are essential devices in many fields, such as opticalfibercommunication systems, optical fibersensing and high-resolution spectroscopy. Phase noise of tunable laser sources is becomingimportant in applications forwherehigh-bitrate and high-resolutionare required. For instance, when tunable lasers are used as transmitters in coherent optical communication systems, the performance of the system can be significantly degraded by large laser phase noise as a result of the distortional constellation points and consequently the increased bit error rate (BER).So it is of great importance to investigate the phase noise characteristics oftunablelasers.
Prof. Yonglin Yu’s group from Wuhan National Lab for Optoelectronics, cooperating with Prof. L. P. Barry’s group from Dublin City University(DCU), continued investigations on phase noise of tunable semiconductor lasers. Recently,based on transmission line model, a comprehensive simulation model is developed to simulate the phase noise of themodulated grating Y-branch(MGY)laser. Simulation results achieved are in good agreement with the experimental measurements, which are obtained by using anewphase noise measurement techniquedeveloped by the DCU group. The results are helpful to understand the phase noise behaviors of the MGY laser and to optimize the semiconductor tunable laser design.
This work, published inIEEE Journal of Selected Topics in Quantum Electronics(vol.23, No.6, Nov/Dec, 2017), was supported in part bythe National Natural Science Foundation of China under Grant 61675073, in part by Fundamental Research Funds for the Central Universities under Grant 2016YXZD004, in part by 111 Program under Grant B07038, in part by China Scholarship Council, and in part by the Science Foundation Ireland through the IPIC (12/RC/2276) and CONNECT (13/RC/2077) research programmes.
Fig. 1. Structure of the MGYlaser
（a） (b)
Fig. 2. FM-noise spectra of the MGY laser, compared with ones of the SGDBR laser (a) simulated;(b) measured.
