Optical and RIN Spectrum Improvements in Necked Waveguide High-Power DFB Laser Diode

• Published in: IEEE photonics technology letters Vol. 34; no. 5; pp. 275 - 278
• Main Authors: Liu, Yihui, Huang, Yongguang, Zhang, Ruikang, Hou, Lianping, Lu, Dan, Zhao, Lingjuan, Wang, Wei
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: coherent collapse; continuous wave (CW); corrugation pitch modulated (CPM); Distributed feedback lasers; external optical feedback; Gratings; high power DFB; Injection current; Laser feedback; necked waveguide; Noise intensity; Optical feedback; Optical polarization; Optical waveguides; Relative intensity noise; relative intensity noise (RIN); Semiconductor lasers; Waveguide lasers; Waveguides
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2022.3150799

A novel high power distributed feedback (DFB) laser is proposed which uses a partially narrow waveguide and corrugation pitch modulated (CPM) phase shift grating. Compared with conventional DFB lasers with constant waveguide width, these necked DFB lasers have greater improvements in terms of optical and relative intensity noise (RIN) spectrum. They are less sensitive to external optical feedback (EOF) and increase the range of the injection current for single longitudinal mode (SLM) operation. It can not only suppress the multimode lasing state under high injection current and EOF intensity, but also realize the SLM operation with RIN < −135 dB under a EOF intensity of less than −15 dB in the current range of 150 mA ~ 350 mA. Therefore, the range of injection current for SLM operation was increased for continuous wave (CW) light sources in silicon-based hybrid photonic integration applications.