Dynamic Intermode Beat Frequency Control of an Optical Frequency Comb Single Section Quantum Dot Laser by Dual-Cavity Optical Self-Injection

• Published in: IEEE photonics journal Vol. 11; no. 5; pp. 1 - 8
• Main Authors: Stutz, Sebastian, Auth, Dominik, Weber, Christoph, Drzewietzki, Lukas, Nikiforov, Oleg, Rosales, Ricardo, Walther, Thomas, Lester, Luke F., Breuer, Stefan
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.10.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Beat frequencies; Cavity resonators; Delay time; Frequency control; Indium gallium arsenides; intermode beat frequency; Laser mode locking; Lasers; Open systems; Optical attenuators; Optical frequency; Optical frequency comb laser; Optical variables control; Phase coherence; Quantum dot lasers; Quantum dots; self mode-locking; self-injection; stochastic modelling; time-domain modelling; Tuning
• ISSN: 1943-0655; 1943-0647
• DOI: 10.1109/JPHOT.2019.2932452

Dynamic frequency tuning of the 40.67 GHz intermode beat frequency of a 1255 nm emitting 1 mm long monolithic self mode-locked single section optical frequency comb InAs/InGaAs quantum dot laser across 70 MHz is experimentally demonstrated by fine-delay dual-cavity controlled all optical self-injection. Fiber-based macroscopic optical delay lengths are 9.4 m (round-trip time of 62.7 ns) and 16.5 m (round-trip time of 110.1 ns), the maximum studied microscopic delay tuning times are 40 ps and the optical self-injection strengths are below 0.02%. For selected delay times, the lowest intermode beat frequency line width amounts to 2 kHz indicating an improvement of carrier phase coherence by a factor of 700 as compared to the free-running laser. We validate these experimental results by a simple and universal stochastic time-domain model which is applied for the first time to model a self mode-locked quantum dot laser subject to optical self-injection. Modeling results are in good quantitative agreement.