Compact metrological frequency comb stabilized with optical injection locking assisted by long-term optoelectronic correction

摘要

In this paper, we present new and encouraging results in the road towards démocratisation of optical frequency combs for metrology applications out of the laboratories. We study a compact InGaAs based Quantum-Dash Mode Locked Laser Diode (QD-MLLD) at 1.55μm generating high stable and low noise optical pulses with a repetition rate higher than 10 GHz [1]. The source is a 10.1 GHz mode spacing Fabry-Perot laser with extremely high internal correlation between modes. The spectral purity of the beat-note resulting in the beating of all the modes is lower than 50 kHz while the typical linewidth of optical modes is about 50 MHz. Thanks to injection locking with an External Cavity Laser Diode (ECLD) in one of the 125 modes, we succeed in a linewidth reduction by 500 of the MLLD optical modes, corresponding to the linewidth of the master laser.