Tunable Two-Color Lasing Emission Based on Fabry-Perot Laser Diode Combined With External Cavity Feedback

Abstract

In this paper, two-color lasing emission is experimentally demonstrated by employing a multimode Fabry-Perot laser diode (MMFP-LD) associated with external cavity of two tunable filters and an erbium-doped fiber amplification (EDFA), whose difference frequency is quasi-continuously tunable from several hundred GHz to more than 2 THz. The obtained side-mode suppression ratio (SMSR) in the output spectrum is around similar to 20 dB, and the modulation depth of simulated beat signal converted by two emission modes rapidly decayed as increasing the frequency separation. In addition, optical behaviors induced by mode competition and four-wave mixing are observed and discussed, while the difference frequency was shortened to GHz regime.