CW injection locking of a mode-locked semiconductor laser as a local oscillator comb for channelizing broad-band RF signals

Abstract

CW injection locking of mode-locked semiconductor lasers has been experimentally demonstrated. The phases of the mode-locked frequency comb are shown to be coherent with that of the master CW laser. The pulsewidth of the mode-locked laser remains almost unchanged (<2 ps) for a broad range of injection power (028 to 012 dBm). Pulling of the entire modelocked frequency comb by 400 MHz has been demonstrated. The coherent multifrequency source can be used as a local oscillator comb for coherent optical channelizers for ultrawide-band RF signals.

Optical Frequency Comb Generation Using Dual-Mode Injection-Locking of Quantum-Dash Mode-Locked Lasers: Properties and Applications

“…A number of techniques have been proposed for the generation of OFCs such as using cascaded intensity and/or phase modulators [7], [8], fibre or semiconductor based ring-cavity mode-locked lasers [9], [10], direct modulation of gain-switched discretemode lasers [11], and semiconductor mode-locked lasers [12].…”

CW injection locking for long-term stability of frequency combs

“…It can be used in power amplifiers to take advantage of high gain in regenerative amplifier systems while maintaining the spectral qualities of a less intense master oscillator. In the multi-wavelength regime, injection locking has been shown to lock a mode-locked laser quite effectively, with the output being a set of phase-locked frequency components anchored by the injection frequency 9 . The mode-locking mechanism, whether passive or active, locks the phases of the frequency components, producing a comb, while the injection mechanism locks the optical frequency to the injection seed frequency, stabilizing the comb.…”

Injection-locked passively mode-locked semiconductor laser for optical heterodyne detection using a single axial mode

“…A well-known coherent detection method, optical heterodyne detection has been widely studied in a variety of coherent communication applications owing to the significantly improved signal-tonoise ratio and narrow channelization of broad-band signals as compared to common direct detection methods [1]. Nonetheless, most coherent mixing processes in optical heterodyne detection require strict optical frequency and phase synchronization between the carrier frequencies in master oscillators (MO) and the frequency combs in local oscillators (LO).…”