Wavelength locking of Er-doped random fiber laser

Abstract

This paper demonstrates the wavelength locking of a coherent random lasing system, i.e. an Erbium-doped random fiber laser with a disordered array of fiber Bragg gratings. To lock lasing modes of the disordered system, an external seed light from a tunable laser was introduced into the cavity. It was found that different emission wavelengths/modes can be selected to emit separately through injection locking. The wavelength fluctuation of the output is less than 0.01%, and the power fluctuation is less than 4%. The proposed method is also applicable to general disordered systems, providing an efficient way to control or select light emission in these systems.

Single‐Shot Interaction and Synchronization of Random Microcavity Lasers

“…The pump spot illuminated the two nodes unequally, which enabled a master‐slave coupling regime, that is, one node would follow the output of the other node through injection locking. [ 34 ] The coupling strength between the two nodes was precisely controlled by connecting the MMFs with a variable optical attenuator. The two nodes’ output spectra were monitored by two identical spectrometers to analyze the interaction and synchronization of the output pulse‐by‐pulse.…”

“…These are direct evidence of master–slave synchronization between the two nodes through injection locking. [ 34,35 ] The injection performed as the seed light (which is much stronger than spontaneous emission) to influence the nodes’ output mutually, and thus the two nodes’ spectra showed redistributed intensity. In the authors’ case, the injection was strong enough, and the two nodes were made to emit similar spectra, the so called synchronization.…”

Highly-stable optical injection wavelength locking of Er-doped random fiber lasers

“…Based on multimode interference effect spectrum clipping, Wu et al demonstrated a spectrum clipping scheme a spectrum tailoring scheme of RFL by changing the filter length [25]. Hu et al realized mode-locked laser pulses by passive mode locking with selectable repetition rate [26], and employed a FBG as one reflector of the cavity and achieved the locking wavelength range of 0.5 nm from 1552.3 to 1552.7 nm, with the wavelength and power fluctuation less than 0.01% and 4%, respectively [27]. By further exploring the above schemes and inspired by the optical injection theory of lasers [28][29][30], it is found that the optical injection locking of RFL systems was still an open question, especially in the incoherent RFL systems based on the random distributed Rayleigh scattering.…”