Narrow-linewidth passively Q-switched fibre laser based on microsphere resonator

Abstract

We experimentally demonstrate a stable narrow-linewidth passively Q-switched fibre laser based on a microsphere resonator (MSR) and graphene saturable absorber (SA). The MSR made by the arc discharge method has the characteristics of easy fabrication, broad free spectral range (FSR) and flexibility. And it acts as a narrow band-pass filter to ensure narrow-linewidth operation. A stable passively Q-switched pulse with 0.016 nm narrow spectral linewidth is successfully achieved. The output pulse has the pulse width of 5.2 µs, repetition frequency of 28 kHz and high signal to noise ratio (SNR) of ∼60 dB. The results demonstrate that our works may provide an effective way to achieve narrow-linewidth pulsed fibre lasers.

KEYWORDS:

• Fiber laser
• Q-switched
• narrow linewidth

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (NSFC) [grant numbers 61905169, 61905168].