Dual-wavelength interval tunable and multi-wavelength switchable high-performance fiber laser based on four-leaf clover suspended core fiber filter

Abstract

In this paper, a dual-wavelength interval tunable and multi-wavelength switchable fiber laser with high performance is proposed and experimentally demonstrated by using a four-leaf clover suspended core fiber (FLCSCF) filter. The filter, based on mode interference (MI), is fabricated by splicing a 10.5 cm long FLCSCF between two sections of single mode fiber (SMF). The FLCSCF has favorable mode confinement and low transmission loss, which is beneficial for forming a comb-like transmission spectrum with a high extinction ratio. By inserting the MI filter based on FLCSCF into a ring erbium-doped fiber laser (EDFL), switchable single- to six-wavelength lasing outputs are obtained; the optical signal to noise ratio (OSNR) of all lasing outputs is above 50 dB. Dual-wavelength lasing outputs with tunable wavelength intervals are achieved by applying strain on the filter and the maximum tunable range of dual-wavelength lasing outputs can reach up to 41 nm. In addition, six-wavelength lasing outputs exhibit good stability with the wavelength shift less than 0.04 nm and the peak power fluctuation lower than 1.5 dB. Such a multi-wavelength fiber laser (MWFL) with improved performance has great application potential in microwave communications and laser strain sensing.