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.

本文提出了一种高性能的双波长间隔可调和多波长可切换光纤激光器，并通过使用四叶三叶草悬浮芯光纤（FLCSCF）滤波器进行了实验验证。通过在单模光纤（SMF）的两个部分之间拼接10.5厘米长的FLCSCF来制造基于模干扰（MI）的滤波器。FLCSCF具有良好的模式限制和低传输损耗，这有利于形成具有高消光比的梳状传输光谱。通过将基于FLCSCF的MI滤波器插入到掺ring的环形光纤激光器（EDFL）中，可获得可切换的单波长至六波长激光输出。所有激光输出的光信噪比（OSNR）均高于50 dB。通过在滤镜上施加应变，可以实现具有可调波长间隔的双波长激光输出，并且双波长激光输出的最大可调范围可以达到41 nm。另外，六波长激光输出具有良好的稳定性，波长偏移小于0.04 nm，峰值功率波动小于1.5 dB。这种性能提高的多波长光纤激光器（MWFL）在微波通信和激光应变传感中具有巨大的应用潜力。