Highly Stable, Tapered Fiber Filter-Assisted, Multiwavelength Q-Switched Er-Doped Fiber Laser Based on Tm-Ho Fiber as a Saturable Absorber

A multiwavelength Q-switched erbium-doped fiber ring laser based on a section of Tm-Ho codoped fiber as a saturable absorber, assisted by a tapered optical fiber filter to stabilize the lasing performance is reported. The tapered fiber structure acts as a comb filter that allows us simultaneous lasing wavelengths at 1529.69, 1531.74, and 1533.48 nm with high stability. By adjusting the pump power, optical pulses with repetition rates from 10.46 to 61.8 kHz were obtained. The maximum average output power was 27.61 mW, while 496.34 nJ for the maximum pulse energy. The fiber laser exhibits a power deviation of ± 0.376 dB, an OSNR of 54 dB, and a spectral width of lasing lines of 0.06 nm, with stable multiwavelength lasing.