In this paper, we have successfully demonstrated a stable dual, triple and quad-wavelength generation of ytterbium-doped fiber by incorporating a non-adiabatic microfiber interferometer (N-MI) into the laser ring cavity. Three sets of dual-wavelength, two sets of triple-wavelength and one set of quad-wavelength with the same wavelength spacing of 4.24 nm for all sets of multiwavelengths over the range of 1035 nm to 1050 nm are obtained by means of a nonlinear polarization rotation mechanism. The side-mode suppression ratio (SMSR) is ~53 dBm while the wavelength fluctuation and maximum power are 0.01 nm and less than 0.6 dB, respectively. Such features offer flexibility in multiwavelength generation and a stable output, with addition to a reliable system at an ambient temperature.

This paper describes a demonstration of a passively dual-wavelength Q-switched ytterbium-doped fiber laser using a selenium bismuth-based saturable absorber. By utilizing a short-length photonic crystal fiber in a ring cavity and performing adjustments to the polarization state of an incorporated polarization controller (PC), we obtained a stable dual-wavelength Q-switched output at 1037.14 and 1037.69 nm, with maximum pulse energy of 0.65 nJ, shortest pulse width of 8.46 μs, and pulse repetition rate from 15.37 to 59.24 kHz. The Q-switched laser output consistently achieved high-power stability with a 0.8 dB maximum fluctuation over a period of 20 min.

In this work a passively Q-switched dual-wavelength ytterbium-doped fiber laser using a titanium dioxide-based saturable absorber is proposed and proven. The system also utilizes a side-polished fiber in a ring cavity configuration to obtain the desired pulse train. A stable dual-wavelength pulse output is obtained at 1034.7 and 1039.0 nm, with a maximum pulse energy of 2.0 nJ, and a shortest pulse width of 3.2 μs. The generated pulse train is stable, and has a pulse repetition rate from 31.2 to 64.5 kHz.