Ti2C MXene for multi-wavelength enhancement in S-band Q-switched thulium doped fluoride fiber laser

Abstract

A titanium carbide (Ti2C)-based saturable absorber was demonstrated in a compact thulium-doped fluoride fiber laser (TDFFL) configured to generate stable microsecond pulses in single- and multiwavelength operations. An in-line Mach-Zehnder interferometer (MZI) based on a two-mode fiber was incorporated into the laser cavity to generate a birefringent effect that has a fixed free spectral range (FSR) and an extinction ratio (ER) of 0.83 nm and 6.17 dB, respectively. At the maximum pump power of 250 mW, the TDFFL generated single-wavelength Q-switched pulses with a maximum frequency of 35.20 kHz, a pulse width of 3.30 µs, and pulse energy of 2.55 nJ, respectively. In the multiwavelength Q-switching operation, the laser-generated pulses have a frequency, pulse width, and pulse energy of 27.02 kHz, 3.17 µs, and 1.79 nJ, respectively. The proposed single- and multiwavelength Q-switched fiber lasers were stable and compact, making them suitable for industrial applications.