2.4-W Narrow-Linewidth Q-Switched $\hbox{Tm}^{3+}$-Doped Double-Clad Fiber Laser

Abstract

A narrow-linewidth 793-nm diode-pumped Tm 3þ -doped double-clad silica fiber laser operated at 2 m and actively Q-switched with an acousto-optic modulator is reported. Using a fiber Bragg grating as an output coupler, approximately 0.1-nm linewidth at 1996.8-nm pulses is derived at 80-kHz repetition rate. The maximum average output power is above 2 W for 11.6-W absorbed pump power. Less than 150-ns pulse is obtained at the repetition rate of 30 kHz. The laser is a promising seed laser for amplification in a master oscillator power amplifier system.

A stable 2 μm passively Q-switched fiber laser based on nonlinear polarization evolution

“…Due to the 2 μm operation wavelength at eye safe range, the thulium-doped Q-switched fiber lasers have attracted considerable research interest in recent years. Both the active and passive methods are used in the Q-switched fiber lasers at the 2 μm wavelength [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Regarding the actively Q-switched method, the acoustic-optical modulation and electro-optical modulation were most frequently employed inside the laser cavity to achieve Q-switched pulse [3][4][5][6][7].…”

“…Both the active and passive methods are used in the Q-switched fiber lasers at the 2 μm wavelength [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Regarding the actively Q-switched method, the acoustic-optical modulation and electro-optical modulation were most frequently employed inside the laser cavity to achieve Q-switched pulse [3][4][5][6][7]. However, all actively Q-switched lasers contain the bulk elements that make the laser system complicated.…”