Polarization switching in the 2-µm Tm:KLu(WO2)4 laser

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].…”

“…To date, various schemes have been utilized to achieve passive Q-switching near 2 μm [8][9][10][11][12][13][14][15][16][17][18]. Generally, the passive Q-switching operation in fiber lasers could be achieved by employing a semiconductor saturable absorber mirror (SESAM [8,9]) or Cr 2+ : ZnSe crystal [10][11][12] as the saturable absorber.…”

“…To date, various schemes have been utilized to achieve passive Q-switching near 2 μm [8][9][10][11][12][13][14][15][16][17][18]. Generally, the passive Q-switching operation in fiber lasers could be achieved by employing a semiconductor saturable absorber mirror (SESAM [8,9]) or Cr 2+ : ZnSe crystal [10][11][12] as the saturable absorber. However, the additional optical components such as lens and mirrors were required in the laser cavity, which leads to larger insertion loss and more complicated design.…”

Orthogonally polarized dual-wavelength single-longitudinal-mode Tm,Ho:LLF laser

“…In 2011, V. Jambunathan et al observed the dual-wavelength output in a diodepumped Ho,Tm:KLu(WO 4 ) system, one generated from Tm ions tuned in the 1854-1980 nm range and the other from Ho ions tuned in the 1971-2063 nm range [23]. More recently, M. Segura et al reported simultaneous CW laser emissions at 1922 and 1946 nm from the Tm:KLu(WO 4 ) crystal, which is accompanied by polarization switching [11,24]. In this paper, we report on a CW simultaneous dual-wavelength SLM Tm,Ho:LLF laser with orthogonal polarization, near room temperature.…”