Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
Yan Ge
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
Hongchun Wu
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
Jinhui Li
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
Huagang Liu
Department of Electrical and Computer Engineering, National University of Singapore, Singapore
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
Q-switched and polarized Ho lasers are the ideal driving source for mid-infrared radiation via optical parametric oscillation. Although intra-cavity pumping is an efficient way to achieve the Ho laser oscillation at 2.1 μm, which also facilitates the direct use of common diodes in a compact structure, it was demonstrated to be not suitable for Q-switching due to the saturable effect of the Ho-doped gain medium. Here, we report a RbTiOPO4 Q-switched intra-cavity pumped laser via integrating the Tm-doped and Ho-doped gain medium into a composite structure and decoupling the Tm laser from the Ho laser before it was modulated by the RbTiOPO4 crystal. The shortest pulse of 41 ns at repetition frequency of 1 kHz was obtained with a peak power of 7.5 kW. By competing with the intensified self-pulsing, the maximum pulse repetition frequency was found to reach 7 kHz, which was half the driving frequency of the electro-optical modulator. The results pave the way for achieving regular pulses from the intra-cavity pumping mechanism, which facilities a compact, accessible and robust pulse source at 2.1 μm.
