Doubly Q-switched single longitudinal mode Nd:YAG laser with electro-optical modulator and Cr4＋:YAG

• Published in: Optics communications 2020-05, Vol.463, p.125500, Article 125500
• Main Authors: Jin, Duo, Bai, Zhenxu, Wang, Qingzheng, Chen, Yifu, Liu, Zhaohong, Fan, Rong, Qi, Yaoyao, Ding, Jie, Yang, Xuezong, Wang, Yulei, Lu, Zhiwei
• Format: Article
• Language: English
• Subjects: Doubly Q-switched; Resonant reflector; Single-longitudinal-mode; Symmetric pulses; Twisted-mode cavity
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2020.125500

An electro-optical modulator (EOM) and Cr4＋:YAG saturable-absorber-based doubly Q-switched Nd:YAG laser at 1.06μm with single-longitudinal-mode (SLM) output was demonstrated. The spatial-hole-burning suppression and cavity axial-mode selection were provided by a twisted-mode technique and resonant-reflector-mediated SLM operation. The Cr4＋:YAG initial transmittance (T0) affected the pulse profile, pulse energy, and laser spectra, which were analyzed theoretically and experimentally. Consequently, the laser output obtained an SLM rate of 96.2% with a symmetry factor of 0.64 when T0 was 6.2%. The results indicate that symmetric and SLM laser pulse can be obtained in a double Q-switched laser by adjusting the cavity loss according to T0. Compared with a solely Q-switched laser, the double Q-switches of EOM and Cr4＋:YAG provide a practical route toward the generation of a symmetric temporal profile and SLM operation. •The SLM operation of doubly Q-switched Nd: YAG laser was studied.•The symmetry factor γ = 1.05 for double Q-switching was obtained.•This method has wide prospects in the fields of solid-state lasers.