High peak power passive Q-switched widely tunable Tm:YAP laser

This paper presents a novel, widely tunable, passively Q-switched Tm:YAP laser operating at high peak power in the 2-micron spectral range. While widely tunable lasers typically operate in continuous wave (CW) mode, and customary high peak power designs rely on active Q-switching methods, our innovative design combines both features in an all-passive configuration. The continuous tunability spectrum spans 41 nm, from 1911 nm to 1952 nm. Wavelength tunability was achieved using a 25μm thick YAG etalon. A Cr:ZnS saturable absorber is used for passive Q-switching, achieving a maximal repetition rate of 3 kHz, maximal energy per pulse of 1.42 mJ, and a very high maximum peak power of 54 kW. Additionally, a detailed theoretical analysis of the energy dependency on the wavelength is discussed. Such laser properties, especially implemented in an all-passive configuration, have great application prospects in many fields. •This paper presents a novel, widely tunable, passively Q-switched Tm:YAP laser operating at high peak power in the 2-micron spectral range. Simple, low volume and low cost tunable lasers are of continuous interest to the Laser community, especially in the SWIR spectral range, due to the enormous potential for application and the lack of high peak power laser sources.•While widely tunable lasers typically operate in continuous wave mode, customary high peak power designs are rare and rely on active Q-switching methods exhibiting very limited power output. The innovation lies in combining both features in an all-passive configuration, eliminating the need for amplification.•41 nm of continuous tunability between 1911–1952 nm is demonstrated, using a 25 μm thick YAG etalon with a Cr:ZnS saturable absorber achieving a maximal repetition rate of 3 KHz, maximal energy/pulse of 1.42 mJ, and a very high maximum peak power of 54 kW.•Such laser properties, especially implemented in an all-passive configuration, have great application prospects in many fields such as atmospheric sensing, material processing, microsurgery and scientific applications.•A detailed theoretical analysis of the energy/pulse dependency on the wavelength is discussed as well, contributing to further understanding the dynamics of tunable lasers.