Optical chopper based mechanically Q-switched ∼3 μm Er:YAP single-crystal laser

Abstract We developed a compact and low-cost diode-pumped ∼3 μ m mechanically Q-switched Er:YAP laser with high-power using an optical chopper. At 2.4 W pumping and 7 kHz modulation frequency, a stable single-pulse repetitively Q-switched laser with a wavelength of 2.796 μ m has been observed. We recorded the pulse duration, the peak power, and the pulse energy of 264 ns, 22 W, and 5.9 μ J, respectively. As increasing pumping power to 7.4 W at a frequency of 10 kHz, the lasing wavelength shifted to 2.921 μ m and a stable multiple-pulse laser was observed. The pulse with 75 ns duration and 34 μ J energy has been observed, corresponding to a peak power of 456 W. The peak power and the pulse energy are the highest value ever reported for an actively Q-switched mid-infrared (IR) Er:YAP laser. Thus, this laser has the potential to be utilized for industrial and science fields as high-power mid-IR light source.