High-power, frequency-doubled all-polarization-maintaining fiber laser system at 925 nm

作者：Nan Zhang, Zhaoheng Liang, Wenlong Wang, Junpeng Wen, Yalong Liu, Xiaoming Wei, Zhongmin Yang · 发表于：Optics Letters · 年份：2024 · DOI：10.1364/ol.539956 · 被引用次数：7 · 研究领域：Advanced Fiber Laser Technologies、Advanced Fiber Optic Sensors、Photonic Crystal and Fiber Optics

We demonstrate a high-power 925-nm pulsed laser system based on a frequency-doubled, all-polarization-maintaining (PM) fiber laser source operating at 1.8 µm. The seed is a figure-9 mode-locked oscillator, which incorporates a nonlinear amplifying loop mirror. After power scaling and pulse compression, the 1.8-µm laser source can provide femtosecond pulses with a repetition rate of 31.3 MHz and an output power of 2.24 W. Through frequency doubling in a nonlinear crystal, the 925-nm laser delivers a pulse duration of 503 fs and an output power of 818 mW, which is the highest power provided by all-PM fiber laser systems at this wavelength, as far as we know. Furthermore, this 925-nm all-PM fiber laser is employed as the excitation light source for two-photon microscopy (TPM) and second-harmonic generation (SHG) microscopy.