Lin Chenhui, Zhao Hui, He Jiayi, Dai Shibo, Zhu Siqi, Yin Hao, Li Zhen, Chen Zhenqiang
Opt Express. 2024 Jan 29;32(3):4180-4188. doi: 10.1364/OE.514444.
We demonstrate the first ten-watt-level eye-safe intracavity crystalline Raman laser, to the best of our knowledge. The efficient high-power eye-safe Raman laser is intracavity-pumped by an acousto-optically Q-switched 1314 nm two-crystal Nd:YLF laser. Benefiting from the unique bi-axial properties of KGW crystal, two sets of eye-safe dual-wavelength Raman lasers operating at 1461, 1645 nm and 1490, 1721nm are achieved by rotating the Raman crystal. Under the launched pump power of 84.9 W and the repetition rate of 4 kHz, the maximum first-Stokes output powers of 7.9 W at 1461 nm and 8.2 W at 1490 nm are acquired with the second-Stokes output powers of 1.4 W at 1645 nm and 1.5 W at 1721nm, respectively, leading to the eye-safe dual-wavelength Raman output powers of up to 9.3 and 9.7 W. Meanwhile, the pulse durations at the wavelengths of 1461, 1490, 1645, 1721nm are determined to be 4.8, 5.5, 4.3, and 3.6 ns, respectively, which give rise to the peak powers approaching about 410, 370, 80, 100 kW. These Stokes emissions are found to be near diffraction limited with M < 1.6 across the entire output power range.
据我们所知，我们展示了第一台十瓦级人眼安全腔内晶体拉曼激光器。高效高功率人眼安全拉曼激光器由声光调Q的1314 nm双晶体Nd:YLF激光器进行腔内泵浦。受益于KGW晶体独特的双轴特性，通过旋转拉曼晶体实现了两组分别工作在1461、1645 nm和1490、1721 nm的人眼安全双波长拉曼激光器。在84.9 W的泵浦功率和4 kHz的重复频率下，在1461 nm处获得了7.9 W的最大一阶斯托克斯输出功率，在1490 nm处获得了8.2 W的最大一阶斯托克斯输出功率，在1645 nm处的二阶斯托克斯输出功率为1.4 W，在1721 nm处的二阶斯托克斯输出功率为1.5 W，从而实现了高达9.3 W和9.7 W的人眼安全双波长拉曼输出功率。同时，在1461、1490、1645、1721 nm波长处的脉冲宽度分别确定为4.8、5.5、4.3和3.6 ns，其峰值功率分别约为410、370、80、100 kW。发现这些斯托克斯发射在整个输出功率范围内接近衍射极限，M<1.6。
