Ten-watt-level all-solid-state eye-safe intracavity Raman laser

Abstract

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 M2 < 1.6 across the entire output power range.