2μm Laser Based On An Electro-opticalq-switched Intracavity Ktp Optical Parametric Oscillator

摘要

An 2 μm pulse laser based on an intracavity optical parameter oscillator (OPO) pumped by an electro-optical Q-switched 1.064 μm laser is realized. A type-Ⅱ phase-matched (θ = 51.5°and ψ = 0) KTP crystal and a limiting diaphragm with a diameter of 4 mm were used. The parameters of the KTP-OPO tuning curves as a function of the phase matching angles were analyzed for the case of 1.064 μm laser pumping. Experiments based on single and double KTPs for walk-off compensation were performed. An output energy of 26 mJ in the 2 μm wavelength region was obtained with a pump-to-signal conversion efficiency of 26%. The center wavelengths of the signal and idle lights were 2165.4 and 2088.6 nm with a FWHM of 3.8 and 4 nm, respectively.