A combined optical parametric oscillator (OPO) with continuous tuning of the radiation wavelength in the spectral range 2.5-10.8 μm, optically pumped with the radiation from a Q-switched Nd:YLF laser (1.053 μm), is developed and tested. The oscillation is provided by an OPO1 based on a MgO:PPLN 'fan-out' structure in the spectral region 2.5-4.5 μm and by an OPO2 based on HgGa2S4 nonlinear crystals in the spectral region 4.18-10.8 μm, respectively. The angles of phase matching are measured for the HgGa2S4 crystals in the spectral range 4.18-10.8 μm for the type II conversion (eo-e), which virtually coincide with the calculated ones. The experimental absorption spectra of a gas mixture in the range 2.5-10.8 μm obtained using a gas-filled sealed-off photoacoustic cell are presented.
- HgGaS nonlinear crystal
- MgO : PPLN 'fan-out' structure
- Optical parametric oscillator
- optical parametric oscillator
- HgGa2S4 nonlinear crystal