1653 nm optical parametric amplifier and its application in remote sensing of CH₄

Based on magnesium oxide-doped periodically poled lithium niobate (MgO:PPLN) crystal, a second-level optical parametric amplifier (OPA) with continuous-wave(CW) laser injection was studied. Pumped by a 10 kHz, 1064 nm, 6 W(the maximum average output power) high-frequency pulse laser and seeded with a low power distributed feedback (DFB) diode CW laser, the OPA obtained a signal at 1652.3 nm and 119 ℃ with the crystal polarization cycle of 31.02 m. The maximum average power of the signal was 125 mW with the quantum conversion efficiency of 7.47%. By changing the wavelength of the seed laser, the output wavelength could be adjusted in the nanometer range. When the signal light passed through the methane gas pool at the distance of 10 m, the spectral intensity decreased obviously, and the feasibility of the signal light in the remote sensing of methane was preliminarily verified. Compared with direct detection by the seed light, the intensity of signal light is much higher, and it has great advantages in detection range and sensitivity.