Accuracy improvement in mid-infrared spectral analysis based on a pump-heralded optical parametric oscillator

An approach to improve the accuracy of coherent mid-infrared (MIR) spectral analysis is proposed, which minimizes the impact of the inherent source fluctuation. A simple pulsed-laser pumped BaGa 4 Se 7 optical parametric oscillator (OPO) is employed as the tunable light source with a wavelength range of 3.13–6.17 µm. The time series of pulse energies monitored at different positions are investigated, especially the residual pump. It is observed that the coefficient of determination R 2 of the linear regression between the MIR output and pump depletion reaches 86.88%. This remarkable relationship is favorable to reconstruct the reference spectrum of the OPO output with small error. Finally, synchronous spectral analysis with high accuracy is demonstrated based on this pump-heralded OPO.