A New Microsampling Visible-Infrared Spectrometer Based on Optical Parametric Oscillator Technology

This article describes the development of a new spectrometer based on tunable optical parametric oscillators (OPOs). Pumped at 355 or 532 nm, the OPOs, based on type II phase matching in β-BaB_2O_4, cover the wavelength range from 410 to 3200 nm. To test the feasibility of characterizing extremely small samples, we conducted absorption spectral measurements in the near-IR wavelength range on several single crystal samples masked with pinholes of diameters 5-12.5 µm. We also discuss potential future improvements of microsampling OPO spectrometers.