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

 Zifu Wang, George R. Rossman, Geoffrey A. Blake

 Division of Geological and Planetary Sciences
California Institute of Technology Pasadena, CA 91125-2500, U.S.A.


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 beta-BaB2O4, 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 singlecrystal samples masked with pinholes of diameters 5-12.5 micrometers. We also discuss potential future improvements of microsampling OPO spectrometers.