Absolute instrument spectral response measurements using angle-resolved parametric fluorescence

The broadband parametric fluorescence from a nonlinear crystal can be used as a compact primary source instead of a blackbody for absolute measurements of instrument spectral efficiency. We describe such a setup for measuring the instrument spectral response function in the wavelength range from 450 to 1000 nm. We perform angle-resolved imaging spectroscopy of conical parametric fluorescence in a beta-barium borate crystal pumped by a 405-nm diode laser. The experimental angle-resolved spectra and the generation efficiency of parametric down-conversion agree with a plane-wave theoretical analysis. (C) 2013 Optical Society of America