Parametric amplification for radiance measurements

This paper presents the first results of parametric amplification obtained at the Istituto Elettrotecnico Nazionale G. Ferraris (IEN) at a wavelength of 633.5 nm in a crystal of lithium iodate, pumped by an argon laser at a wavelength of 351 nm and injected by a diode laser at 788.2 nm in the noncollinear phase-matching case. Amplified and spontaneous parametric signals around 633 nm were measured in a photon-counting setup, at different powers of both the argon and the diode laser. This experiment is preliminary to the absolute radiance measurement of a thermal source.