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 w
avelength of 351 nm and injected by a diode laser at 788.2 nm in the noncol
linear phase-matching case. Amplified and spontaneous parametric signals ar
ound 633 nm were measured in a photon-counting setup, at different powers o
f both the argon and the diode laser. This experiment is preliminary to the
absolute radiance measurement of a thermal source.