Аннотация:Infrared radiation (λ = 10.6 μ) was converted to visible radiation (λ = 0.689 μ) in a proustite crystal pumped by a krypton ion laser (λ = 0.647 μ). The conversion efficiency was determined for two interaction configurations, one of which was collinear and the other perpendicular. In the collinear interaction the power conversion efficiency was 2 10–6 for focused pump and signal radiations