Parametric fluorescence in ADP and KDP excited by a 2573 a CW pump

Measurements of CW parametric fluorescence in ADP and KDP will be reported in which both signal and idler frequencies were in the visible region of the spectrum. The pump beam was at 2573 Å and was obtained from an internal SHG laser (1). Parametric fluorescence was observed over the range 4000 Å to 7000 Å in ADP and from 4400 Å to 6000 Å in KDP by turning the crystals over approximately 56°C from -11°C to +45°C. Phase-matching was at 90° to the optic axis and the pump power was 25 mwatts.