ABSTRACT
In the present system, two 50-mm-long PPLN crystals (Crystal Technology, Palo Alto, CA) with an aperture of 11.5 mm x 0.5 mm are used as the active medium. Each crystal contains eight poled regions with different periodicities. One crystal's periodicities range from 28.5 to 29.9 |nm, and of the other crystal from 30.0 to 31.2 |um. When operating at a crystal temperature of 148°C, these periods collectively allow tuning of the idler from 2720 to 3702 cm"1. The crystals are mounted in a stacked fashion within a temperature-stabilized copper oven that is attached to a vertical translation stage. Each crystal is tuned by selecting a period using the vertical motion of the stage; horizontal motion of the oven is used to select between the two crystals.
