The most longwave OPO pumped by a 1-/spl mu/m laser

Summary form only given.Chalcopyrite AgGaS/sub 2/ (AGS) crystal transmits light between 0.5 and 12 /spl mu/m, has high nonlinear-optical coefficient (d/sub 36/=12 pm/V) and is one of the few crystals which can be pumped by 1-/spl mu/m lasers-to get phase-matched down conversion into the /spl lambda/>5 /spl mu/m region. We demonstrate a 1.06-/spl mu/m pumped AGS OPO, with a broad tuning range of 3.9 to 11.3 /spl mu/m, high conversion efficiency, narrow linewidth and extremely low pumping thresholds.