92% pump depletion in a CW one-pump fiber OPA

Summary form only given. Devices based on the nonlinear optical susceptibilities /spl chi//sup (2)/ or /spl chi//sup (3)/ can be used for performing important functions such as amplification or wavelength conversion. Typically one uses a strong pump, and injects a weaker signal into the device, thereby generating at the output an amplified signal, and a strong idler. In a well-designed device, most of the pump energy can be transferred to the signal and idler. Hence a measure of the efficiency of such a device is obtained by the amount of pump depletion obtained. /spl chi//sup (2)/-based devices have been under development for many years, and pump depletion in excess of 90% is routinely obtained with either pulsed or CW devices. /spl chi//sup (3)/-based devices are not as advanced, and to our knowledge large pump depletion has not been reported for /spl chi//sup (3)/ OPAs. Here we report 92% pump depletion, with a 200 mW CW pump at 1560 nm in an 11 km-long dispersion-shifted fiber (DSF).