Picosecond four-wave mixing in GaN epilayers

Summary form only given. Experiments were performed by picosecond four wave mixing on a 7 /spl mu/m-thick MOCVD-grown GaN epilayer using the second-harmonic of a modelocked, Q-switched Nd:YAG laser. In order to directly measure the total scattering efficiency, the boxcar geometry was used. The nonlinear refraction coefficient can then be determined from a relation.