DIFFERENCE-FREQUENCY-GENERATION AND SUM-FREQUENCY GENERATION NEAR THEBAND-GAP OF ZINCBLENDE CRYSTALS

We present recent experimental results of difference-frequency generat ion (DFG) and sum-frequency generation (SFG) from zincblende materials . We measure the radiation field of difference-frequency generation an d the radiation intensity of sum-frequency generation versus crystallo graphic orientation and fundamental photon energy. The simultaneous me asurement of the angular dependence of polarized DFG and SFG is well c haracterized by the bulk second-order nonlinearity calculation. Pronou nced resonant behaviors near the GaAs band gap for both radiations (DF G and SFG) are compared.