High-efficiency degenerate four-wave mixing of 1.06-microm radiation in silicon

We report detailed experimental results on degenerate four-wave mixing of 1.06-microm laser radiation in silicon. Using ~100-mJ pump pulses of 15-nsec duration from a Q-switched Nd:YAG laser at intensities of ~6.8 MW/cm(2), we obtained an energy conversion of over 150% for the probe-to-signal reflection.