OPTICAL-PHASE CONJUGATION REFLECTIVITY AND FIDELITY IN CS2 BY PICOSECOND PULSE 4 WAVE MIXING

We have performed experimental studies designed to elucidate the parameters which limit the efficiency and fidelity of optical phase conjugate reflection of picosecond laser pulses in transparent Kerr media. The experimental data show that at low pulse energies, the reflectivity follows the expected square dependence on the pulse energies. However, it falls below the square at high energies even though, at these high energies, a phase conjugation efficiency of 300% was observed. We observed a rather strong dependence of the reflectivity on the ratio of pump to probe pulse energy. The quality of phase conjugation decreased at very high pump energies, but could under some conditions be improved by focusing the probe beam into the interaction region. Of the several mechanisms responsible for the decrease in efficiency and fidelity, we find that the predominant ones are pump depletion, small scale self-focusing, and dephasing owing to a difference in energy of the two pump pulses.

OPTICAL-PHASE CONJUGATION REFLECTIVITY AND FIDELITY IN CS2 BY PICOSECOND PULSE 4 WAVE MIXING Academic Article