On-resonant phase-conjugate reflection and amplification at 10.6 µm in inverted CO2

A simple and straightforward technique is developed for obtaining high-reflectivity phase conjugation through the use of the nonlinear properties of the laser gain medium itself. The experimental setup consists of a hybrid high pressure-low pressure TEA CO2 laser operating with a 10-m radius-of-curvature 35% reflecting mirror and a flat 10% reflecting mirror. The high reflectivity arises from the combination of resonant light-by-light scattering and amplification within the active gain medium of the TEA CO2 laser oscillator cavity. The paper outlines the first reported demonstration at 10.6 microns of both phase-conjugate reflection in an amplifying medium and effective phase-conjugate reflectivity in excess of unity. This process should work in most laser systems.