Improved acousto-optic modulators for CO2 heterodyne laser systems

Acoustic damping layers of indium on germanium acousto-optic modulators are found to reduce unwanted acoustically delayed modulations of transmitted CO2 laser beams by, typically, 10 dB for the first reflected pulse, the second reflected pulse becomes barely observable; subsequent reflections become unobservably small. A more sensitive monostatic laser radar is therefore obtainable.