Laser range and range rate finder. Study and development of critical technologies. Volume 2: CO2 laser for range rate measurement

Breadboard studies of CO2 optical Doppler radar subunits for spaceborne range measurement, target acquisition and tracking are reported. Laser oscillator, stabilization gas absorption cell, and optical stabilization loop concepts are discussed. Test results show that the oscillator and the optical elements must be improved before stabilization experiments with the gas cell can begin. The oscillator must be adapted to operation without water and gas-flow, and suitable grating must be used as end mirror. The optical isolation between laser and gas cell must be improved, for instance by inserting the acoustooptic modulator and by using polarization independent beam folding mirrors. Anodized aluminum pieces in the SF6 cell must be reworked with respect to the AL2O3 layer.