Laser Ranging Technology for Space to Space Applications. Volume 2: High Stability CO2-Laser for Range Rate Finder Development of Critical Technologies

摘要

Frequency stabilization of space applications CO2 lasers was studied. A laboratory model of a frequency stabilized CO2 laser, consisting of a frequency tunable CO2 laser, a frequency reference gas cell, optical means to polarize, expand and couple-out the beam, a beam detector, and frequency control electronics to generate an appropriate error signal to the CO2 laser was developed. Reference gas absorption investigations, laser noise and ripple studies and frequency stabilization experiments were carried out. A short term frequency stability (1 to 10 sec) of - 10 billion limited by laser ripple and by the available measurement method is detected. The long term frequency stability (1 hr) is - 100 million. A concept for a compact, spaceborne CO2 laser system and of suitable frequency stability and linewidth measurement methods is elaborated.