A compact, highly stable CW CO2 laser without Brewster windows

We describe an open resonator, quasi sealed-off, 70cm cavity length CO2 laser with very high stability of power and frequency, which lases on 96 lines from 9R42 (2W) to 10P52 (5W) with a power of >11W on 9R20, 9P20, 10R20 and 10P20, plus on 18 hotband lines with approximate to 2W. This laser was used successfully to pump an FIR ring laser [1] enabling an FIR power stability of Delta P/P approximate to 10(-4) by use of a simple PI control loop, thus demonstrating its superb frequency stability.