CO2regenerative ring laser amplifiers

The concept and operational charcteristics of a compact regenerative ring CO2laser power amplifier for frequency-stable operation are presented. Regenerative amplifier operation is explored in two distinct regions: (1) the region of unconditional stability where the amplifier gain is below oscillation threshold and (2) the region of conditional stability where self-oscillation can occur. Experimental techniques and results for output power levels up to 50 watts are presented. It is shown that saturation effects play a dominant role in the phase characteristics, the output power, and the bandwidth of the regenerative ring amplifiers. Measured amplifier static and dynamic bandwidth characteristics are compared with those derived from the laser and cavity parameters. The influence of these parameters on the amplifier frequency-locking characteristics are discussed.