The gain measurement was carried out with an atmospheric pressure cw CO2laser pumped by 4.2μm radiation emitted from a blackbody. The optical gain coefficient of 1.1× 10-4cm-1was obtained for the gas mixture of CO2: He=1:100. Theoretical calculations of optical pumping rate and small signal gain are presented.
An air exhausting laser window which consists of a small orifice, a window duct and an exhaust duct has been used to seal a low pressure simulated laser cavity and optically transmit a laser beam into the outside environment. The aerodynamic performance studies show that the purity of the cavity gas is maintained if a small quantity of the fresh laser gas is supplied into the cavity. The exhaust pump power is small compared to the total input to high power laser systems. It has been shown that in this type of aerodynamic window, the optical distortions are practically insignificant. These results clearly confirm the feasibility of the air exhausting laser window.
The aim of this investigation is to determine whether or not a quartz oscillator could be used to measure the energy of high-output lasers. A 2.0mm-diameter spot was irradiated on the crystal panel of a quartz oscillator using a 1.06μm glass laser beam with a 40μS pulse width. Under a few hundred laser irradiations with 130 mJ/pulse, the oscillation frequency increased about 10 Hz against 2 MHz. The relation between the increase in frequency and the laser output power was obtained. The results confirmed that a quartz oscillator could be utilized to measure the energy of high-output lasers.