OPTIMIZATION OF PHOTOINITIATED IMPULSE-ENHANCED ELECTRICALLY EXCITED CO2-LASER DISCHARGES BY ATTACHMENT CONTROL

Control of frequency and amplitude of the impulses used in photoinitia ted, impulse-enhanced, electrically excited laser pumping determines t he E/p value of the discharge. This occurs through the influence of th ese impulses on the processes of electron density decay and ion-electr on recombination and dissociative attachment. The degree of attachment can be controlled through the use of high-frequency excitation (f > 1 0 kHz), while the relative importance of ion-electron recombination in creases with increasing impulse potentials. The reduced electric field E/p can thus be varied by a factor of 3, while the anode fall potenti al V(a) can be reduced from 400 to 250 V. This technique appears amena ble to providing fine variation and control of the laser output power. Possible applications in materials processing are pulse shaping and r apid power modulation (superpulsing).