Demonstration of a diode-pumped metastable Ar laser.

Pulsed lasing from optically pumped rare gas metastable atoms (Ne, Ar, Kr, and Xe) has been demonstrated previously. The laser relies on a three-level scheme, which involves the (n+1)p5/2 and (n+1)p1/2 states from the np(5)(n+1)p electronic configuration and the metastable (n+1)s3/2 level of the np(5)(n+1)s configuration (Racah notation). Population inversions were achieved using relaxation from ((n+1)p5/2 to (n+1)p1/2 induced by collisions with helium or argon at pressures near 1 atm. Pulsed lasing was easily achieved using the high instantaneous pump intensities provided by a pulsed optical parametric oscillator excitation laser. In the present study we examine the potential for the development of a continuous wave (CW) optically pumped Ar laser. We report lasing of the 4p1/2→4s3/2 (912.547 nm) transition following CW diode laser excitation of the 4p5/2←4s3/2 line (811.754 nm). A pulsed discharge was used to generate Ar 4s3/2, and the time-resolved lasing kinetics provide insights concerning the radiative and collisional relaxation processes.