A sealed-off strontium vapor laser

A sealed-off strontium-vapor laser for medical applications is examined. This is an integrated system that accommodates an excitation circuit, a laser cavity, and an active element. The active medium is excited by means of a modified Blumlein circuit. An unstable resonator of the telescopic type allows a near-diffraction-limited laser beam to be generated. Lasing is obtained in atomic strontium lines at lambda=2.06, 2.2, 2.69, 2.92, 3.011, and 6.45 mum and in ionic strontium lines at lambda = 1.033 and 1.091 mum. We have studied experimentally the behavior of spectral distribution of the output power at varying power delivered to the discharge. It is found that 95% of laser radiation is concentrated in the line at lambda=6.456 mum, which corresponds to a lasing power of similar to 2.5 W. Moreover, the time characteristics of lasing pulses are investigated. The radial inhomogeneity of the laser beam is examined. We have conducted lifetime testing of Sr-vapor active elements. The average output power exhibits a modest decrease (5%) within 300 h of a continuous operation. Notably, the pumping characteristics remain unchanged.