Operational Characteristics Of A Cw Nd - Cawo Laser In Range Of Dry Ice To Room Temperature

Experiments with continuous operation of Nd:CaWO4 lasers at liquid nitrogen and room temperature were reported previously [ L. F. Johnson G. D. Boyd K. Nassau R. R. Soden , Phys. Rev.126, 1406 ( 1962)]. This paper presents the operational characteristics of a continuous-wave Nd :CawO4 laser in the range of dry ice to room temperature. The experimental results are compared with the predicted equations for power output and threshold power. We have found that output power is a linear function of absorbed pump power as predicted from the rate equations for a four-level laser medium. The threshold equation agrees qualitatively with the experimental results in that it decreases with decreasing temperature due to the consequent narrowing of the fluorescent line-width. We have used the threshold condition to indicate the quantities that must be monitored to optimize the crystal preparation and growth conditions. Continuous-wave operation has been obtained with an ac and dc pump lamp.