Thermal transient effects in silicate and phosphate rods pumped in pseudoelliptic close-coupled cavities

This paper presents the experimental results of a study on the thermal effects due to pulsed optical pumping in ED2 Nd glass rods, cladded with samarium glass, and in Q88 Nd phosphate glass laser rods. A pseudo-elliptic close-coupled pumping cavity, very efficient and simple to be made has been used; this entails two types of rod deformations which in turn are responsible of two optical effects: a focusing effect and a prismatic effect. The time evolution of these effects under single shot condition and at low repetition rate (1 pulse every 5 s) is described. At single shot the behaviour is opposite to that previously reported in the literature.