In order to estimate deleterious effects caused by heating in continuous-wave end-pumped solid-state lasers, the heat equation has been solved for an axially heated cylinder with a thermally conductive boundary at the periphery. Steady-state thermal profiles are developed using both a full numerical solution and an analytic approximation which assumes only radial heat flow. The analytic solution, which is in good agreement with the numerical solution, is utilized to obtain an expression for the thermal focusing due to temperature-induced refractive index changes. For Nd:YAG, 1 W of pump power deposited as heat is predicted to cause a thermal focusing length comparable to the cavity length of a typical diode end-pumped laser.

We report on the first diode-laser (nominal 200-mW 10-stripe laser diode) end-pump lasing of Nd:YVO4. The lowest threshold (30 mW) and highest output power (120 mW) were observed from the Nd:YVO4 laser as compared to a similar Nd:YAG laser. Over 50% optical slope efficiency was obtained, the highest yet reported for diode pumping. This device performed at a 10% overall efficiency. Measurements over a 21-nm range show the advantages of the Nd:YVO4 pump absorption band.

The stimulated-emission cross sections at 1064 4I Il/2 ) and 1342 nm (4F3/2-;4I13/2) in Nd : YVO. were determined by measurement of laser thresholds as a fUnction of output mirror reflectivity. Small samples of Nd: YV0 4 and Nd: YAG were end pumped at room temperature with a cw 514.5-nm argon ion laser in an almost identical geometrical arrangement which permitted comparative values to be obtained. Assuming that the pumping quantum efficiency of Nd: YVO is similar to that of Nd: Y AG, the stimulatedemission cross sections obtained for the 1064-and 1342-nm transitions were respectively 12X 10-19 and 6.0X 10-19 cm 2 • PACS numbers: 42.55.Rz

The stimulated emission cross section of Nd:YAG (yttrium aluminum garnet) (4F3/2→4I11/2) was compared to the known cross section of Nd:ED-2 glass at 1060 nm. Small samples of Nd:YAG and ED-2 glass were end pumped with a chopped cw 514.5-nm argon-ion laser in an identical geometrical arrangement. The stimulated emission cross section obtained for Nd:YAG at 1064 nm was found to be 7.6 ×10−19 cm.

Continuous-wave plane-polarized outputs of 1 W at 1.06 μ and 0.35 W at 1.34 μ were obtained by end pumping small samples of Nd : YVO4 with an argon-ion laser. Slope efficiencies and material losses were determined. At 1.06 and 1.34 μ, Nd : YVO4 lasers can substantially outperform Nd : YAG lasers. Self-Q-switched operation of Nd : YVO4 at both wavelengths was obtained by resonator misalignment.