Optically pumped solid-state lasers with Nd:YAG may have to operate over a wide range of temperatures. We designed and fabricated a diode double end-pumped Nd:YAG laser for free space laser communication. Various laser beam parameters have been characterized for the same application. The temperature dependence of the effective stimulated emission cross section for 4F 3/2→4I11/2 transition and fractional thermal loading of Nd:YAG are determined using a planar resonator with two collimated and focused pump beams from fiber-array package laser diodes at 808nm. The pump power-induced thermal lensing is used to stabilize the cavity. The diode double end-pumped Nd:YAG laser possesses an extremely good beam profile that exactly matches the theoretical Gaussian intensity distribution up to a diode current of 30A. After that the ellipticity slightly increases, indicating deviation from the circular symmetry of beam, which may be due to the thermally induced birefringence of the Nd:YAG crystal offered to the polarized laser beam. The thermal lens focal length decreases with an increase in the absorbed pump power, similar to the case of a lamp pumped Nd:YAG laser and a diode pumped Nd:YVO4 laser. All the results indicate that the laser beam characteristics are useful for high data rate free space laser communication links. © 2008 Society of Photo-Optical Instrumentation Engineers.