Stimulated emission from neodymium-doped yttrium aluminum garnet crystals pumped with injection lasers

An investigation was made of the operation of a YAG:Nd³⁺ laser excited by pulse-injection semiconductor lasers emitting at wavelengths of 0.81 and 0.88 μ. The flat end of an active rod was pumped. The roomtemperature laser thresholds of rods of 1 mm diameter and 20 mm long and of 2 mm diameter and 20 mm long were 1X10^–4 and 3.7X10^–4 J, respectively. A study was made of the emission when the rate of pumping was twice the threshold value. The stimulated emission from the Nd³⁺ ions was of spiky nature: The duration of each spike did not exceed 1 μsec and the power carried by a spike could reach 100 mW.