Superluminescence emitted by YAG:Nd3+ crystals and stimulated emission due to weak transitions

The luminescence spectra of YAG:Nd³⁺ crystals were investigated by express spectroscopy. The dependences of the luminescence intensity on the pump energy were obtained and the Superluminescence energy thresholds were determined at T = 300 and 77°K. It was concluded that stimulated emission was possible due to weak transitions in YAG:Nd³⁺ crystals and the output energy could become saturated. This was supported by single-frequency and multifrequency stimulated emission due to weak transitions in the λ= 1.06 μ region inside a dispersive resonator.