Abstract

Interesting classes of solid state hosts for diode pumped lasers or for short pulse emission could be those with broad spectral bands. Although rare earth ions in glasses satisfy this condition, their use in diode pumped lasers is limited by the small stimulated emission cross section and thermal conductivity. Therefore, a crystal that fulfils all these three requirements is expected to give better performances. These characteristics could be satisfied by crystals with disordered structure such as calcium niobium gallium garnet Ca₃Nb₁₆₈₇₅ Ga₃₁₈₇O₁₂ (CNGG) and calcium lithium niobium gallium garnet Ca₃Nb₁₇₇₅ Ga₂₉₅ li₀₂₇₅ O₁₂ (CLNGG). These crystals have several advantages compared with ordered garnet crystals, such as YAG: low melting point (smaller than 1500°C), broad absorption and emissmn bands, targer doping level with ions such as Nd³⁺, better thermal properties than glasses. Though User emtaston was reported for Nd³⁺ in CNGG and CLNGG the growth conditions for homogeneous crystals or fibres, the spectroscopic characteristics, the nature of nonequivalent centers, and the energy transfer peculiarities are still problems to investigate.

© 2000 IEEE