Multiphonon relaxation in laser materials and applications to the design of quantum electronic devices

An account is given of the results of a recent investigation of multiphonon orbit-lattice relaxation of excited states of rare-earth ions in crystals. The use of these results in the design of quantum electronic devices is discussed, using as examples the Nd³⁺laser transition and a 10.6-μ infrared quantum counter. A discussion is presented of the infrared limit of quantum electronic devices using these materials. Extension of these concepts to transition-metal ions in crystals is considered and a measurement of¹ to³ multiphonon decay in Al2O3: V³⁺is presented.