physica status solidi (b)
Stimulated Echo and Vibrational Dynamics
V. Hizhnyakov
Abstract
Abstract Stimulated echo (SE), excited in an inhomogeneously‐broadened vibronic absorption band of impurity centres by three successive pulses, is considered. SE for a small delay time t2 of the second pulse, comparable with the characteristic time of vibrational relaxation, is essentially determined by the vibrational dynamics of the excited centres. The processes of a absorption and amplification of the third exciting pulse are differently modulated by vibrations, giving different contributions to the amplitude of SE. The absorption contribution is described by the function A(t3, t2, t2), while that of the amplification by A(t2, t3, t3), where A(μ, τ, τ′), is the correlation function of the resonance secondary emission of centres. For very short t2 and t3, i. e. essentially smaller than the periods of vibrations, the latter can play a role of inhomogeneity in the system, allowing one to observe the SE on homogeneous systems, such as ionic crystals with colour centres (F‐centres).