Exchange Effects in Optical Detection ESR and Dynamics of the Optical Pumping Cycle of F-Centers in KCl

Abstract

ESR spectra of F-center pairs or clusters in which each electron is either in the ground state or in the relaxed excited state have been observed at 34 GHz and 1.6K in KCl using the optical detection technique. They are analyzed in terms of an appropriate spin-Hamiltonian including the exchange interaction between the electron spins. Also, the change in the intensity of the F-center luminescence due to ESR is calculated by considering an optical pumping cycle in the presence of external static- and microwave- magnetic field. The result is reasonably compared with the experimental results.