Optical Detection of the Hyperfine Interaction of the F Center in KCl in the Absence of Resonant Oscillating Fields

Abstract

By adopting Mezger and Jaccard's method, we have optically determined the isotropic and anisotropic hyperfine (hf) parameters for the K nuclei at the fifth shell in the ground state of the F center in KCl at 4.2 K. We have found three additional facts: (1) the hf signal intensity is decreased with an increase of the frequency of the modulation field superimposed on the static magnetic field; (2) the spin-lattice relaxation time in the relaxed excited state is an important factor for the occurrence of the hf signal; (3) the hf signal intensity is independent of the excitation power, P , in the low magnetic field range. However, it is reduced with an increase in P of the high-power pulse laser.