Abstract

The spin mixing processes of optically pumped F center are specified by the spin mixing parameters ε's which represent the probability for the spin to be flipped in the optical cycle. One of the main aim of this talk is to estimate the mixing parameter ε_rl in the non-radiative transition (NRT) process as a function of pumping photon energy E_ph. The spin mixing is caused by the spin orbit interaction in the optical cycle.¹⁾ The mixing parameter in the unrelaxed excited state (URES) denoted as ε₊ and ε₋ are dependent on the spin quantum number of ±(1/2) of the ground state.²⁾ ε₀=(1/2)(ε₊+ε₋) and δε =(ε₋−ε₊) are used for convenience. Now, the spin-orbit interaction constant λ in the relaxed excited state (RES) was found to be small of less than one hundredth of λ value in the URES.³⁾ The calculated mixing parameter in the RES was also found to be negligibly small.⁴⁾ This evidence implies that, during the NRT process from the URES to the RES, the pumped F electron should pass down many sorts of multi-phonon levels characterized by λ values decreased gradually. Thus, the spin mixing parameter ε_rl cannot be neglected in the argument of the spin mixing processes in the cycle.

© 1984 Optical Society of America