Optical Hole-Burning and Ground State Energy Transfer in Ruby

A recent application of homogeneous linewidth laser spectroscopy of optical solids is in energy transfer studies[1,2]. This paper describes a high resolution hole-burning study of the R1 line in ruby giving information on the energy transfer mechanism which determines the saturated lineshape. As is well known, the zero phonon R1 lines in ruby at liquid helium temperatures are inhomogeneously broadened due to crystal defects. When the 4A2(±1/2;f)→Ē transition (R1(1/2) hereafter) is saturated by a narrowband laser, the result shown in Figure 1 occurs[3].