Correlated-fields high-resolution spectroscopy

We have improved the correlated-fields spectroscopy in order to extend the available offset frequency-range up to ± 40 MHz by compensating the frequency-dependent Bragg diffraction of acousto-optic frequency shifter. This jitter-free technique has been applied to the studies of two-beam coupling in Nd:glass and Ti:S, Rayleigh wing scattering in liquid crystal, and hole-burning spectroscopy in Tm3+:YAG. Spectral resolution of less than 10 kHz has been obtained in these first two subjects, and the hole-burning spectrum with line width less than 150 kHz has been clearly resolved despite the use of nonstabilized laser sources.