Abstract

Optically pumped luminescent centers are now widely used as generators and detectors of high-frequency phonons in crystals. Monochromatic phonon generation and detection with such centers have for the first time been demonstrated in ruby by observing the R₁ and R₂ fluorescent intensities as a function of the pumping power and a magnetic field.¹ The optical techniques have made high-frequency phonons accessible to experiment, thus allowing important new information to be obtained. Here we present a new scheme of optical phonon spectroscopy which is inherently selective for near-zone-boundary phonons. As for the detection, the scheme employs, instead of a direct phonon-associated transition, second-order Raman transitions connecting two luminescent states. As an example we consider the case of ruby.

© 1984 Optical Society of America