Abstract

Coherent connection of frequencies in a 3:1 ratio is now experiencing wide experimental effort, for several reasons. First, the generalized use of nonlinear frequency mixing in crystals, together with that of solid-state lasers, is opening new routes toward more compact and reliable frequency-synthesizing systems, for metrological or industrial applications. Also, as N. C. Wong recently discussed,¹ building a frequency chain that goes from the Cs clock up to visible frequencies could require only a few lasers, thanks to the combined use of 2:1 and 3:1 OPO frequency dividers.

© 1996 Optical Society of America