Abstract

A new optical standard may come from advances in laser cooling and trapping of atoms. To evaluate whether these systems would provide a suitable standard, they must be linked with the microwave standards, most conveniently by means of the 3.39-μm methane-stabilized He-Ne laser. Various interesting transitions are only terahertz away from harmonics of 3.39 μm, and therefore a method for measuring these small differences to high accuracy is required. Such a device for this purpose is an optical comb generator. Such a system is devised of an electro-optic modulator in an optical cavity. The cavity is designed to be resonant not only with the carrier frequency but also with the modulated sidebands produced.^1,2

© 1995 Optical Society of America