OPTICAL-TO-MICROWAVE FREQUENCY CHAIN UTILIZING A 2-LASER-BASED OPTICAL PARAMETRIC OSCILLATOR NETWORK

A method for building an optical-to-microwave frequency chain and for measuring optical frequencies relative to the cesium primary frequency standard is described. Based on optical frequency division via parame tric oscillators, the concept is to generate two known ratios (1/2 and 4/9) of an optical calibration frequency f(1) whose frequency differe nce is measured relative to the cesium clock. The (1/2) ratio is obtai ned by either a 2:1 frequency division of f(1) or second-harmonic gene ration of (1/2) f(1). The (4/9) ratio of f(1) can be generated with a 3:1 frequency divider driven by a second laser at f(2) that is chosen to be near (2/3)f(1), which in turn is obtained with a f(1)-pumped 3:1 frequency divider. A set of auxiliary Optical Parametric Oscillators (OPOs) with outputs centered at (1/2) f(1) is used to facilitate the d ifference-frequency measurement between the two ratios. A practical co nfiguration utilizing a YAG and a Ti:Al2O3 laser and its application t o a number of precision measurements of interest are presented.