Full-beam asynchronous GaAs laser heterodyne

A semiconductor laser optical mixer that generates intensity-modulated light at gigahertz frequencies is described. Two independent or "asynchronous" GaAs lasers serve as sources. A novel method for wavefront alignment and source optical isolation has allowed "full-beam" mixing. Heterodyne difference frequencies as large as 10.2 GHz have been generated from both a Si-APD and a GaAs-EAP. The frequency-response characterization of both photodetectors is presented.