Patent ID: 7286209
Filing Date: 2007-10-23
Classification: G01S,H01S

Abstract:
1. Apparatus for generating coherent optical radar signals, comprising: at least first and second laser sources each including a first laser operable to provide an optical beam of a relatively low frequency F each said laser source being operable to provide first and second output optical beams of relative frequencies F at least first and second waveform generators, each including a modulator and a mixer; each said first output optical beam of frequency F each said second output optical beam of frequency F a source of modulation signal for providing a modulation signal to said modulator of only said first waveform generator to generate a modulated F said modulated F said mixer of said first waveform generator being operable, as a result of mixing said optical beam of frequency F said mixer of said second waveform generator being operable to provide an output optical beam of a frequency which is the difference between its two input optical beams; at least one phase comparator having first and second inputs and first and second outputs; the modulated optical beam of said mixer of said first waveform generator being provided to said first input of said phase comparator; the optical beam of said mixer of said second waveform generator being provided to said second input of said phase comparator; a feedback device for providing a feedback signal to said modulator of said second waveform generator; said phase comparator being operable to provide an optical beam at said first output to said feedback device, which as a result, will generate said feedback signal to bring the phase of said output optical beam of said second waveform generator into synchronism with said modulated optical beam of said first waveform generator; said phase comparator being additionally operable to provide at said second output, an output coherent optical beam which is the sum of said optical beams provided at its first and second inputs when said optical beams are in synchronism.