Patent ID: 8175126
Filing Date: 2012-05-08
Classification: G01D,G01S,G02F,H01S

Abstract:
1. An opto-electronic swept-frequency laser system having a wide frequency range and precise control of the frequency of optical emission within the range, the system comprising: a semiconductor laser emitting in the optical spectrum, said laser including an injection current input and providing an output of controllable frequency in response thereto; an optical feedback circuit coupled to control the output of the semiconductor laser by varying the injection current input thereto; the feedback circuit including a signal divider receiving the laser output and providing a major power output signal and a fractional feedback signal therefrom; an interferometer receiving the feedback signal from the divider and providing an optical beat signal that varies in accordance with the laser output frequency; an optical mixer responsive to the optical beat signal for generating an RF beat signal in response to the optical beat signal; a reference oscillator providing an electronic reference signal; an electronic mixer receiving as one input the RF beat signal output from the optical mixer and the electronic reference signal as another input, to provide a mixed RF output signal; a circuit responsive to the electronic reference signal for providing a time-varying offset signal for optical frequency predistortion of the injection current to the laser in synchronism with the electronic reference signal, and an integrator circuit receiving both the RF output from the electronic mixer and the time varying offset signal, and having an output coupled to the injection current input of the semiconductor laser to provide precise control of the optical frequency thereof.