| 摘要 |
PURPOSE:To stabilize characteristics by providing a means of detecting elastic waves opposite to an elastic wave transducer and controlling the temp. of an optical deflector in accordance with the output thereof. CONSTITUTION:Parallel luminous fluxes 6 of lasers are passed through a prism coupler 5 and are conducted as a luminous flux 7 into a waveguide 4, where it is deflected by the diffraction effect generated by the ultrasonic waves 10 excited by a comb toothlike electrode 8. Said deflected luminous flux is condensed by a thin film lens 12 in such a way as to form a luminescence spot 14 on the end face 13 of the waveguide. At this time, ultrasonic waves are generated in the electrode 8 by utilizing the flyback time of the luminous flux 11, and these are detected by th comb toothlike electrode 9 provided opposite to said electrode 8, whereby the velocity of the ultrasonic waves is measured. In accordance with the measured quantity thereof, an electrothermal transducer 1 consisting of a Peltier element, etc., is operated whereby the degradation in characteristics owing to the change in temp. is prevented. |
