| 摘要 |
PURPOSE:To obtain an ultrasonic optical modulator without using optical signal input/ output means neither expensive acoustooptic materials by changing the voltage or the frequency of an electric signal supplied from an oscillator to a reed screen type electrode to obtain a modulated light as a diffracted light from an ultrasonic wave in a liquid. CONSTITUTION:An ultrasonic wave 24 is propagated in a liquid 30; and when light 22 is made incident on the inside of the liquid in this state, the light 22 is diffracted by the acoustic field in the liquid, and a diffracted pattern 44 is obtained form a window 28. This diffracted pattern 44 is changed in accordance with the voltage (applied voltage) or the frequency of the electric signal applied to a reed screen type electrode 14. That is, each peak value of the diffracted pattern 44 is changed, and a diffraction angle theta of the diffracted pattern is changed when the frequency is changed. For example, the output voltage of an oscillator 32 as a modulating signal is changed to detect electrically the variance of the intensity of the diffracted light of a certain order of the diffracted pattern 44 through a photodetector 36 and an amplifier 40. Thus, a modulated signal whose amplitude is changed in accordance with the variance of the output voltage of the oscillator 32 is obtained from an output terminal 42. |
