| 摘要 |
PURPOSE:To increase noise resistance and improve the S/N ratio by a constitution wherein a luminous energy corrsponding to the pressure acting on the path of propagation of an elastic surface wave is made to fall on a light-receiving element. CONSTITUTION:When a light is let to pass into a light transmission path 5 under the presence of the elastic surface wave generated by an electroacoustic transducer 3, it is diffracted and deflected by the elastic surface wave. When the strain is caused by the pressure acting on a region 6 of propagation, the elastic constant of the light transmission path 5 is changed by the strain and thus the velocity of the elastic surface wave, i.e. the wavelength thereof is changed. Corresponding to the change of pressure, the deflection angle of a diffracted light changes and thereby the luminous energy led out from a coupler 2B, a rod lens 1B and an output optical fiber 8B is changed. |
