| 摘要 |
PURPOSE:To obtain a stable frequency characteristic at a low cost by dividing electrodes provided to a piezo-electric element and mounting surface in the direction connecting the light incident and exit faces provided to a tellurium dioxide crystal and connecting the piezo-electric element electrically in series thereto. CONSTITUTION:The piezo-electric element 2 is mounted to the tellurium dioxide 1 and the electrodes 3, 4 are formed over the entire surface or part thereof by a vapor deposition method, etc. The electrodes are connected to each other by lead wires 5a-5c. A high-frequency electric signal of several tens - several hundreds MHz, when impressed between the lead wires 5a and 5c, is converted to an ultrasonic wave A which propagates in the crystal and is absorbed to an acoustical absorbent 8. Incident light I is emitted after said light is divided to non-diffracted light I0 which is transmitted light and diffracted light I1 when said incident light is entered from a specified direction. The piezo-electric element is mounted near a ridge 7 so that the shape and size of the tellurium dioxide crystal are made into a required min. size. A division point 6 is divided in this state by means such as scribing and thereafter the lead wires 5a-5c are connected thereto.
|
