| 摘要 |
PURPOSE:To obtain uniform diffraction efficiency by allowing two optical adjacent transducers to nearly satisfy specific conditions. CONSTITUTION:An SAW 7 excited by an IDT 4 operates as a moving diffraction grating for incident light 2; and part of the incident light 2 is Bragg-diffracted into diffracted light 8 and the remainder is transmitted as it is to obtain undiffracted light 9. The diffracted light 8 is separated from the undiffracted light 9 and used for signal processing, recording, etc. In this case, two optical adjacent transducers nearly satisfy conditions shown by equations. Consequently, a transducer array which have uniform diffraction efficiency over the entire operation frequency band is obtained.
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