| 摘要 |
PURPOSE:To improve the resolution of frequency analysis, by increasing the deflection angle of guided light with two surface elastic waves. CONSTITUTION:A light beam L from a light source 21 becomes a parallel beam through a condensing diffraction grating 13 for an incident light beam. The beam is inputted into a light guide 12 and guided as guided light L1. A high frequency wave R, whose frequency is to be analyzed, is inputted into an amplifier 19. An AC voltage, whose frequency is equal to the high frequency wave R, is generated and applied to a pair of first and second slant-finger type chirp intersected comb electrodes 17 and 18. Then, first and second surface elastic waves 15 and 16 having the same frequency as the high frequency waves R are generated. The elastic waves are propagated in the direction intersecting the light path of the guided light L1. The guided light L1, which is deflected by the elastic wave 15, is deflected by the elastic wave 16 again. Therefore, the deflection angle can be increased in comparison with the case the guided light is diffracted and deflected only once with the surface elastic wave. Thus the resolution of the detection of the deflection angle becomes high, and the resolution in frequency analysis can be improved. |
