| 摘要 |
PURPOSE:To remove a beat fault and to flatten diffraction efficiency by installing plural pieces of piezoelectric transducers having different operating center frequencies in one row along the advancing direction of a light beam on the plane intersecting orthogonally the light beam incident surface of an ultrasonic light deflecting medium. CONSTITUTION:Piezoelectric transducers 6-8 are installed on the plane intersecting orthogonally an ultrasonic light deflecting medium 5 and the surface of the medium 5 to which a light beam 10 is made incident. High-frequency outputs are respectively impressed from driving circuits 11-13 on the transducers 6-8. The diffraction angles of the light beam obtd. are respectively 0.8, 0.9 and 1.1 deg. when molybdate is used for the medium 5, lithium niobate for the elements 6-8 and an He-Ne laser beam for the beam 10 and when three waves 80, 90, 110MHz are used for the carrier frequencies of the circuits 6-8. The generation of a beat fault is thus eliminated and the same diffracting effect is obtd. for the respective diffraction angles of the three waves. |
