PURPOSE: To prevent a phenomenon where a part of the reflected light returns toward a light emitting part by having different routes for the light incident to an optical disk from a light source and the reflected light from the disk.
CONSTITUTION: The light beams radiated to a waveguide line 9 from a laser diode 1 are first turned parallel to each other by a collimator lens 11. These parallel beams cross the surface acoustic waves SAW which are generated from a comb-shaped electrode ultrasonic wave oscillator 13 provided on the line 9 and are then made incident to the SAW with a Bragg angle θ0 to the surface of the SAW. The Bragg diffraction condition sin θ1=λ/2nΛ1 is satisfied to a specific direction, where λ shows the wavelength of the laser light, Λ0 is the wavelength of SAW and (n) is the refractive index of the line 9 respectively. As a result, a laser beam 40 undergoes the Bragg diffraction and has a change of its traveling direction by 2θ0.
INOUE NAOHISA
MORI KAZUHIKO
MATANO MASAHARU
TAGUCHI ISAO
| JPS5348703A | 1978-05-02 |