Pickup for optical digital disk

Abstract

Abstract 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 theta0 to the surface of the SAW. The Bragg diffraction condition sin theta1=lambda/2nLAMBDA1 is satisfied to a specific direction, where lambda shows the wavelength of the laser light, LAMBDA0 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 2theta0.

Inventors

• 👤 Maki Yamashita
• 👤 山下　牧
• 👤 Naohisa Inoue
• 👤 直久 井上
• 👤 Kazuhiko Mori
• 👤 和彦 森
• 👤 Masaharu Matano
• 👤 俣野　正治
• 👤 Isao Taguchi
• 👤 功 田口

Bibliographic Details