Optical head device

Abstract

Abstract PURPOSE:To form an effective spot light on a disc while excluding aberration without scattering to an incident light by dividing a return light from a light collection grating coupler into two at a prescribed sharp angle by means of a beam splitter so as to send the result to a photodetector. CONSTITUTION:The titled device consists of a semiconductor laser 4 injecting a laser beam to a dielectric thin film conductive path layer 3 on the surface of a base 1, the light collection grating coupler 6 formed on the layer 3 as unequal interval curve groups and converging a laser light into one point light collection spot 14 on a dielectric thin film disc 8, photodetectors 10, 10 formed while being imbedded to the base 1, and the beam splitter 5 formed between the semiconductor laser 4 and the light collection grating coupler 6 and converging the light while dividing symmetrically into two at an angle of 30 deg. each with respect to the center optical axis in relation to the progressing direction of a reflected light from the disc 8 obtained by the coupler 6. Thus, the reflected light from the disc 8 converged by the beam splitter 5 is received by the photodetectors 10, 10 and converted into an electric signal.

Inventors

• 👤 Keizo Kono
• 👤 河野　慶三
• 👤 Natsuo Tsubouchi
• 👤 坪内　夏朗
• 👤 Hiroshi Nishihara
• 👤 西原　浩
• 👤 Toshiaki Suhara
• 👤 敏明 栖原

Bibliographic Details