JPS57169935A - Photodetector using semiconductor laser - Google Patents

Photodetector using semiconductor laser

Info

Publication number
JPS57169935A
JPS57169935A JP56055866A JP5586681A JPS57169935A JP S57169935 A JPS57169935 A JP S57169935A JP 56055866 A JP56055866 A JP 56055866A JP 5586681 A JP5586681 A JP 5586681A JP S57169935 A JPS57169935 A JP S57169935A
Authority
JP
Japan
Prior art keywords
photodetector
semiconductor laser
beam splitter
fresnel rhombus
fluctuation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP56055866A
Other languages
Japanese (ja)
Inventor
Michiharu Abe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP56055866A priority Critical patent/JPS57169935A/en
Publication of JPS57169935A publication Critical patent/JPS57169935A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/13—Optical detectors therefor

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Head (AREA)

Abstract

PURPOSE:To accurately operate a photodetector regardless of the fluctuation of oscillated wavelength due to temperature change, by making a semiconductor laser beam incident to a detecting plane through a polarised beam splitter and a Fresnel rhombus and introducing the reflected light to the photodetector through the reflection at the beam splitter. CONSTITUTION:A laser beam from a semiconductor laser 1 is condensed on an optical disc 6 with a condenser lens 5 through a coupling lens 2, a polarized beam splitter 3 and a Fresnel rhombus 9. The reflected light goes reversing, it passes through the Fresnel rhombus 9, and the polarized plane is rotated by 90 deg. and reflected on the splitter 3 and made incident to a photodetector 7. Since the Fresnel rhombus keeps the function over a considerably broad range, the detector operates accurately regardless of the fluctuation of the oscillated wavelength of the semiconductor laser 1 due to temperature change.
JP56055866A 1981-04-14 1981-04-14 Photodetector using semiconductor laser Pending JPS57169935A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56055866A JPS57169935A (en) 1981-04-14 1981-04-14 Photodetector using semiconductor laser

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56055866A JPS57169935A (en) 1981-04-14 1981-04-14 Photodetector using semiconductor laser

Publications (1)

Publication Number Publication Date
JPS57169935A true JPS57169935A (en) 1982-10-19

Family

ID=13010989

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56055866A Pending JPS57169935A (en) 1981-04-14 1981-04-14 Photodetector using semiconductor laser

Country Status (1)

Country Link
JP (1) JPS57169935A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6045950A (en) * 1983-08-24 1985-03-12 Asahi Optical Co Ltd Optical information reader
US7180666B2 (en) * 2002-06-28 2007-02-20 Thomson Licensing Polarized light illumination device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6045950A (en) * 1983-08-24 1985-03-12 Asahi Optical Co Ltd Optical information reader
US7180666B2 (en) * 2002-06-28 2007-02-20 Thomson Licensing Polarized light illumination device

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