JPH01169746A - Pickup device for optical disk - Google Patents

Pickup device for optical disk

Info

Publication number
JPH01169746A
JPH01169746A JP62326017A JP32601787A JPH01169746A JP H01169746 A JPH01169746 A JP H01169746A JP 62326017 A JP62326017 A JP 62326017A JP 32601787 A JP32601787 A JP 32601787A JP H01169746 A JPH01169746 A JP H01169746A
Authority
JP
Japan
Prior art keywords
laser
vertical mode
fiber
noises
mode interval
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
JP62326017A
Other languages
Japanese (ja)
Inventor
Masataka Mori
Original Assignee
Mitsubishi Electric Corp
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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP62326017A priority Critical patent/JPH01169746A/en
Publication of JPH01169746A publication Critical patent/JPH01169746A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To shorten the vertical mode interval of returning beams and to reduce noises of a laser beam by making the length of a single mode fiber 100mm or above.
CONSTITUTION: A laser beam emitted from a semiconductor 1 is made incident on the single mode fiber 3 of 100mm long or above by a condensor lens 2. The laser beam passing through the fiber 3 is made to parallel rays of light by a collimator lens 4, then the rays of light pass through a polarizing beam splitter 5 and a λ/4 plate 6, then condensed by a condensor lens 7 to form a spot on an optical disk 8. A reflected beam is bent by the beam splitter 5 toward a condensor lens 9 and condensed on a photodiode 10. The vertical mode interval of the laser diode is reversely proportionate to the length of an external resonator, hence the longer the vertical mode interval is the larger the noises are. Since the single mode fiber 3 is made to 100mm or above, the resonator becomes longer, and the vertical mode interval becomes shorter, as a result, noises become smaller.
COPYRIGHT: (C)1989,JPO&Japio
JP62326017A 1987-12-23 1987-12-23 Pickup device for optical disk Pending JPH01169746A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62326017A JPH01169746A (en) 1987-12-23 1987-12-23 Pickup device for optical disk

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62326017A JPH01169746A (en) 1987-12-23 1987-12-23 Pickup device for optical disk

Publications (1)

Publication Number Publication Date
JPH01169746A true JPH01169746A (en) 1989-07-05

Family

ID=18183162

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62326017A Pending JPH01169746A (en) 1987-12-23 1987-12-23 Pickup device for optical disk

Country Status (1)

Country Link
JP (1) JPH01169746A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999050843A1 (en) * 1998-03-30 1999-10-07 Seagate Technology, Llc. Optical data storage system with means for reducing noise from spurious reflections
WO1999050844A1 (en) * 1998-03-30 1999-10-07 Seagate Technology Llc Optical data storage system utilizing polarization maintaining optical fiber
US6298027B1 (en) 1998-03-30 2001-10-02 Seagate Technology Llc Low-birefringence optical fiber for use in an optical data storage system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6467726A (en) * 1987-09-09 1989-03-14 Seiko Epson Corp Optical pick-up

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6467726A (en) * 1987-09-09 1989-03-14 Seiko Epson Corp Optical pick-up

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999050843A1 (en) * 1998-03-30 1999-10-07 Seagate Technology, Llc. Optical data storage system with means for reducing noise from spurious reflections
WO1999050844A1 (en) * 1998-03-30 1999-10-07 Seagate Technology Llc Optical data storage system utilizing polarization maintaining optical fiber
US6298027B1 (en) 1998-03-30 2001-10-02 Seagate Technology Llc Low-birefringence optical fiber for use in an optical data storage system

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