Unlock instant, AI-driven research and patent intelligence for your innovation.

Optical attenuator and optical head device

A technology of optical head device and attenuator, which is applied in the direction of optical recording head, beam guiding device, optics, etc., and can solve problems such as increased noise and unstable output light quantity

Inactive Publication Date: 2008-05-14
ASAHI GLASS CO LTD
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, some semiconductor lasers used have the problem of increased noise or unstable output light when the input current is reduced in order to reduce the amount of emitted light.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Optical attenuator and optical head device
  • Optical attenuator and optical head device
  • Optical attenuator and optical head device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0036] figure 1 An example of the optical attenuator of the present invention is shown. It sets transparent electrodes 103 and 104 such as ITO on transparent substrates 101 and 102 such as glass and plastic. Orientation films 105 and 106 such as polyimide are formed again, and two transparent substrates are arranged after implementing orientation treatment such as rubbing, so that the gaps at even intervals are separated from each other, and they are bonded with an adhesive (not shown) or the like. The surrounding area forms a unit structure. Liquid crystal is sealed inside the cell to form a liquid crystal layer 107 . As the liquid crystal, for example, a nematic liquid crystal can be used, and a chiral material can also be added.

[0037] The transparent electrodes 103 and 104 are connected to a voltage control part 109 to which a voltage can be applied from the outside to form a liquid crystal part 130 . The liquid crystal molecules 108 can be aligned so that they form ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
angleaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

The present invention provides an optical attenuator reducing variations in optical attenuation amount in response to temperature change, and an optical head device having properties excellent in recording and reproducing an information. An optical attenuator comprising a liquid crystal element having spirally arranged molecules in which a liquid crystal layer 107 is sandwiched between transparent electrodes 103 and 104, and a polarizing beam splitter 110 whose transmittance is changed depending on a polarization state, wherein the ordinary refractive index (no) and the extraordinary refractive index (ne) of liquid crystal, the angle ([theta]pt) of liquid crystal molecules against the transparent substrate surfaces, the thickness (d) of the liquid crystal layer 107 and the wavelength ( lambda ) of incident light, constituent elements are configured so that the value A satisfies the range of from 0.5 to 1.5 in the conditional formula defined by the formula (1): A = DELTA n . d DIVIDED lambda wherein DELTA n = no . ne / n<2>o . cos<2>([theta]pt) + n<2>e . sin<2>([theta]pt) - no .

Description

technical field [0001] The present invention relates to an optical attenuator and an optical head device, in particular to an optical head device used for recording and reproducing information on an optical recording medium and an optical attenuator mounted on the optical head device. Background technique [0002] In recent years, optical recording media capable of recording and / or reproducing information by irradiating light have been widely used. As such an optical recording medium, for example, a read-only CD-ROM in which a fine concave-convex pattern is formed on a substrate based on recorded information is known. [0003] In addition, as this optical recording medium, for example, there are known magneto-optical disks that reproduce information using the magnetic Kerr effect, phase-change optical disks with a signal recording layer formed of a phase-change material, and CD-Rs. A recordable optical disc or the like in which recording marks are formed on a signal recordi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G02F1/13G11B7/135G11B7/1369G11B7/1381
Inventor 村田浩一大泽光生
Owner ASAHI GLASS CO LTD
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com