FR2319916A1 - Smectic:A phase liq. crystal recording and memory system - modifies molecular arrangement and optical properties by electric writing field - Google Patents

Smectic:A phase liq. crystal recording and memory system - modifies molecular arrangement and optical properties by electric writing field

Info

Publication number
FR2319916A1
FR2319916A1 FR7523627A FR7523627A FR2319916A1 FR 2319916 A1 FR2319916 A1 FR 2319916A1 FR 7523627 A FR7523627 A FR 7523627A FR 7523627 A FR7523627 A FR 7523627A FR 2319916 A1 FR2319916 A1 FR 2319916A1
Authority
FR
France
Prior art keywords
liq
crystal
optical properties
smectic
molecular arrangement
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.)
Granted
Application number
FR7523627A
Other languages
French (fr)
Other versions
FR2319916B1 (en
Inventor
Michel Goscianski
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.)
Laboratoires dElectronique Philips SAS
Original Assignee
Laboratoires dElectronique et de Physique Appliquee
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 Laboratoires dElectronique et de Physique Appliquee filed Critical Laboratoires dElectronique et de Physique Appliquee
Priority to FR7523627A priority Critical patent/FR2319916A1/en
Publication of FR2319916A1 publication Critical patent/FR2319916A1/en
Application granted granted Critical
Publication of FR2319916B1 publication Critical patent/FR2319916B1/fr
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/132—Thermal activation of liquid crystals exhibiting a thermo-optic effect
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
    • G02F1/13781—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering using smectic liquid crystals
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
    • G11C13/04—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using optical elements ; using other beam accessed elements, e.g. electron or ion beam
    • G11C13/047—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using optical elements ; using other beam accessed elements, e.g. electron or ion beam using electro-optical elements

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal (AREA)

Abstract

Data are represented by modifications of the optical properties of a liq. crystal system. An electrical writing field is used to modify the molecular arrangement in the liq crystal and thus its optical properties. The orientation of the molecules in the initial smectic-A state depends upon the sign of the dielectric anisotropy. The liq. crystal system is illuminated by a readout beam. The electric field then induces faults in the liq. crystal s.t. the beam becomes diffused. The final orientation of the molecules is homeotropic when the electric field exceeds a threshold level. The liq. crystal system may be placed between two crossed polarizers orientated at 45 deg. to the alingment direction of the molecules in the liq. crystal.
FR7523627A 1975-07-29 1975-07-29 Smectic:A phase liq. crystal recording and memory system - modifies molecular arrangement and optical properties by electric writing field Granted FR2319916A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7523627A FR2319916A1 (en) 1975-07-29 1975-07-29 Smectic:A phase liq. crystal recording and memory system - modifies molecular arrangement and optical properties by electric writing field

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7523627A FR2319916A1 (en) 1975-07-29 1975-07-29 Smectic:A phase liq. crystal recording and memory system - modifies molecular arrangement and optical properties by electric writing field

Publications (2)

Publication Number Publication Date
FR2319916A1 true FR2319916A1 (en) 1977-02-25
FR2319916B1 FR2319916B1 (en) 1978-12-29

Family

ID=9158478

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7523627A Granted FR2319916A1 (en) 1975-07-29 1975-07-29 Smectic:A phase liq. crystal recording and memory system - modifies molecular arrangement and optical properties by electric writing field

Country Status (1)

Country Link
FR (1) FR2319916A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993020554A1 (en) * 1992-04-07 1993-10-14 Nematel Selectively modifiable optical data storage

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
*REVUE US "APPLIED PHYSICS LETTERS" VOL. 19, NO. 7, 1ER OCTOBRE 1971, PAGES 241-242, ARTICLE DE C.TANI "NOVEL ELECTRO-OPTICAL STORAGE EFFECT IN A CERTAIN SMECTIC LIQUID CRYSTAL") *
REVUE JA "JAPANESE JOURNAL OF APPLIED PHYSICS" VOL. 14, NO. 2, FEVRIER 1975, PAGES 216-219, ARTICLE DE K.YOSHINO ET AL. "CARRIER TRANSPORT AND ELECTRO-OPTIC EFFECTS IN SMECTIC LIQUID CRYSTAL" *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993020554A1 (en) * 1992-04-07 1993-10-14 Nematel Selectively modifiable optical data storage
US5532952A (en) * 1992-04-07 1996-07-02 Nematel Dr, R. Eidenshink Selectively alterable optical data memory

Also Published As

Publication number Publication date
FR2319916B1 (en) 1978-12-29

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Legal Events

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