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WO2001095024A1 - Dispositifs commutables de guide d'ondes - Google Patents

Dispositifs commutables de guide d'ondes Download PDF

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Publication number
WO2001095024A1
WO2001095024A1 PCT/GB2001/002491 GB0102491W WO0195024A1 WO 2001095024 A1 WO2001095024 A1 WO 2001095024A1 GB 0102491 W GB0102491 W GB 0102491W WO 0195024 A1 WO0195024 A1 WO 0195024A1
Authority
WO
WIPO (PCT)
Prior art keywords
waveguide
switchable
fringes
electric field
holographic
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.)
Ceased
Application number
PCT/GB2001/002491
Other languages
English (en)
Inventor
Milan Momcilo Popovich
John James Storey
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.)
DigiLens Inc
Original Assignee
DigiLens Inc
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
Priority claimed from GB0014060A external-priority patent/GB0014060D0/en
Priority claimed from GB0017091A external-priority patent/GB0017091D0/en
Application filed by DigiLens Inc filed Critical DigiLens Inc
Priority to AU2001262522A priority Critical patent/AU2001262522A1/en
Publication of WO2001095024A1 publication Critical patent/WO2001095024A1/fr
Anticipated expiration legal-status Critical
Ceased 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
    • G02F1/1326—Liquid crystal optical waveguides or liquid crystal cells specially adapted for gating or modulating between optical waveguides
    • 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 
    • G02F1/011—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  in optical waveguides, not otherwise provided for in this subclass
    • G02F1/0115—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  in optical waveguides, not otherwise provided for in this subclass in optical fibres
    • 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
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1334—Constructional arrangements; Manufacturing methods based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
    • G02F1/13342—Holographic polymer dispersed liquid crystals
    • 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
    • G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/30—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 grating
    • G02F2201/307—Reflective grating, i.e. Bragg grating

Definitions

  • This invention relates to switchable waveguide devices, such as those used in telecommunications systems.
  • Switchable waveguides are typically used in the telecommunications industry for wavelength divisional multiplexing, attenuation, line testing and dynamic gain equalisation.
  • waveguides in general are subject to losses due to changes in polarisation arising from e.g. fluctuations in the laser sources and from thermal or mechanical disturbances in the fibre itself. It is necessary to make those losses as low as possible: for example, Bellcore have published industry standards which demand polarisation losses of less than 0.2 dB. Whereas it may be possible to compensate for rotation of the polarisation vector by using electro- optical devices, these are likely to be expensive cumbersome and generally impractical to implement within practical telecommunications devices.
  • a switchable waveguide device comp ⁇ sing: an electrically switchable holographic composite configured as an elongate waveguide and having holographic f inges recorded therein, said fringes being composed of liquid crystal droplets whose molecules exhibit a preferred orientation with respect to a polar axis of each droplet, said droplets in a rest state of said composite having their polar axes oriented randomly in three dimensions, and means operative to apply an electric field to said holographic composite thereby to re-orient said molecules such that the polar axes of the droplets lie uniformly in a direction parallel to said radiation propagation direction, or such that said polar axes are randomly oriented in a plane perpendicular to said radiation propagation direction, such re-orientation of the liquid crystal molecules causing said holographic fringes to be activated and deactivated.
  • the said means operative to apply an elect ir of electrodes.
  • the electrodes are spaced apart transversely of the waveguide, such that said electric field is orthogonal to the longitudinal direction of the waveguide.
  • the electrodes are spaced apart longitudinally of the waveguide, such that said electrical field extends generally longitudinally of the waveguide.
  • the electrodes are positioned longitudinally beyond the ends of the area occupied by the fringes.
  • the electrodes are of generally annular configuration and extend around the waveguide.
  • each electrode comprises portions which alternate with portions of the other electrode longitudinally of the waveguide.
  • each electrode can comprise a plurality of fingers extending transversely of the waveguide, with the fingers of one electrode alternating with the fingers of the other electrode longitudinally of the waveguide.
  • the electrodes can comprise a plurality of hoop portions which extend around the waveguide and which alternate with one another longitudinally of the waveguide.
  • the holographic fringes are absent from the waveguide in regions that are adjacent to said electrodes or electrode portions.
  • the holographic fringes are formed as a reflection hologram, and when activated are operative to reflect an incident beam of radiation back along the waveguide.
  • the liquid crystal droplets of said holographic composite are dispersed in a surrounding medium (such as a polymer), and in one arrangement the refractive index of said
  • the waveguide device comprises holographic fringes recorded in two or more separate regions of said composite which are spaced apart longitudinally of the waveguide, and a respective means operative to apply an electric field to each of said regions.
  • the said respective means are preferably independently operable. 15
  • Figures 1 and 2 are diagrams showing a holographic material in two different states
  • Figures 3 A and 3B are diagrams showing the optical characteristics of a liquid crystal droplet which forms part of the material shown in Figures 1 and 2;
  • Figure 4 is a diagram showing another form of holographic material
  • Figure 5 is a schematic sectional side view of a first embodiment of a switchable waveguide device according to the present invention
  • Figure 6 is a schematic perspective view of part of the device shown in Figure 5;
  • Figures 7 and 8 are diagrams showing a holographic material of the waveguide device respectively when in its rest and de-activated states;
  • Figure 9 is a schematic sectional side view of a modified version of the device shown in Figure 5;
  • Figure 10 is a sectional view showing the linldn; aveguide device according to the present invention with a conventional waveyuiue,
  • Figure 11 is a schematic sectional side view of a second embodiment of a switchable waveguide device according to the present invention.
  • Figure 12 is a perspective view of a third embodiment of a switchable waveguide device according to the present invention.
  • Figure 13 is an exploded view of the device shown in Figure 12;
  • Figure 14 is a detailed view of electrodes which from part of the device shown in Figures 12 and 13;
  • Figure 15 is a diagram showing the modulated refractive index distribution in a switchable waveguide device according to the present invention.
  • Figure 16 is a diagram of computed spectral response for the modulated distribution indicated in Figure 15.
  • the present invention is concerned with minimising polarisation losses by utilising a waveguide which comprises an optical medium in which holographic fringes (preferably of the Bragg type) are recorded, these fringes being switchable between active and inactive states by the application of an external electrical stimulus.
  • the optical medium typically ⁇ ⁇ .. comprises a polymer-dispersed liquid crystal (PDLC) material which, in its most fundamental 5 form, includes a monomer and a liquid crystal material: it can however, also include a cross- linking monomer, a co-initiator and a photo initiator dye.
  • the material can also be ultraviolet exposed.
  • the material undergoes phase separation during the hologram recordal process, creating fringes comprising regions densely populated bv liquid crystal micro-droplets interspersed with regions of clear polymer.
  • an ;d to the material0 by way of electrodes the natural orientation of the uqui ⁇ crystal molecules is changed, causing the refractive index modulation of the fringes to reduce and the hologram diffraction efficiency to drop to a very low level, thereby effectively erasing the hologram.
  • the optical characteristics of the material thus result from an ability to control the refractive index mismatch between the liquid crystal droplets and the surrounding polymer.
  • Using such a system,5. it is possible to achieve very fast switching rates, typically with a switching time of less than 150 microseconds, and perhaps as low as a few microseconds. '
  • the holographic medium has two optical states corresponding to the electrical stimulus being on or off, these being equivalent respectively to the hologram being disabled or activated.
  • the liquid crystal0 droplets tend to be randomly aligned.
  • the droplets tend to re-orient such that the liquid crystal molecules become aligned with the direction of the applied electric field.
  • Such a material is said to have positive anisotropy.
  • the liquid crystal molecules in their rest state are generally oriented at right-angles to the above, and become re-oriented perpendicularly to the applied5 electric field: such a material is said to have negative anisotropy.
  • Figure 1 shows a typical arrangement of the liquid crystal droplets (referenced 10) in their rest state. Within each droplet, there is a tendency for the liquid crystal molecule directors to exhibit a bipolar alignment pattern, as indicated schematically by lines 11, with the polar axis being indicated at P.
  • One of the droplets 10 is shown in detail in Figures 3A and 3B, with Figure 3A being a view perpendicular to the polar axis P and Figure 3B being a view parallel to that axis. Because of the way in which the molecule directors are orientated, the droplet will exhibit birefringence. More particularly, for radiation incident in a direction parallel to the polar axis P (i.e.
  • the droplet will have an ordinary refractive index n 0 , whereas for radiation incident perpendicularly to the polar axis (i.e. as viewed in Figure 3A) the droplet will have an extraordinary refractive index n e , with n e generally being greater than n 0 .
  • the 1 rest state would exhibit polarisation sensitivity for light incident in a uuct u ⁇ ⁇ a vicwcu in Figure 1.
  • this is not the case because the droplets 10 are randomly orientated ⁇ throughout the volume of the material.
  • the polar axes P of the droplets are also arranged randomly, s ⁇ the material does not show any net average preferred polarisation direction.
  • FIG. 2 shows (for one particular type of PDLC material) a typical arrangement of the liquid crystal droplets 10 in the state where an electric field is applied in the direction of arrow E (i.e. into the plane of the drawing).
  • the droplets 10 now become re-oriented such that their polar axes P are aligned with the electric field vector (assuming that the PDLC material has positive anisotropy).
  • n 0 the ordinary refractive index
  • PDLC material shows no dependence upon the polarisation state of the incident radiation, because in the rest state the polar axes of the liquid crystal droplets are randomly oriented with respect to a plane perpendicular to the radiation propagation direction, so that any polarisation sensitivity is averaged out.
  • the polar axes become uniformly aligned in a direction parallel to the radiation propagation direction, and therefore exhibit only their ordinary refractive index to the radiation.
  • the polar axes P of the liquid crystal droplets 10 are randomly oriented in three dimensions.
  • the material shows no net polarisation sensitivity in this condition because of the randomness of the orientation of the liquid crystal droplets.
  • the polar axes P become randomly oriented in a plane perpendicular to the radiation propagation direction.
  • the material shows no polarisation sensitivity in this condition, because the radiation sees only liquid crystal droplets whose polar axes are randomly oriented, so anv ⁇ olarisation effects are balanced out.
  • the PDLC material can be of either of the above general types, i.e. switchable between a first condition in which the liquid crystal droplets are randomly oriented in three dimensions and a second condition in which the droplets are either uniformly aligned or are randomly oriented in a plane perpendicular to the direction of radiation propagation.
  • a switchable waveguide device which comprises a length of capillary tube 20 comprising an inner capillary or core 21 typically of five microns diameter and an outer tubular cladding 22 typically of 80 microns external diameter.
  • the core 21 is formed of PDLC material and has recorded therein a series of holographic fringes (represented schematically by lines 23).
  • the fringes are recorded in two separate regions 24 and 25 of the core 21 which are spaced apart longitudinally of the latter, although more or fewer such regions can be provided, depending upon the desired application of the device.
  • One of these regions is shown in more detail in Figure 6, it being understood that the other region is substantially identical.
  • each of the regions 24 and 25 Provided in each of the regions 24 and 25 are a respective pair of annular electrodes 26 and 27 in the form of electrically conductive hoops which encircle the exterior of the capillary tube 20.
  • An electrical stimulus can be applied across the electrodes in each pair by means of a respective voltage source 28 (shown schematically in Figure 6) thereby producing an electric field between the electrodes.
  • the field is of toroidal configuration as indicated by arrows 29, but the electrodes 24 and 25 themselves are positioned beyond the ends of the area occupied by the respective fringes such that in that area the electric field effectively extends longitudinally of the core 21, as indicated by arrow 29'.
  • this shows the fringes 23 in the rest state of the PDLC material, i.e. when the electric field is switched off.
  • the fringes 23 are formed by liquid crystal droplets 30 in which the polar axes are orient ited by lines 31.
  • the fringes 23 act as a reflection ho.ugiam anu lencui ⁇ ack any incident radiation propagating along .the core 21, as indicated by arrow A.
  • the droplets 30 present themselves to the incident radiation in the manner described previously with reference to Figure 1 so the PDLC material does not show any polarisation sensitivity in this condition.
  • Figure 8 shows the PDLC material when the electric field (as represented by arrow E) is turned on. Since in this arrangement the material is of a type having positive anisotropy, the polar axes 31 of the liquid crystal droplets 30 become aligned parallel to the electric field E, and this effectively erases the hologram. Incident radiation is therefore able to continue its propagation along the core 21, as indicated by arrow B. In this condition, the liquid crystal droplets present themselves to the incident radiation in the manner described previously with reference to Figure 2, so again the PDLC material does not show any polarisation sensitivity.
  • fringes are shown as extending generally perpendicular to the core, they can instead be slightly slanted.
  • Figure 9 shows a modified arrangement in which the electrode pairs are interdigitated in the longitudinal direction of the capillary tube 20. More particularly, the electrode 26 comprises a plurality of hoop portions 26a, 26b etc whilst the electrode 27 similarly comprises a plurality of hoop portions 27a etc, with the former alternating with the latter in equally- spaced relationship along the capillary tube 20. This arrangement is useful in increasing the interaction length between the electrodes and the fringes.
  • Electrodes 26 and 27 are arranged to be offset from the core 21, e.g. as depicted schematically in Figure 9.
  • Figure 10 shows the connection of the above-describe D a conventional waveguide 40 which comprises an optical fibre core 4 ⁇ surroun ⁇ e ⁇ oy a snica sheath 42.
  • An end of the capillary tube 20 is abutted against the waveguide 40 within a ferrule 43, such that the core 21 and the core 41 are co-axially aligned.
  • the waveguide 40 and the ferrule 43 are preferably items manufactured by Vitrocom.
  • a suitable gel can be used between the abutting ends of the waveguide 40 and the capillary tube 20 to match the refractive indices of the cores 21 and 41.
  • FIG 11 shows a second embodiment of a switchable waveguide device, which is generally similar to that described above with reference to Figure 5: accordingly, similar parts have been accorded the same reference numerals.
  • the electrodes 26 and 27 in each pair are generally planar and are disposed on opposite sides of the capillary tube 20.
  • the external surface of the tube 20 can have flats machined thereon to accommodate these electrodes.
  • an electric field is generated which extends transversely of the core 21 of the capillary tube 20, as indicated by arrows 43.
  • the waveguide device of the invention is interposed between two conventional waveguides 40.
  • the device can be regarded as comprising two separate switching arrangements (denoted as X and Y). Each of these switching arrangements is disposed adjacent to arespective end of the overall switching device, and is composed of a region of the PDLC material in which the fringes are recorded, plus the associated electrodes 26 and 27.
  • the left-hand switching arrangement X is activated (i.e. when the electrodes are not energised)
  • the fringes 23 operate to reflect back any radiation propagating along the left-hand waveguide 40.
  • the arrangement when the fringes 23 of the switching arrangement Y are activated, the arrangement operates to reflect back any radiation propagating along the right-hand waveguide 40.
  • forward propagation of radiation can be enabled (either in the leftward or rightward direction) by energising the electrodes of both switching arrangements, thereby de-activating both sets of fringes.
  • the arrangements X and Y can form part of a common switching device and can be operated in unison. It is possible 5 formed by the fringes of one arrangement to have a different spatial frequent l y um mo nniges in the other arrangement, such that each of the arrangements X and Y acts upon a respectively different wavelength of radiation propagating along the waveguide.
  • Figures 12 and 13 show a third embodiment of a switchable waveguide device.
  • the device comprises an optical fibre 50 having an outer cladding 50a and a central core 50b within which are recorded holographic fringes in the form of a Bragg grating 51.
  • the fibre 50 is housed in a channel 52 formed in one surface 53 of a silica block 54, the channel 52 being of generally convex configuration so as to impart a convexity to the fibre.
  • the region of the fibre 50 which contains the grating 51 stands slightly proud of the surface 53.
  • the fibre is machined flat in this area so that it becomes flush with the surface 53, thereby exposing the part of the core 50b which contains the grating 51 (as can be seen to advantage in Figure 13).
  • the grating 51 can have a uniform fringe spacing or can be chirped.
  • the exposed grating is covered by a cladding 55 which is applied to the surface 53 of the silica block 54.
  • the cladding 55 is composed of a layer 56 of PDLC material on which are deposited a series of electrode pairs 57 and 58.
  • Each electrode in each pair comprises a plurality of fingers 59 which extends transversely of the fibre 50, the fingers of one electrode being interdigitated with fingers of the other. This arrangement is shown in more detail in Figure 14.
  • the refractive index of the layer 56 is chosen to match that of the cladding 50a of the fibre 50. In a typical arrangement, fingers 59 are 5 microns wide and the spacing between adjacent fingers is approximately 20 microns.
  • the length of the grating 51 and the span of each electrode pair 57, 58 will depend upon the required interaction length, which will in turn be determined by the desired application of the device.
  • the grating is made of discontinuous form, so that there are no fringes in the areas immediately adj acent to the electrodes. Careful design is required to ensure that spectral peaks resulting from the contribution of the electrode spatial frequency are minimised.
  • Figure 15 shows in diagrammatic form a typical example of the modulated refractive index of the Bragg grating that can be used in such circumstances.
  • the electrodes are 5 microns in width
  • the electrode separation is 20 microns
  • the modulation of the refractive index is 0.0007
  • the average refractive index is 1.52
  • the Bragg fringe separation is approximately 0.5 microns.
  • Figure 16 shows a computed spectral response for such a grating.
  • the resultant curve shows a peak 60 corresponding to the wavelength for which the grating is designed.
  • There are also side lobes 61 corresponding to the modulation of the grating, but these are much smaller than the response at the Bragg wavelength.
  • the Bragg gratings formed by the holographic fringes can be simple constant frequency gratings, or can be chirped (i.e. such that the grating frequency varies along its length). In the latter case, the waveguide device can be used to act upon radiation of differing wavelengths (to which the Bragg grating is tuned).
  • the electrodes are spaced apart longitudinally of the waveguide, so that the electric field extends generally in the longitudinal direction of the waveguide.
  • the electrodes can be spaced apart transversely of the waveguide, so that the electric field is orthogonal to the longitudinal direction of the waveguide. This will, however, require consequential re-design of the fringes so that they can still be activated and de-activated by the application of the electric field.
  • the electrodes can take other forms apart from those described above.

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

Abstract

Des franges holographiques (23) sont insérées dans un matériau de cristal liquide dispersé dans un polymère, lequel matériau est configuré comme un guide d'ondes (21) (tel que le centre d'une fibre optique). Ces franges holographiques sont composées de gouttelettes de cristal liquide (30) dont les molécules présentent une orientation préférée par rapport à un axe polaire (31) de chaque gouttelette. Dans un état de repos du matériau, les axes polaires (31) sont orientés au hasard en trois dimensions. Bien que chaque gouttelette individuelle (30) présente une biréfringence et qu'elle soit par conséquent sensible à l'état de polarisation du rayonnement incident (A), à cause de cette orientation au hasard, cette sensibilité s'égalise dans le volume du matériau. Les franges (23) peuvent être effacées par l'application d'un champ électrique (E) qui provoque la réorientation des molécules de cristal liquide dans une direction uniforme, plus spécifiquement parallèlement à la direction de propagation du rayonnement. Ainsi, le cristal liquide dispersé dans un polymère ne présente aucune sensibilité à l'état de polarisation du rayonnement dans aucune de ces conditions. Dans un mode de réalisation différent, l'application du champ électrique (E) provoque la réorientation des axes polaires (31) de manière qu'ils soient orientés au hasard dans une perpendiculaire du plan à la direction de propagation du rayonnement. A nouveau, cette orientation au hasard permet de faire la moyenne de la sensibilité à la polarisation des gouttelettes individuelles (30).
PCT/GB2001/002491 2000-06-09 2001-06-07 Dispositifs commutables de guide d'ondes Ceased WO2001095024A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001262522A AU2001262522A1 (en) 2000-06-09 2001-06-07 Switchable waveguide devices

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB0014060A GB0014060D0 (en) 2000-06-09 2000-06-09 Waveguide device based on electrically switchable bragg grating
GB0014060.8 2000-06-09
GB0017091A GB0017091D0 (en) 2000-07-13 2000-07-13 Switchable waveguide devices
GB0017091.0 2000-07-13

Publications (1)

Publication Number Publication Date
WO2001095024A1 true WO2001095024A1 (fr) 2001-12-13

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1482352A1 (fr) * 2003-05-29 2004-12-01 Agilent Technologies Inc Guide d'ondes optiques comprenant un coeur ayant un indice de réfraction indépendant de la polarisation et spatialement reconfigurable

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999009440A1 (fr) * 1997-08-13 1999-02-25 Foster-Miller, Inc. Composants optiques commutables
US5937115A (en) * 1997-02-12 1999-08-10 Foster-Miller, Inc. Switchable optical components/structures and methods for the fabrication thereof
EP0977077A2 (fr) * 1998-07-28 2000-02-02 Nippon Telegraph and Telephone Corporation Dispositif optique et appareil d'affichage

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5937115A (en) * 1997-02-12 1999-08-10 Foster-Miller, Inc. Switchable optical components/structures and methods for the fabrication thereof
WO1999009440A1 (fr) * 1997-08-13 1999-02-25 Foster-Miller, Inc. Composants optiques commutables
EP0977077A2 (fr) * 1998-07-28 2000-02-02 Nippon Telegraph and Telephone Corporation Dispositif optique et appareil d'affichage

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
SUTHERLAND R L ET AL: "SWITCHABLE HOLOGRAMS IN NEW PHOTOPOLYMER-LIQUID CRYSTAL COMPOSITE MATERIALS", PROCEEDINGS OF THE SPIE, SPIE, BELLINGHAM, VA, US, February 1995 (1995-02-01), pages 132 - 143, XP000853766 *
TAKIZAWA K ET AL: "POLARIZATION-INDEPENDENT OPTICAL FIBER MODULATOR BY USE OF POLYMER-DISPERSED LIQUID CRYSTALS", APPLIED OPTICS, OPTICAL SOCIETY OF AMERICA,WASHINGTON, US, vol. 37, no. 15, 20 May 1998 (1998-05-20), pages 3181 - 3189, XP000765274, ISSN: 0003-6935 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1482352A1 (fr) * 2003-05-29 2004-12-01 Agilent Technologies Inc Guide d'ondes optiques comprenant un coeur ayant un indice de réfraction indépendant de la polarisation et spatialement reconfigurable
US7974510B2 (en) 2003-05-29 2011-07-05 Agilent Technologies, Inc. Optical waveguide having a core with a polarization-independent, spatially reconfigurable refractive index

Also Published As

Publication number Publication date
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