+

WO1989006369A1 - Modulateur electro-optique - Google Patents

Modulateur electro-optique Download PDF

Info

Publication number
WO1989006369A1
WO1989006369A1 PCT/AU1988/000489 AU8800489W WO8906369A1 WO 1989006369 A1 WO1989006369 A1 WO 1989006369A1 AU 8800489 W AU8800489 W AU 8800489W WO 8906369 A1 WO8906369 A1 WO 8906369A1
Authority
WO
WIPO (PCT)
Prior art keywords
layers
reflector
electrooptic modulator
refractive index
modulator
Prior art date
Application number
PCT/AU1988/000489
Other languages
English (en)
Inventor
Peter Charles Kemeny
Original Assignee
Australian Telecommunications Corporation
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 Australian Telecommunications Corporation filed Critical Australian Telecommunications Corporation
Priority to JP89500688A priority Critical patent/JPH05501923A/ja
Priority to KR1019890701663A priority patent/KR900700859A/ko
Publication of WO1989006369A1 publication Critical patent/WO1989006369A1/fr

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 
    • G02F1/15—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 an electrochromic 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 
    • G02F1/21—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  by interference
    • G02F1/218—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  by interference using semi-conducting materials
    • 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 
    • G02F1/015—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 semiconductor elements having potential barriers, e.g. having a PN or PIN junction
    • G02F1/0151—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 semiconductor elements having potential barriers, e.g. having a PN or PIN junction modulating the refractive index
    • G02F1/0154—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 semiconductor elements having potential barriers, e.g. having a PN or PIN junction modulating the refractive index using electro-optic effects, e.g. linear electro optic [LEO], Pockels, quadratic electro optical [QEO] or Kerr effect

Definitions

  • This invention relates to an electro optic modulator.
  • the modulator of the invention is constructed from semi-conductor layers which are transparent to light over a wide range of wavelengths.
  • the device is able to modulate the intensity of transmitted or reflected light as well as the phase of transmitted or reflected light having a wavelength at or near a number of discrete wavelengths which bear a simple relationship to each other, as descripted later. These discrete operating wavelengths may be chosen arbitrarily within a wide range by adjusting the dimensions and/or composition of the device.
  • the modulation is effected by varying the voltage applied to the device to render it operative.
  • the invention provides an electrooptic modulator comprising structure defining a single crystal substrate, having some refractive index, on which are positioned, in succession, an inner reflector formed by a first set of epitaxial single crystal layers, a resonator layer, an outside reflector formed by a second set of epitaxial single crystal layers, at least one part of said structure, being of one or more of the inside reflector, substrate and resonator layer, being electrically conductive and of either p-type or n-type conduction, at least another part of said structure, being one or more of the outside reflector, and resonator layer, being made electrically conductive and being of either n-type or p-type conduction, but of different conduction type to said one part, said structure further including first and second electrically conductive means making ohmic contact respectively to said one part and said another part of said structure whereby to enable, by application of electrical potential to said electrically conductive means, a reverse bias to be applied to said structure to cause an electric field to be applied
  • the layers comprising the reflectors may have alternating high and low refractive indices and thicknesses such that a compositional periodicity of optical thickness ⁇ /2 or an odd multiple thereof is achieved where ⁇ is the longest of a number of possible discrete wavelengths of light to be modulated by the particular device. These discrete operating wavelengths may be chosen arbitrarily within a wide range by adjusting the dimensions and/or composition of the device.
  • the composition and hence the refractive index of the reflector can be varied in a continuous or piece-wise manner such that a compositional periodicity having optical thickness of ⁇ /2 or some odd multiple thereof is achieved.
  • the refractive index N r (V) varies as some function of the electric field present in the resonator layer, arising as the result of the external application of a potential difference. V, across the resonator, at least for some particular palorisations of light travelling through this layer in some particular direction.
  • the device has a maximum of transmission at wavelengths ⁇ given by:
  • r 1 is the amplitude of reflectance of layers comprised in the inner reflector
  • ⁇ 1 is the phase shift on such reflectance
  • r 2 is the amplitude of reflectance of layers in the outer reflector
  • ⁇ 2 is the phase shift on such reflectance
  • the refractive index N. of the layer of the inside reflector adjacent to the resonator layer, and N a , the refractive index of the layer of the outside reflector immediately adjacent the resonator layer should be related to N r (V), the refractive index of the resonator layer at any particular operating voltage across the modulator either by:
  • the modulator 10 shown in the drawing comprises a substrate 12 in the form of a single crystal having a refractive index N s .
  • the substrate may be provided on its "rear" face with one or more layers of material intended to reduce the reflectivity of the rear surface from its uncoated value, at the wavelength of operation of the modulator, and may have regions of metalisation intended to make ohmic contact to the device.
  • a layer 14 of metalisation is shown.
  • a first set of epitaxial single crystal layers 16 which together constitute an inside reflector 18.
  • the composition, thickness, and a number of these layers constitute variables which are selected to give desirable properties of reflectivity, electrical conduction, transparency, stablity and crystal growth parameters, in accordance with known factors for thin film optics and semiconductor technology.
  • the inside reflector is characterized in part, by its complex reflectance amplitude r.
  • r 1 is the magnitude of reflectance
  • a resonator layer Positioned immediately above and in contact with inside reflector 18 is a resonator layer with thickness "d” and refractive index N r (V) for light travelling through this layer, where V is the potential difference applied across the modulator.
  • This refractive index should have the property that either:
  • N b is the refractive index of the layer of the inside reflector 18 which is adjacent to the resonator layer and N a is the refractive index of that one of a number of layers 22 next described which is immediately adjacent and in contact with resonator layer 20, but at the opposite side thereof to inside reflector 18.
  • the resonator layer there is provided the aforementioned set of layers 22 each in the form of an epitaxial single crystal. These layers together constitute an outside reflector 24. As with the inside reflector 18, the layers 22 constituting the outside reflector are selected to give desirable properties of reflectivity, electrical conduction. transparency, stablity and crystal growth parameters, in accordance with known factors for thin film optics and semiconductor technology.
  • the outside reflector 24 may be characterized in part by its complex reflectance amplitude r where:
  • r 2 is the reflectance amplitude.
  • the reflector 24 is in contact with incident medium having refractive index N i .
  • the substrate and subsequent material layers may be single crystals composed of any compounds or alloys of the elements of the periodic table, or pure elements, suitable for the purpose.
  • the substrate and subsequent layers may be composed of Gallium, Aluminium and Arsenic combined in particular proportions in particular layers.
  • the substrate and subsequent . layers may be composed of Gallium, Indium, Arsenic, and Phosphorous combined in particular proportions in particular layers.
  • the substrate and subsequent layers may be composed of Gallium, Indium, Aluminium, Arsenic and Antimony combined in particular proportions in particular layers.
  • the substrate and subsequent layers may be composed of Mercury, Cadmium, Manganese and Tellurium combined in particular proportions in particular layers.
  • the substrate and subsequent layers may be composed of Lead , Sulphur Tellurium and Selenium combined in particular proportions in particular layers .
  • each of the said layers may in turn be composed of still finer layers , known as superlattice or as multi-quantum-well structures , or the said layers may be continuously graded in composition .
  • conduction of the first type may be by electrons (n-type) or holes (p-type) .
  • a f irst metalisation ( 14 ) appropriate to make ohmic contact to the doped material of the first conduction type is applied on the substrate 12 or elsewhere on or near the modulator so as to make ohmic contact to this doped material only.
  • Some part of the outs ide ref lector 24 and/or the resonator layer 20 is made electrically conducting by the incorporation of impurity atoms .
  • This conduction hereinafter cal led conduction of the second type, may be by electrons (n-type) or holes (p-type) . If the fi rst conduction type is n-type, then the second conduction type is p-type and if the f irst conduction type is p-type , the second conduction type is n-type .
  • a second meta lisation appropriate to make ohmic contact to the doped material of the second conduction type is applied on or near the modulator so as to make ohmic contact to this doped material only.
  • Such metalisation is shown as a metalised loop 30 formed on the surface 24a of outside reflector 24 remote from resonator layer 20.
  • One or more modulators 10 or groups of modulators 10 may be formed on the material structure by etching or by other means of isolation so that when a reverse bias voltage is applied between the metalisation making contact to those parts of the material structure which are respectively of first and second conduction types, and associated with a particular modulator or group of modulators an electric field is applied predominatly along a direct path between the n-type and p-type materials of each particular modulator so connected.
  • the reverse bias is, as is conventional, obtained by raising the electrical potential of the n-type material above that of the p-type material.
  • the modulator structure described here and illustrated in the figure may be partially or fully surrounded by materials including semiconductors (either irradiated by energetic particles such as protons or otherwise), polymers, or dielectrics to provide passivation, reduce or enhance surface recombination, provide optical confinement, or to enhance environmental stability.
  • the modulator may be any shape including square, rectangular, circular or ellipsoidal.
  • the side walls, if any, may be perpendicular to the susbtrate, or sloping or curved.
  • modulation of the transmission through the device of a beam of incident light of any particular wavelength ⁇ i is acheived by varying the applied voltage, V, hence the refractive index N r (V).
  • This variation in refractive index causes the wavelength positions of the transmission maxima of the modulator ⁇ m . to vary, according to the expression just above given, relative to the wavelength ⁇ i and hence the transmission of light by the modulator is modulated.
  • the intensity of the reflected light as well as the phases of the transmitted and reflected beams are also modulated.
  • the phase modulations arise as a result of the changing optical thickness of the resonator layer. To achieve optimum performance the modulator structure must be admittance matched to the incident medium.
  • m' may be selected to be 14, for example.
  • the modulator described here is suitable for operation at any wavelength within the transparency range of the materials of construction.
  • the resonator layer is chosen to be a multiquantum well structure, and the wavelength of operation is chosen to correspond to the excitonic region, just below the fundamental energy gap of the resonator layer, as revealed by Chemla et al in US patent 4,525,687 then the performance of the device will be significantly improved, compared to operation at other wavelengths.
  • the difference between the present device and that described by Chemla et al is:
  • the inside and outside reflectors of the present device provide the electrical contact to the multiquantum well resonator layer whereas in Chemla's device separate contacts are required.
  • Modulators formed in accordance with the invention have the significant advantage that they can be formed without requiring formation of mirror facets by cleaving, etching.
  • the modulator may for example, be a cylinder having a diameter of approximately 10 micrometres. This will yield good mode matching to small core optical fibres and thus, low insertion loss.
  • the power density at the input/outpur facets will be small compared to semiconductor waveguide modulators, thus allowing higher power operation without facet damage.
  • Modulators arranged in side by side position such as in linear or two-dimensional arrays may be readily constructed.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Developing Agents For Electrophotography (AREA)

Abstract

Modulateur électro-optique comportant un substrat monocristallin (12) sur lequel sont positionnés successivement un réflecteur intérieur (18), une couche résonatrice (20) et un réflecteur extérieur. Avec cet agencement on peut, par l'application d'un potentiel électrique, appliquer une polarisation inverse audit modulateur, afin de moduler la lumière passant par le modulateur en variant le potentiel électrique.
PCT/AU1988/000489 1988-01-06 1988-12-20 Modulateur electro-optique WO1989006369A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP89500688A JPH05501923A (ja) 1988-01-06 1988-12-20 光電変調器
KR1019890701663A KR900700859A (ko) 1988-01-06 1988-12-20 전기 광학 변조기

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPI619088 1988-01-06
AUPI6190 1988-01-06

Publications (1)

Publication Number Publication Date
WO1989006369A1 true WO1989006369A1 (fr) 1989-07-13

Family

ID=3772705

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1988/000489 WO1989006369A1 (fr) 1988-01-06 1988-12-20 Modulateur electro-optique

Country Status (6)

Country Link
EP (1) EP0397690A4 (fr)
JP (1) JPH05501923A (fr)
KR (1) KR900700859A (fr)
CN (1) CN1023839C (fr)
AU (1) AU2900789A (fr)
WO (1) WO1989006369A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5733775A (en) * 1995-02-27 1998-03-31 Slt Labinstruments Gesellschaft M.B.H. Temperature control device
CN101185020B (zh) * 2005-06-20 2011-12-28 日本电信电话株式会社 电光器件

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU653261B2 (en) * 1988-01-06 1994-09-22 Telstra Corporation Limited Current injection modulator

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3210980A1 (de) * 1981-04-01 1982-11-04 Nippon Telegraph & Telephone Public Corp., Tokyo Optisches schaltelement und optische schaltmatrix
WO1984003397A1 (fr) * 1983-02-28 1984-08-30 American Telephone & Telegraph Dispositif semiconducteur regulateur de lumiere utilisant des puits de quanta multiples

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3686395T2 (de) * 1985-11-27 1993-01-14 American Telephone & Telegraph Logisches optisches bauelement.
GB8610129D0 (en) * 1986-04-25 1986-05-29 Secr Defence Electro-optical device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3210980A1 (de) * 1981-04-01 1982-11-04 Nippon Telegraph & Telephone Public Corp., Tokyo Optisches schaltelement und optische schaltmatrix
WO1984003397A1 (fr) * 1983-02-28 1984-08-30 American Telephone & Telegraph Dispositif semiconducteur regulateur de lumiere utilisant des puits de quanta multiples

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0397690A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5733775A (en) * 1995-02-27 1998-03-31 Slt Labinstruments Gesellschaft M.B.H. Temperature control device
CN101185020B (zh) * 2005-06-20 2011-12-28 日本电信电话株式会社 电光器件

Also Published As

Publication number Publication date
KR900700859A (ko) 1990-08-17
AU2900789A (en) 1989-08-01
CN1023839C (zh) 1994-02-16
CN1034072A (zh) 1989-07-19
EP0397690A4 (en) 1991-09-11
JPH05501923A (ja) 1993-04-08
EP0397690A1 (fr) 1990-11-22

Similar Documents

Publication Publication Date Title
US5101293A (en) Electrooptic device for modulation of intensity and phase of transmitted or reflected light at discrete operating wavelengths
EP0898799B1 (fr) Obtention selective d'une longueur d'onde active au moyen de dispositifs resonants
US4923264A (en) Resonance coupled optical coupler with semiconductor waveguide layer comprising a multi-quantum-well structure
US5202897A (en) Fabry-perot modulator
US5345328A (en) Tandem resonator reflectance modulator
Carter et al. Nonlinear optical coupling between radiation and confined modes
JPH02129616A (ja) 光変調装置と方法
US5315430A (en) Strained layer Fabry-Perot device
GB2148595A (en) Distributed feedback semiconductor laser
WO1989008937A1 (fr) Commutation de polarisation dans les dispositifs actifs
US4817106A (en) Coupled waveguide injection laser
WO1989006369A1 (fr) Modulateur electro-optique
Wakita et al. Highly efficient InGaAs/InAIAs MQW waveguide phase shifter
AU652479B2 (en) Electrooptic modulator
US5093746A (en) Current injection modulator
AU653261B2 (en) Current injection modulator
US5157543A (en) Optical beam deflector
JPS6310125A (ja) 平面型光制御素子
EP1272896A2 (fr) Procede et appareil de pointage d'un faisceau optique
JP2686219B2 (ja) 光子バンド構造のミラー
CA2017971C (fr) Dispositifs de traitement optique a semiconducteur a structure mesa a centres de recombinaison ajoutes aux faces laterales pour accroitre la vitesse de fonctionnement
Zubrzycki et al. Design of an Integrated Optic Fabry-Perot Optical Modulator for Microwave Applications.
JPH03235915A (ja) 光機能素子
Dragoman et al. Modulators
JPH0488687A (ja) 波長可変半導体レーザ

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU JP KR US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1989900790

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1989900790

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1989900790

Country of ref document: EP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载