WO2009081487A1 - Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque - Google Patents

Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque Download PDF

Info

Publication number
WO2009081487A1
WO2009081487A1 PCT/JP2007/074864 JP2007074864W WO2009081487A1 WO 2009081487 A1 WO2009081487 A1 WO 2009081487A1 JP 2007074864 W JP2007074864 W JP 2007074864W WO 2009081487 A1 WO2009081487 A1 WO 2009081487A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
waveguide
optical
magneto
buffer layer
Prior art date
Application number
PCT/JP2007/074864
Other languages
English (en)
Japanese (ja)
Inventor
Hideki Yokoi
Original Assignee
Shibaura Institute Of Technology
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 Shibaura Institute Of Technology filed Critical Shibaura Institute Of Technology
Priority to PCT/JP2007/074864 priority Critical patent/WO2009081487A1/fr
Publication of WO2009081487A1 publication Critical patent/WO2009081487A1/fr

Links

Images

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 
    • G02F1/09—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 magneto-optical elements, e.g. exhibiting Faraday effect
    • G02F1/095—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 magneto-optical elements, e.g. exhibiting Faraday effect in an optical waveguide structure
    • G02F1/0955—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 magneto-optical elements, e.g. exhibiting Faraday effect in an optical waveguide structure used as non-reciprocal devices, e.g. optical isolators, circulators
    • 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
    • G02F2202/00—Materials and properties
    • G02F2202/28—Adhesive materials or arrangements

Definitions

  • the present invention relates to an optical nonreciprocal element.
  • Non-Patent Document 1 discloses a method of manufacturing an optical nonreciprocal element by bonding a magnetic garnet to a Si waveguide layer on which a rib waveguide is formed by direct bonding (wafer bonding). .
  • a hetero bond is usually formed by applying a heat treatment (for example, 800 ° C. to 900 ° C.) to the bonded substrate surface.
  • a heat treatment for example, 800 ° C. to 900 ° C.
  • the temperature during heat treatment for example, 220 ° C.
  • the present invention avoids the generation of cracks and magnetically avoids the occurrence of cracks when an optical nonreciprocal element is manufactured by laminating a Si waveguide layer having a waveguide and a magneto-optical material layer. It is an object of the present invention to provide a new technique capable of ensuring sufficient adhesion with an optical material layer.
  • the optical nonreciprocal element of the present invention is a Si waveguide layer obtained by forming a waveguide on the surface Si layer of an SOI substrate, and is disposed on the Si waveguide layer.
  • An adhesive buffer layer having a refractive index lower than the refractive index of the layer, and a magneto-optical material layer disposed on the adhesive buffer layer and causing a non-reciprocal phase change in light propagating through the waveguide. It is characterized by providing.
  • the magneto-optical material layer is magnetized in a direction perpendicular to the light propagation direction of the waveguide.
  • the adhesive buffer layer has a thickness of 20 nm or less.
  • the adhesive buffer layer is formed using any one of SOG, a photosensitive resist material, and an ultraviolet curable resin.
  • the magneto-optical material layer is formed of magnetic garnet.
  • An optical nonreciprocal device manufacturing method of the present invention includes a step of forming a Si waveguide layer having a waveguide on a surface Si layer of an SOI substrate, and 2.8 or more on the Si waveguide layer.
  • the Si waveguide layer is avoided while avoiding the generation of cracks. And sufficient adhesion between the magneto-optical material layer and the magneto-optical material layer.
  • FIG. 1 is a diagram showing an embodiment of the present invention, and shows a structure of an optical isolator using an optical nonreciprocal phase shift effect.
  • FIG. 2 is a view showing a structure when cut along AA ′ of FIG.
  • the optical isolator 100 includes an Si waveguide layer 1 formed on an SOI substrate having a Si / SiO 2 / Si layer structure, and an adhesive disposed on the Si waveguide layer 1.
  • the buffer layer 2 and the magneto-optical material layer 3 disposed on the adhesive buffer layer 2 are provided.
  • the SiO 2 layer of the SOI substrate has a thickness of about 2 ⁇ m or more and a refractive index of about 1.45, and functions as a lower cladding layer.
  • the Si waveguide layer 1 is a waveguide layer formed on the surface Si layer (thickness of about 200 nm) of the SOI substrate.
  • the Si waveguide layer 1 is provided with a rib waveguide 4, and its refractive index is about 3.5.
  • the adhesive buffer layer 2 is formed of, for example, a material such as SOG (Spin-On-Glass), a photosensitive resist material, or an ultraviolet curable resin, and adheres to the Si waveguide layer 1 and the magneto-optical material layer 3. It functions as an agent.
  • the adhesive buffer layer 2 has a refractive index of 2.8 or more and lower than the refractive index of the Si waveguide layer, specifically, a refractive index in the range of 2.8 or more and 3.4 or less.
  • the magneto-optical material layer 3 is formed of a magneto-optical material such as a rare earth magnetic garnet (hereinafter referred to as “magnetic garnet”) represented by a composition formula R 3 Fe 5 O 12 (R represents a rare earth element), for example. Functions as a cladding layer.
  • the magneto-optical material layer 3 is magnetized in a direction perpendicular to the light propagation direction of the rib waveguide 4 within the film surface so as to cause a non-reciprocal phase change in the light propagating through the rib waveguide 4.
  • the example shown in FIG. 1 is magnetized so that the magnetization directions are opposite in the portions corresponding to the two waveguides (waveguides 21 and 22 in FIG. 3).
  • the magneto-optical material layer 3 may be pre-magnetized, or the direction of magnetization of the magneto-optical material layer 3 is propagated on the magneto-optical material layer 3 as shown in FIGS.
  • Magnetic field applying means 5 (such as a pair of small permanent magnets) for applying a magnetic field from the outside may be provided to align the direction perpendicular to the direction.
  • the optical isolator 100 is multiplexed / demultiplexed by two tapered three-branch optical couplers, has two waveguides 21 and 22 between the two tapered three-branch optical couplers, and has a 90 ° reciprocal transition. It consists of a Mach-Zehnder interferometer including a phaser and a 90 ° nonreciprocal phase shifter.
  • the tapered three-branch optical coupler may be an optical branch coupler called a so-called Y branch.
  • the nonreciprocal phase shifter is realized by a layer structure of magneto-optical material / Si / SiO 2 . In such a structure, the magnetization of the magneto-optical material layer 3 is oriented in the film plane and perpendicular to the light propagation direction, thereby causing a nonreciprocal phase shift effect in the propagating TM mode light.
  • the nonreciprocal phase shifter is designed such that the difference in nonreciprocal phase change in the two waveguides 21 and 22 in the interferometer is 90 ° in the forward direction ( ⁇ 90 ° in the reverse direction).
  • Such a design adjusts each refractive index of the Si waveguide layer 1, the adhesive buffer layer 2, and the magneto-optical material layer 3, the direction of magnetization applied to each waveguide, the propagation length in which the light wave receives the magneto-optical effect, and the like. This can be realized.
  • the reciprocal phase shifter is realized by the optical path difference between the two waveguides in the interferometer, so that the difference in reciprocal phase change between the two waveguides 21 and 22 in the interferometer is ⁇ 90 °. Designed to.
  • the TM mode light incident on the port 11 is branched into light waves having the same amplitude and phase by the input end side tapered three-branch optical coupler, and each light wave propagates in the forward direction through the waveguide 21 and the waveguide 22, respectively.
  • the light wave propagating in the forward direction through the waveguide 21 and the waveguide 22 has a difference in phase change of 90 ° due to the nonreciprocal phase shift effect, but the difference is canceled out by the reciprocal phase shift effect of the same magnitude.
  • light waves propagating in the forward direction through the waveguide 21 and the waveguide 22 are incident on the output end side tapered three-branch optical coupler with the same amplitude and phase, and are coupled to the port 12 and output.
  • the TM mode light incident on the port 12 is branched into light waves having the same amplitude and the same phase by the output-end-side tapered three-branch optical coupler, and each light wave travels in the reverse direction through the waveguide 21 and the waveguide 22, respectively.
  • a light wave propagating in the opposite direction through the waveguide 21 and the waveguide 22 has a difference in phase change of ⁇ 90 ° due to the nonreciprocal phase shift effect, and further, a difference in phase change of ⁇ 90 ° due to the reciprocal phase shift effect Is done.
  • each light wave is coupled to and output from the port 13 and the port 14 instead of the port 11.
  • TM mode light incident from the port 11 is output from the port 12, but TM mode light incident from the port 12 is not output from the port 11, so that an isolator operation is obtained between the port 11 and the port 12. .
  • the waveguide pattern is transferred to the surface Si layer of the SOI substrate by photolithography, the rib waveguide 4 is formed by etching, and the Si waveguide layer 1 is formed.
  • Various conventional techniques can be used for photolithography and etching.
  • the adhesive buffer layer 2 is formed on the Si waveguide layer 1 including the rib waveguide 4 by using an adhesive material such as SOG, a photosensitive resist, or an ultraviolet curable resin.
  • an adhesive material such as SOG, a photosensitive resist, or an ultraviolet curable resin.
  • a conventional thin film forming technique such as spin coating or spraying can be used.
  • the adhesive buffer layer 2 may be formed by, for example, dropping.
  • the inventor of the present invention examined conditions that the adhesive buffer layer 2 should satisfy in order to suppress the decrease in the nonreciprocal phase shift effect while causing the adhesive buffer layer 2 to function as an adhesive.
  • the refractive index N of the adhesive buffer layer 2 needs to be lower than the refractive index of the Si waveguide layer 1.
  • the magnitude of the nonreciprocal phase shift effect [rad / mm] and the thickness of the adhesive buffer layer 2 was analyzed.
  • FIG. 4 shows the relationship obtained by the analysis.
  • the refractive index N of the adhesive buffer layer 2 is in the high range of 2.8 to 3.4, the nonreciprocal phase shift effect is increased with respect to the increase in the thickness of the adhesive buffer layer 2. It shows a tendency to decrease gradually in almost the same way.
  • the refractive index N of the adhesive buffer layer 2 is in the range of 2.8 to 3.4 and the thickness of the adhesive buffer layer 2 is 20 nm or less, the nonreciprocal phase shift effect is almost reduced. I understand that there is no.
  • the refractive index of the adhesive material such as SOG, photosensitive resist, and ultraviolet curable resin is 2.8 or more and lower than the refractive index of the Si waveguide layer 1 (preferably, The adhesive buffer layer 2 is formed using an adhesive material having a refractive index in the range of 2.8 to 3.4 so as to have a thickness of 20 nm or less.
  • a magneto-optical material that is magnetized in the direction perpendicular to the light propagation direction of the rib waveguide 4 within the film surface is bonded to the magneto-optical material layer 3.
  • a crystal grown on a suitable substrate for example, a magnetic garnet layer formed by liquid phase epitaxy on a single crystal substrate 4 made of garnet
  • this substrate is omitted.
  • the magneto-optical material layer 3 is magnetized so as to cause a nonreciprocal phase change in the light propagating through the rib waveguide 4 before or after bonding.
  • the optical isolator 100 includes the adhesive buffer layer 2 that functions as an adhesive between the Si waveguide layer 1 and the magneto-optical material layer 3.
  • the magneto-optical material layer 3 can be bonded firmly and with high reproducibility. Further, since there is no need to heat-treat the Si waveguide layer 1 and the magneto-optical material layer 3 by wafer bonding, the generation of cracks due to the heat treatment can be avoided. Furthermore, since the adhesive buffer layer 2 of the present embodiment has a refractive index of 2.8 or higher and lower than the refractive index of the Si waveguide layer 1, it is possible to suppress a decrease in the nonreciprocal phase shift effect.
  • the operation of the isolator 100 is not substantially affected.
  • the present invention is not limited to the above-described embodiment, and can be variously modified and applied.
  • the magneto-optical material layer 3 is formed only in the vicinity of the center of the rib waveguide 4 as an arrangement capable of causing non-reciprocal phase changes in the light propagating through the rib waveguide 4.
  • the magneto-optical material layer 3 may be formed so as to cover the entire rib waveguide 4.
  • the nonreciprocal phase shifter is designed so that the difference in nonreciprocal phase change between the two waveguides is 90 ° in the forward direction ( ⁇ 90 ° in the reverse direction).
  • the phase shifter is designed to be ⁇ 90 °, but these signs may be reversed.
  • an optical isolator is described as an example of an optical nonreciprocal element, but the present invention is not limited to an optical isolator.
  • an optical circulator utilizing a nonreciprocal phase shift effect can be configured.
  • the operation principle is the same as that of the optical isolator. That is, the non-reciprocal phase shift effect and the reciprocal phase shift effect cancel each other in the forward direction, and they are added together in the reverse direction, thereby realizing an optical circulator operation.
  • the configuration of the optical isolator is not limited to that shown in FIG.
  • the structure of the present invention in an optical isolator using a nonreciprocal waveguide mode-radiation mode conversion and having a Si waveguide layer having a linear rib waveguide, the structure of the present invention ( A structure in which an adhesive buffer layer is sandwiched between the Si waveguide layer and the magneto-optical material layer may be employed.
  • the optical isolator shown in FIG. 5A includes a non-reciprocal phase shifter having a layer structure of magneto-optical material / Si / SiO 2 magnetized in a direction perpendicular to the light propagation direction and at a predetermined angle with respect to the film surface.
  • the structure of the present invention in a TE-TM mode conversion type optical isolator having a linear Si waveguide layer, the structure of the present invention (between the Si waveguide layer and the magneto-optical material layer). You may employ
  • the optical isolator shown in FIG. 5B uses a nonreciprocal TE-TM mode converter realized by a layer structure of magneto-optical material / Si / SiO 2 magnetized in the light propagation direction, and an electro-optic effect. Reciprocal TE-TM mode converters realized using conventional technologies such as devices, devices using mode conversion in waveguides having a periodic asymmetric cross-section, devices using mode conversion by hybrid super mode, etc.
  • Both mode converters are each designed to generate a 45 ° mode conversion.
  • the light wave propagating in the forward direction is output in the same polarization state as that at the time of incidence because the non-reciprocal mode conversion of ⁇ 45 ° and the reciprocal mode conversion of 45 ° are cancelled.
  • the polarization state rotates 90 ° with respect to the incident time. Therefore, by providing a polarizer at each of the input end and the output end, it can function as an optical isolator.
  • FIG. 100 It is the figure which showed the structure of the optical isolator 100 which concerns on embodiment of this invention. It is a fragmentary sectional view of the optical isolator 100 shown in FIG. It is a figure which shows the rib waveguide 4 typically. It is a figure which shows the relationship between the magnitude

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Integrated Circuits (AREA)

Abstract

L'invention vise à proposer une nouvelle technologie consistant à assurer une adhésion suffisante entre une couche de Si et une couche de matériau magnéto-optique, tout en évitant la génération de craquelures dans le cas de la fabrication d'un dispositif optique non réciproque par liaison de la couche de Si avec un guide d'ondes à rebord formé et de la couche de matériau magnéto-optique. A cet effet, l'invention porte sur un dispositif optique non réciproque qui comporte une couche de guidage de Si qui est obtenue par la formation d'un guide d'ondes à rebord dans une couche de Si sur la surface d'un substrat silicium sur isolant (SOI), une couche de tampon adhésif qui est agencée sur la couche de guidage de Si et a un indice de réfraction de 2,8 ou plus et qui est inférieur à l'indice de réfraction de la couche de guidage de Si, et une couche de matériau magnéto-optique qui est agencée sur la couche de tampon adhésif pour donner une magnétisation dans la direction perpendiculaire à la direction de propagation de lumière du guide d'ondes à rebord.
PCT/JP2007/074864 2007-12-25 2007-12-25 Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque WO2009081487A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2007/074864 WO2009081487A1 (fr) 2007-12-25 2007-12-25 Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2007/074864 WO2009081487A1 (fr) 2007-12-25 2007-12-25 Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque

Publications (1)

Publication Number Publication Date
WO2009081487A1 true WO2009081487A1 (fr) 2009-07-02

Family

ID=40800805

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2007/074864 WO2009081487A1 (fr) 2007-12-25 2007-12-25 Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque

Country Status (1)

Country Link
WO (1) WO2009081487A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018041188A1 (fr) * 2016-08-31 2018-03-08 深圳大学 Guide d'ondes à faible perte sans fuite ayant un mode rapide au niveau de la surface magnétique d'un espace magnéto-optique de celui-ci et étant flexible de manière unidirectionnelle à n'importe quel angle
WO2018041175A1 (fr) * 2016-08-31 2018-03-08 深圳大学 Guide d'ondes courbé unidirectionnel à angle arbitraire à mode rapide à surface magnétique avec film mince magnéto-optique à faible perte d'étanchéité

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001350039A (ja) * 2000-06-06 2001-12-21 Tokyo Inst Of Technol 光アイソレータ及び光エレクトロニクス装置
JP2004240003A (ja) * 2003-02-04 2004-08-26 Rikogaku Shinkokai シリコン導波層を有する磁気光学導波路及びそれを用いた光非相反素子

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001350039A (ja) * 2000-06-06 2001-12-21 Tokyo Inst Of Technol 光アイソレータ及び光エレクトロニクス装置
JP2004240003A (ja) * 2003-02-04 2004-08-26 Rikogaku Shinkokai シリコン導波層を有する磁気光学導波路及びそれを用いた光非相反素子

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YOKOI H.: "Si-Dohaso o Yusuru Hikari- isolator", 2005 NEN THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS SOGO TAIKAI KOEN RONBUNSHU, ELECTRONICS SOCIETY C-3-52, 7 March 2005 (2005-03-07), pages 222 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018041188A1 (fr) * 2016-08-31 2018-03-08 深圳大学 Guide d'ondes à faible perte sans fuite ayant un mode rapide au niveau de la surface magnétique d'un espace magnéto-optique de celui-ci et étant flexible de manière unidirectionnelle à n'importe quel angle
WO2018041175A1 (fr) * 2016-08-31 2018-03-08 深圳大学 Guide d'ondes courbé unidirectionnel à angle arbitraire à mode rapide à surface magnétique avec film mince magnéto-optique à faible perte d'étanchéité

Similar Documents

Publication Publication Date Title
JP4456663B2 (ja) 光非相反素子製造方法
WO2010023738A1 (fr) Procédé de fabrication d'un dispositif optique non réciproque et dispositif optique non réciproque
Shoji et al. Magneto-optical isolator with silicon waveguides fabricated by direct bonding
US9164350B2 (en) Multi-port optical circulator system
KR100943847B1 (ko) 도파로형 광대역 광아이솔레이터
Takei et al. Design and simulation of silicon waveguide optical circulator employing nonreciprocal phase shift
Hutchings et al. Quasi-phase-matched faraday rotation in semiconductor waveguides with a magnetooptic cladding for monolithically integrated optical isolators
WO2019038477A1 (fr) Rotateur de faraday intégré
WO2009081488A1 (fr) Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque
Yan et al. On-chip nonreciprocal photonic devices based on hybrid integration of magneto-optical garnet thin films on silicon
WO2009081487A1 (fr) Dispositif optique non réciproque et procédé de fabrication du dispositif optique non réciproque
Shirato et al. High isolation in silicon waveguide optical isolator employing nonreciprocal phase shift
US20050089258A1 (en) Integrated optical isolator
JP5223092B2 (ja) 偏波無依存光アイソレータ
JP4171831B2 (ja) シリコン導波層を有する光非相反素子
JP2006309199A (ja) 光変調器
Mizumoto et al. Optical Nonreciprocal Devices Fabricated with Directly Bonded
Mizumoto et al. Optical nonreciprocal devices in silicon photonics
Yokoi et al. Interferometric optical isolator with air/Si/magnetic-garnet waveguide operated in unidirectional magnetic field
Fujie et al. Silicon waveguide optical isolator integrated with TE-TM mode converter
Chen et al. On-Chip Broadband, Compact TM Mode Mach–Zehnder Optical Isolator Based on InP-on-Insulator Platforms
Choowitsakunlert et al. Fabrication processes of magneto-optic waveguides with Si guiding layer for optical nonreciprocal devices
Yokoi et al. Interferometric optical isolator with Si guiding layer operated in unidirectional magnetic field
Ghosh et al. Demonstration of a Ce: YIG/SOI isolator bt BCB bonding
Yamaguchi et al. Proposal of Si Waveguide Optical Isolator Based on Nonreciprocal TE

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07860093

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07860093

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP