WO2003100516A1 - Dispositif et procede de conversion dynamique d'un point optique - Google Patents

Dispositif et procede de conversion dynamique d'un point optique Download PDF

Info

Publication number
WO2003100516A1
WO2003100516A1 PCT/IL2003/000446 IL0300446W WO03100516A1 WO 2003100516 A1 WO2003100516 A1 WO 2003100516A1 IL 0300446 W IL0300446 W IL 0300446W WO 03100516 A1 WO03100516 A1 WO 03100516A1
Authority
WO
WIPO (PCT)
Prior art keywords
waveguide
region
output
spot converter
signal
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/IL2003/000446
Other languages
English (en)
Inventor
Romanas Narevich
Yoav Berlatzky
Ilya Vorobeichik
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.)
Optun BVI Ltd
Original Assignee
Optun BVI Ltd
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 Optun BVI Ltd filed Critical Optun BVI Ltd
Priority to AU2003231890A priority Critical patent/AU2003231890A1/en
Publication of WO2003100516A1 publication Critical patent/WO2003100516A1/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 
    • G02F1/21—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
    • G02F1/225—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 in an optical waveguide structure
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/14—Mode converters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
    • G02B6/2852—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using tapping light guides arranged sidewardly, e.g. in a non-parallel relationship with respect to the bus light guides (light extraction or launching through cladding, with or without surface discontinuities, bent structures)
    • 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
    • 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 
    • G02F1/0147—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 thermo-optic effects
    • 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
    • G02F1/29—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 position or the direction of light beams, i.e. deflection
    • G02F1/31—Digital deflection, i.e. optical switching
    • G02F1/313—Digital deflection, i.e. optical switching in an optical waveguide structure
    • G02F1/3132—Digital deflection, i.e. optical switching in an optical waveguide structure of directional coupler type
    • 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
    • G02F1/29—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 position or the direction of light beams, i.e. deflection
    • G02F1/31—Digital deflection, i.e. optical switching
    • G02F1/313—Digital deflection, i.e. optical switching in an optical waveguide structure
    • G02F1/3137—Digital deflection, i.e. optical switching in an optical waveguide structure with intersecting or branching waveguides, e.g. X-switches and Y-junctions
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B2006/12083—Constructional arrangements
    • G02B2006/121—Channel; buried or the like
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/264—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting
    • G02B6/266—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting the optical element being an attenuator
    • 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
    • G02F2201/12—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 electrode
    • 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
    • G02F2203/00—Function characteristic
    • G02F2203/48—Variable attenuator
    • 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
    • G02F2203/00—Function characteristic
    • G02F2203/58—Multi-wavelength, e.g. operation of the device at a plurality of wavelengths
    • G02F2203/585—Add/drop devices

Definitions

  • the present invention relates generally to the field of optical devices and, more specifically, to localization of a signal of light.
  • a spot-size converter for converting the shape, e.g. the size and physical location, of a light signal within a waveguide.
  • U.S. Patent No. 5,623,566 to Hyung J. Lee et al describes a device using a thin film heating element to create a thermally induced light-guide.
  • a heating element When the heating element is inactive, a light signal may not propagate through the light- guide.
  • the heating element When the heating element is activated, the heat induced in the light-guide changes its optical properties, i.e. its index of refraction, such that the light signal may propagate through the heat-induced waveguide.
  • a device including N heating elements associated with N light-guides connected to N outputs may allow directing a light signal to a desired output by activating the heating element corresponding to the desired output.
  • a drawback of this device is the high heating element temperature required in order to achieve even a low power extinction ratio between the signals at the output ports.
  • a dynamic, adiabatic optical spot converter which may include an adiabatically shaped, e.g., tapered, waveguide associated with at least one control element, e.g., a heating element in thermal communication with at least one, respective, region of the waveguide.
  • the waveguide may have a cross-sectional structure including a core surrounded by a cladding, and an optional base substrate to support the waveguide and/or to assist in maintaining a desired waveguide temperature.
  • the spot converter may include at least two states of operation, e.g., at least one "On” state, and an "Off" state.
  • a light signal with a wavelength, ⁇ entering the input may propagate through the waveguide and exit the waveguide without undergoing any conversion.
  • at least one of the control elements may be activated to localize at least a fraction of at least one mode of the light signal to at least one, respective, region of the waveguide, respectively, and the at least one localized signal may exit the waveguide from at least one, respective, output location at an output of the spot converter.
  • the at least one control element may be positioned such that different localized signals may exit the spot converter from different output locations.
  • the at least one heating element may be selectively and/or controllably activated to localize a predetermined fraction of the signal to predetermined output locations.
  • the more electrical power is supplied to the at least one heating element the higher temperature increase is produced, and the more localized the converted signal may be, i.e., the signal may be directed to a narrower region of the waveguide and, thus, a narrower output location.
  • the waveguide may have a tapered structure including an output width, w t , and a length, L, such that:
  • the spot converter may be implemented as a switching device.
  • a 1X2 switch may include two states of operation, e.g., "first output” and "second output".
  • a first control element may be activated to localize at least a fraction of a first mode of the input signal to a first region determined by the position of the first control element.
  • the at least partially localized first mode of the input signal may exit the waveguide at a first output location determined by the position of the first control element.
  • a second control element When the switch is set to the "second output" state, a second control element may be activated to localize at least a fraction of a second mode of the input signal to a second region determined by the position of the second control element.
  • the at least partially localized second mode of the input signal may exit the waveguide at a second output location determined by the position of the second control element.
  • the first and second control elements may be controllably and/or selectively activated such that a desired fraction of either or both modes of the input signal may be localized to either or both the first and second output locations.
  • the 1X2 switch may be implemented as a variable optical attenuator (VOA) by using only one of the switch output locations and both of the control elements.
  • VOA variable optical attenuator
  • the control element corresponding to the unused output location may be activated to localize a predetermined fraction of the input signal to the unused output location.
  • FIG. 1 is a schematic, front-view cross-sectional, illustration of a waveguide in accordance with exemplary embodiments of the invention
  • FIG. 2 is a schematic illustration of a graph depicting effective refractive index versus horizontal location and heating element temperature, respectively, in the waveguide of Fig. 1;
  • FIG. 3 is a schematic illustration of a graph depicting lowest order signal power versus horizontal location and heating element temperature, respectively, in the waveguide of Fig. 1 ;
  • FIG. 4 is a schematic, top view, illustration of a spot converter in accordance with exemplary embodiments of the invention.
  • FIG. 5 is a schematic, top view, illustration of a 1X2 switch in accordance with exemplary implementations of the present invention.
  • Fig. 6 is a schematic illustration of a graph depicting extinction ratio versus temperature increase for the device of Fig. 5.
  • FIG. 1 schematically illustrates a cross- section of a waveguide 100 in accordance with exemplary embodiments of the invention.
  • Waveguide 100 may include a core 102 surrounded by a cladding 104.
  • Waveguide 100 may also include a base substrate 106 attached to a surface, e.g., a bottom surface, of cladding 104, and a control element, e.g., a heating element 108, in thermal communication with a surface, e.g., a top surface, of cladding 106.
  • a control element e.g., a heating element 108
  • core 102 may be formed of a silica-based material having a core refractive index, n co.e , of about 1.455.
  • cladding 104 may be formed of a silica-based material having a cladding refractive index, n c iadding, of about 1.445.
  • core 102 may have a core height, h, of between 2 ⁇ m and 15 ⁇ m, for example, about 6 ⁇ m, and a width, w, of between 10 ⁇ m and 200 ⁇ m, for example, 100 ⁇ m.
  • heating element 108 may have a width, w e , of between 10 ⁇ m and 50 ⁇ m, for example, between 11 ⁇ m and 17 ⁇ m. Furthermore, according to exemplary embodiments of the invention, a distance, H, between core 102 and heating element 108 may be between 10 ⁇ m and 30 ⁇ m, for example, 16 ⁇ m.
  • Base substrate 106 may be formed of any suitable material known in the art, for example, silicon. Base substrate 106 may be maintained at a substantially constant temperature by use of a Thermo- Electric Cooler (TEC) or any other device adapted to keep the substrate at a substantially constant temperature, e.g., room temperature.
  • Heating element 108 may be implemented in the form of an electrode, for example, a strip of material having a suitable electrical resistance capable of producing a predetermined increase in temperature in response to electrical power supplied thereto.
  • waveguide 100 may have a cross-section aspect ratio such that the width, w, of the waveguide may be much larger than the height, h, of the waveguide.
  • This cross-section may result in a waveguide that is sufficiently narrow in height to support only one mode order in the vertical, y, dimension and sufficiently wide to support several mode orders in a horizontal, x, dimension.
  • These dimensions may be calculated using approximation methods, for example, the approximation described in paragraph 2.4 of chapter two of K. Okamoto "Fundamentals of Optical Waveguides", San Diego, Academic Press (1992), which is incorporated herein by reference in its entirety.
  • the aspect ratio of the spot converter, AR may be defined by the following equation:
  • the approximation method may be further used to compute an effective refractive index, n er. (x, ⁇ T), as a function of horizontal location in the waveguide, x, and temperature increase, ⁇ T, between heating element 108 and ambient temperature.
  • the effective refractive index approximation may depend on two assumptions.
  • the first assumption is that a temperature-induced refractive index change, which may be defined by the difference between n eff (x, ⁇ T) and n CO r e , is significantly smaller than the difference, ⁇ n, between n cor e and n c ia d ding, such that the light signal may be confined in the y direction, as described above.
  • the second assumption is that the temperature-induced refractive index does not vary substantially along the waveguide height.
  • the temperature-induced refractive index does not vary substantially along the waveguide height.
  • thermo-optical coefficient, dn/dT, for glass is about 1.15-e " . Therefore, the thermo-optical coefficient, dn/dT, for glass is about 1.15-e " . Therefore, the thermo-optical coefficient, dn/dT, for glass is about 1.15-e " . Therefore, the thermo-optical coefficient, dn/dT, for glass is about 1.15-e " . Therefore, the thermo-optical coefficient, dn/dT, for glass is about 1.15-e " . Therefore, the
  • ⁇ n significantly smaller than ⁇ n, which may be equal to about 0.01.
  • a temperature distribution in waveguide 100 resulting from activation of heating element 108 may be calculated as a stationary solution of a two-dimensional heat equation with a boundary condition, e.g., requiring a zero temperature increase at the surface of the base substrate.
  • a boundary condition e.g., requiring a zero temperature increase at the surface of the base substrate.
  • Equation 2 may be applied to a waveguide having the dimensions H and w e and a thermal conductivity of the core and the cladding in accordance with embodiments of the invention, for example, a thermal conductivity of approximately for silica.
  • Parameter p in Equation 2 is the electric power density that may be supplied to the at least one heating element of the device.
  • the temperature distribution in waveguide 100 may be used to calculate the refractive index, n ⁇ ff (x, ⁇ T), as a function of x and ⁇ T, for example, using the thermo-optical coefficient dn7dT described above, i.e. multiplying dn7dT with each one of the ⁇ T values, respectively, to obtain a variation of n ⁇ ff created by each one of the ⁇ T values, respectively.
  • Fig. 2 is a schematic illustration of a graph depicting n ⁇ ff (x, ⁇ T) versus x and ⁇ T for the waveguide of Fig. 1.
  • electric power of about 0 Watts (W), 2.6W, and 5.1W, respectively, may be supplied to the heating element, in order to produce isothermal lines 202, 204 and 206 of Fig. 2, respectively.
  • a maximum effective refractive index, N( ⁇ T), may be defined for each temperature increase value, ⁇ T, as follows:
  • N( ⁇ T) may alternatively be defined by:
  • the material In order to allow a given mode to propagate through a given material, the material should have a modal effective refractive index, n ef m > as follows:
  • a free space wave vector, k may be defined by:
  • modal effective refractive index may be required to allow propagation of different modes.
  • the modal effective refractive index may also depend on attributes of the waveguide, e.g., waveguide geometry and/or refractive indices, as well as on signal attributes, e.g., wavelength.
  • Equation 8 may be rewritten as follows:
  • ⁇ n( ⁇ T) is a temperature-induced change, which may be defined by:
  • Equation 10 [0055] Substituting Equation 10 in Equation 5 results in the following new equation:
  • Equation 7 Substituting Equation 7 in Equation 12 and re-arranging equation 12 yields the following equation:
  • Equation 13 may be used to calculate a minimum required temperature-induced change. Based on the calculated minimum temperature-induced change, the relationship illustrated by the graph of Fig. 2 may be used to find a corresponding minimal ⁇ T allowing to localize a mode, e.g., a lowest order mode, i.e., the eigenmode of the waveguide, to a region of the waveguide, as described herein.
  • a mode e.g., a lowest order mode, i.e., the eigenmode of the waveguide
  • a combination of ⁇ T and w satisfying Equation 13 may be chosen to allow localization of the eigenmode to a predetermined region of the waveguide. If, for example, a given combination of ⁇ T and w does not satisfy Equation 13, then the eigenmode may not be localized.
  • n ef. (x, ⁇ T) may be used to numerically compute the signal power of the lowest-order mode along the x-axis of the waveguide, for example, by substituting n eff (x, ⁇ T) and solving for E in the following modal equation:
  • E is an amplitude of a modal signal field, and wherein the power of the signal may be proportional to E 2 .
  • Fig. 3 is a schematic illustration of a graph depicting eigenmode signal power versus horizontal location and heating element temperature, respectively, in the waveguide of Fig. 1.
  • a predetermined temperature increase which may be produced as described above, may be used to localize a mode of a signal to a region of the waveguide substantially underneath heating element 108 (Fig. 1).
  • heating element 108 may be controllably activated to localize the signal.
  • the more electrical power is supplied to the heating element the higher temperature increase is produced, and the more localized the signal may be, i.e., the signal may be localized to a narrower region of the waveguide.
  • FIG. 4 schematically illustrates a top view of a dynamic, adiabatic spot converter 400 in accordance with exemplary embodiments of the invention.
  • spot converter 400 may include an adiabatic waveguide 410, having an input 402and an output 404, and at least one control element, e.g., heating element 408, in thermal communication with a top surface of waveguide 410.
  • the parameters for designing the tapered structure of waveguide 410 may be selected as described in detail herein.
  • adiabatic waveguide 410 may have a cross-sectional structure similar to the one illustrated in Fig. 1 and as described above.
  • spot converter 400 may have at least two states of operation, e.g., at least one "On” state, and an "Off” state.
  • a light signal entering input 402 may propagate through adiabatic waveguide 410 and exit output 404 without undergoing any conversion.
  • the spot converter is at the "On” states, by controllably activating the at least one heating element 408, at least a fraction of a mode of the light signal may be localized to a region substantially underneath heating element 408.
  • the localized light signal may propagate through output 404 at an output spot 406. Consequently, the at least partly localized mode of the light signal may exit spot converter 400 at an output location 412 of output 404.
  • spot converter 400 may include several heating elements 408, which may be used to localize at least a fraction of predetermined modes of the light signal to regions substantially underneath several respective heating elements, which localized signal fractions may exit spot converter 400 at several desired output locations of output 404, as described above.
  • waveguide 410 may be adapted to adiabatically localize at least the fraction of the signal, as described below.
  • adiabatic localizing means a substantially small part of the signal power is lost during the localization by virtue of a gradual, controlled, conversion process.
  • the adiabatic localization in accordance with embodiments of the invention is achieved, inter alia, by the specific tapered structure of the waveguide as described herein.
  • a minimum waveguide tapering length, L may be required in order to significantly reduce the transfer of signal power between the localized mode and other modes of the waveguide, i.e., to avoid cross talk between different channels.
  • a minimal length L may be required to allow a gradual increase in the waveguide width such that the signal power loss would be minimal.
  • the required tapered section length may be computed for a taper end-width, w t , by the following equation:
  • Equation 15 may be valid for the same limit as that of Equation 6 above.
  • waveguide 410 may have a width, w t , of between 60 ⁇ m and 150 ⁇ m, for example, 100 ⁇ m, for a wavelength, ⁇ , of about 1.55 ⁇ m. According to these embodiments, in order to satisfy equation 15, waveguide 410 may have a length of at least 6452 ⁇ m, for example, 10mm.
  • Fig. 5 schematically illustrates a top view of a 1X2 switch 500 in accordance with exemplary implementations of the present invention.
  • switch 500 may include an adiabatic waveguide 504 having an input 502, a first output port 508, and a second output port 510.
  • Switch 500 may further include a first control element, e.g., a heating element 505, and a second control element, e.g., a heating element 506.
  • Switch 500 may also include a first output taper 511 and a second output taper 512 connecting portions of waveguide 504 to output ports 508 and 510, respectively.
  • waveguide 504 may be adapted to adiabatically localize at least a fraction of at least one mode of an input signal to at least one region of the waveguide, respectively, as described above.
  • switch 500 may have two states of operation, e.g., a "first output” state and "second output” state.
  • first heating element 505 may be activated to localize at least a fraction of a first mode of the input signal to a first region substantially underneath heating element 505, in analogy to device 400 described above with reference to Fig. 4.
  • This first localized signal may propagate through a first output spot 513 of waveguide 504, substantially underneath first heating element 505, and may be coupled by first output taper 511 to output port 508.
  • second heating element 506 may be activated to localize at least a fraction of a second mode of the input signal to a second region substantially underneath heating element 506, in analogy to device 400 described above with reference to Fig. 4.
  • This second localized signal may propagate through a second output spot 514 of the waveguide, substantially underneath the second heating element, and may be coupled by second output taper 512 to output port 510.
  • the first and second heating elements may be controllably activated such that a desired fraction of a desired mode of the input signal may be localized to either output ports 508 or 510, as described above. If neither of the heating elements is activated, all modes of the input signal may exit both output ports.
  • waveguide 504 may have a tapered structure with a length, L, of between 5mm and 15mm, for example 10mm, a distance, W , between centers of outputs 508 and 510 of between 55 ⁇ m and 65 ⁇ m, for example 60 ⁇ m, an output taper length of between 0.5mm and 2mm, for example, 1 mm, a heating element width, w e , of between 10 ⁇ m and 20 ⁇ m, for example, 10 ⁇ m, and taper width, w t , of between 50 ⁇ m and 150 ⁇ m, for example, 100 ⁇ m.
  • switch 500 may be implemented as a variable optical attenuator (VOA) by using only one of the switch outputs, for example, output port 508, and both of heating elements 505 and 506.
  • VOA variable optical attenuator
  • control element 506 may be activated to localize a predetermined fraction of the input signal to the unused output port 510, which may be disconnected.
  • Fig. 6 schematically illustrates a graph depicting extinction ratio versus ⁇ T for the device of Fig. 5.
  • the extinction ratio may be defined as the ratio between signal power in first output port 508 and signal power in second output 510 when switch 500 is set to the "first output" state, as described above.
  • an extinction ratio of about 35dB may be achieved by activating first heating element 505 to produce a ⁇ T of about 100 degrees, as shown in Fig. 6. It will be appreciated by persons skilled in the art that this extinction ratio is significantly higher than the extinction ratio that may be achieved by prior art switches and spot converters under comparable operational conditions.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Optical Integrated Circuits (AREA)
  • Optical Communication System (AREA)

Abstract

Un convertisseur dynamique d'un point adiabatique comportant un guide d'onde adiabatique permet de diriger adiabatiquement au moins une fraction d'au moins un mode d'un signal d'entrée pour le propager dans au moins une région respective du guide d'onde et le sortir d'au moins un emplacement de sortie respectif du guide d'onde.
PCT/IL2003/000446 2002-05-28 2003-05-28 Dispositif et procede de conversion dynamique d'un point optique Ceased WO2003100516A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003231890A AU2003231890A1 (en) 2002-05-28 2003-05-28 Device and method of dynamic optical spot conversion

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US38332602P 2002-05-28 2002-05-28
US38332502P 2002-05-28 2002-05-28
US60/383,325 2002-05-28
US60/383,326 2002-05-28

Publications (1)

Publication Number Publication Date
WO2003100516A1 true WO2003100516A1 (fr) 2003-12-04

Family

ID=29587002

Family Applications (5)

Application Number Title Priority Date Filing Date
PCT/IL2003/000444 Ceased WO2003100485A2 (fr) 2002-05-28 2003-05-28 Procede et dispositif de commutation optique et d'attenuation optique variable
PCT/IL2003/000446 Ceased WO2003100516A1 (fr) 2002-05-28 2003-05-28 Dispositif et procede de conversion dynamique d'un point optique
PCT/IL2003/000445 Ceased WO2003100506A1 (fr) 2002-05-28 2003-05-28 Procede et appareil de conversion de mode optique
PCT/IL2003/000447 Ceased WO2003100507A1 (fr) 2002-05-28 2003-05-28 Dispositif de guides optiques induits
PCT/IL2003/000443 Ceased WO2003100490A1 (fr) 2002-05-28 2003-05-28 Procede et dispositif de multiplexage et de demultiplexage par division de mode optique

Family Applications Before (1)

Application Number Title Priority Date Filing Date
PCT/IL2003/000444 Ceased WO2003100485A2 (fr) 2002-05-28 2003-05-28 Procede et dispositif de commutation optique et d'attenuation optique variable

Family Applications After (3)

Application Number Title Priority Date Filing Date
PCT/IL2003/000445 Ceased WO2003100506A1 (fr) 2002-05-28 2003-05-28 Procede et appareil de conversion de mode optique
PCT/IL2003/000447 Ceased WO2003100507A1 (fr) 2002-05-28 2003-05-28 Dispositif de guides optiques induits
PCT/IL2003/000443 Ceased WO2003100490A1 (fr) 2002-05-28 2003-05-28 Procede et dispositif de multiplexage et de demultiplexage par division de mode optique

Country Status (3)

Country Link
JP (2) JP2004157506A (fr)
AU (5) AU2003231349A1 (fr)
WO (5) WO2003100485A2 (fr)

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7321705B2 (en) 2002-05-28 2008-01-22 Optun (Bvi) Ltd. Method and device for optical switching and variable optical attenuation
EP1624325B1 (fr) 2004-08-03 2013-05-22 STMicroelectronics Srl Structure optique intégrée, sensible à l'énergie rayonnée dans la gaine d'un circuit optique planaire
JP5287885B2 (ja) * 2005-12-09 2013-09-11 富士通株式会社 光導波路を伝搬する光と回折格子とを結合させた光素子
JP2012194362A (ja) * 2011-03-16 2012-10-11 Nippon Telegr & Teleph Corp <Ntt> モード合分波カプラ及びその製造方法
JP5773521B2 (ja) * 2011-08-03 2015-09-02 日本電信電話株式会社 モード合分波器、光送受信装置及び光通信システム
GB2496833A (en) * 2011-08-04 2013-05-29 Phoenix Photonics Ltd Mode-selective launching and detecting in an optical waveguide
JP2013257354A (ja) * 2012-06-11 2013-12-26 Nippon Telegr & Teleph Corp <Ntt> モード合分波器、光送受信装置及び光通信システム
JP5548241B2 (ja) * 2012-07-24 2014-07-16 日本電信電話株式会社 光合分波器
JP6245651B2 (ja) 2012-08-27 2017-12-20 国立大学法人九州大学 モード間光スイッチ
JP5988100B2 (ja) * 2012-12-14 2016-09-07 日本電信電話株式会社 モード合分波器
JP5842277B2 (ja) * 2013-02-04 2016-01-13 日本電信電話株式会社 モード合分波器及びその設計方法
US8873899B2 (en) * 2013-03-14 2014-10-28 Cisco Technology, Inc. Modal rotation in optical waveguides
JP6288772B2 (ja) * 2013-06-18 2018-03-07 日本電信電話株式会社 モード合分波器及びモード多重通信システム
US20150104130A1 (en) * 2013-10-14 2015-04-16 Cisco Technology, Inc. Optical power splitter
JP6242662B2 (ja) * 2013-11-06 2017-12-06 株式会社フジクラ モード変換素子及び光導波路素子
JP6312198B2 (ja) * 2013-12-20 2018-04-18 Kddi株式会社 光合波装置および光分波装置
JP6473739B2 (ja) * 2014-03-03 2019-02-20 国立大学法人横浜国立大学 モード合分波器
US9322997B2 (en) * 2014-03-25 2016-04-26 Seagate Technology Llc Branched waveguide configuration
WO2016070420A1 (fr) 2014-11-07 2016-05-12 华为技术有限公司 Convertisseur de mode, et appareil et procédé d'émission avec guides d'ondes multimodes
GB201516759D0 (en) * 2015-09-22 2015-11-04 Univ Aston Mode division multiplexed passive optical network
JP2023044916A (ja) * 2021-09-21 2023-04-03 沖電気工業株式会社 光デバイス

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5623566A (en) * 1995-05-19 1997-04-22 Lucent Technologies Inc. Network with thermally induced waveguide
JP2000241838A (ja) * 1999-02-18 2000-09-08 Nippon Telegr & Teleph Corp <Ntt> デジタル熱光学光スイッチ
US6222953B1 (en) * 1997-01-23 2001-04-24 Jds Uniphase Photonics C.V. Thermo-optical switch provided with a laterally shifted element

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2549240A1 (fr) * 1983-07-15 1985-01-18 American Telephone & Telegraph Reseau de distribution local a acces multiples
JPS6051822A (ja) * 1983-08-31 1985-03-23 Yokogawa Hokushin Electric Corp 光制御素子
US4828350A (en) * 1986-01-17 1989-05-09 The Board Of Trustees Of The Leland Stanford Junior University Fiber optic mode selector
JP2566923B2 (ja) * 1986-06-18 1996-12-25 富士通株式会社 光スイツチ
US4915468A (en) * 1987-02-20 1990-04-10 The Board Of Trustees Of The Leland Stanford Junior University Apparatus using two-mode optical waveguide with non-circular core
US5048907A (en) * 1990-02-23 1991-09-17 Amoco Corporation Electric field induced quantum well waveguides
JP2902082B2 (ja) * 1990-08-30 1999-06-07 沖電気工業株式会社 光波長フィルタ及びその駆動方法
NL9200328A (nl) * 1992-02-21 1993-09-16 Nederland Ptt Optische schakelcomponent.
JPH08254674A (ja) * 1995-03-17 1996-10-01 Fujitsu Ltd 光機能デバイス
DE19653744A1 (de) * 1996-12-20 1998-06-25 Alsthom Cge Alcatel Herstellungsverfahren für einen modenselektiven Verschmelzkoppler
SE521765C2 (sv) * 1997-08-29 2003-12-02 Ericsson Telefon Ab L M Anordning och förfarande relaterande till optisk transmission
US6292597B1 (en) * 1999-01-11 2001-09-18 Jds Fitel Inc. N×N non-blocking optical switch
KR100358418B1 (ko) * 2000-02-28 2002-10-25 한국과학기술원 용융형 모드분할 방향성 결합기의 제조방법
KR100350413B1 (ko) * 2000-10-02 2002-08-28 (주)젠포토닉스 외부 조절이 가능한 광도파로형 고차모드 발생기

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5623566A (en) * 1995-05-19 1997-04-22 Lucent Technologies Inc. Network with thermally induced waveguide
US6222953B1 (en) * 1997-01-23 2001-04-24 Jds Uniphase Photonics C.V. Thermo-optical switch provided with a laterally shifted element
JP2000241838A (ja) * 1999-02-18 2000-09-08 Nippon Telegr & Teleph Corp <Ntt> デジタル熱光学光スイッチ

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
KLEIN-KOERKAMP M M ET AL: "DESIGN AND FABRICATION OF A PIGTAILED THERMO-OPTIC 1X2 SWITCH", PROCEEDINGS INTEGRATED PHOTONICS RESEARCH, XX, XX, vol. 3, 1994, pages 274 - 276, XP002040422 *
PATENT ABSTRACTS OF JAPAN vol. 2000, no. 12 3 January 2001 (2001-01-03) *
SEKERKA-BAJBUS M A ET AL: "Design optimization and implementation of an optical Ti:LiNbO3 3-branch switch by the beam propagation method", INTEGRATED OPTICS & OPTOELECTRONICS PROCEEDINGS, 5-8 SEPT. 1989, BOSTON, BELLINGHAM, WA, US, vol. 1177, 5 September 1989 (1989-09-05), pages 216 - 227, XP000391618 *
WANG W-K ET AL: "PLANAR SILICA-GLASS OPTICAL WAVEGUIDES WITH THERMALLY INDUCED LATERAL MODE CONFINEMENT", JOURNAL OF LIGHTWAVE TECHNOLOGY, IEEE. NEW YORK, US, vol. 14, no. 3, 1 March 1996 (1996-03-01), pages 429 - 436, XP000586132, ISSN: 0733-8724 *

Also Published As

Publication number Publication date
AU2003231890A1 (en) 2003-12-12
WO2003100490A1 (fr) 2003-12-04
JP2004163874A (ja) 2004-06-10
AU2003233163A8 (en) 2003-12-12
JP2004157506A (ja) 2004-06-03
WO2003100485A3 (fr) 2004-02-19
AU2003228087A1 (en) 2003-12-12
AU2003233163A1 (en) 2003-12-12
AU2003231350A1 (en) 2003-12-12
WO2003100485A2 (fr) 2003-12-04
WO2003100507A1 (fr) 2003-12-04
WO2003100506A1 (fr) 2003-12-04
AU2003231349A1 (en) 2003-12-12

Similar Documents

Publication Publication Date Title
WO2003100516A1 (fr) Dispositif et procede de conversion dynamique d&#39;un point optique
US5418868A (en) Thermally activated optical switch
Wang et al. Optical switch based on multimode interference coupler
US6240226B1 (en) Polymer material and method for optical switching and modulation
Lai et al. Low-power compact 2× 2 thermooptic silica-on-silicon waveguide switch with fast response
Noh et al. Polymer waveguide variable optical attenuator and its reliability
EP0987580A1 (fr) Modulateur d&#39;intensité lumineuse et commutateur le comprenant
US6246809B1 (en) Asymmetric thermo-optical switch
Liu et al. Two-dimensional design and analysis of trench-coupler based Silicon Mach-Zehnder thermo-optic switch
US5623566A (en) Network with thermally induced waveguide
Wang et al. Planar silica-glass optical waveguides with thermally induced lateral mode confinement
JP4934614B2 (ja) 熱光学位相シフタ
Han et al. 2$\,\times\, $2 Polymer Thermo-Optic Digital Optical Switch Using Total-Internal-Reflection in Bend-Free Waveguides
JP2003228031A (ja) 光回路部品
JPWO2002023264A1 (ja) 光デバイス
Wu et al. Design optimization for micromachined low power Mach-Zehnder thermo-optic switch
Dwivedi et al. An ultra-low-loss compact phase-change material-based hybrid-mode interferometer for photonic memories
JP2000206476A (ja) 温度制御型光導波路
US6671439B2 (en) Integrated waveguide arrangement, process for producing an integrated waveguide arrangement, and waveguide components
JP2006259104A (ja) 光回路及び導波路型光可変減衰器
JP4899393B2 (ja) 導波路型可変光減衰器
EP4555377B1 (fr) Atténuateur optique variable
JP2004286830A (ja) 導波路型光可変減衰器
JP2020106608A (ja) 光信号処理装置および光信号処理装置の製造方法
KR100237187B1 (ko) 편광 독립 가변 광 감쇄기

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PH PL PT RO RU SC SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: JP