WO1998035250A1 - A tapered rib waveguide - Google Patents

A tapered rib waveguide Download PDF

Info

Publication number
WO1998035250A1
WO1998035250A1 PCT/GB1998/000384 GB9800384W WO9835250A1 WO 1998035250 A1 WO1998035250 A1 WO 1998035250A1 GB 9800384 W GB9800384 W GB 9800384W WO 9835250 A1 WO9835250 A1 WO 9835250A1
Authority
WO
WIPO (PCT)
Prior art keywords
waveguide
tapered
mode
smaller
tapered rib
Prior art date
Application number
PCT/GB1998/000384
Other languages
French (fr)
Inventor
Andrew George Rickman
Arnold Peter Roscoe Harpin
Robin Jeremy Richard Morris
Mehdi Asghari
Original Assignee
Bookham Technology Limited
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 Bookham Technology Limited filed Critical Bookham Technology Limited
Priority to DE69802948T priority Critical patent/DE69802948T2/en
Priority to AU59982/98A priority patent/AU5998298A/en
Priority to JP53400798A priority patent/JP2001510589A/en
Priority to EP98903157A priority patent/EP1015922B1/en
Priority to CA002274176A priority patent/CA2274176A1/en
Publication of WO1998035250A1 publication Critical patent/WO1998035250A1/en

Links

Classifications

    • 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
    • G02B6/122—Basic optical elements, e.g. light-guiding paths
    • G02B6/1228—Tapered waveguides, e.g. integrated spot-size transformers
    • 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
    • G02B2006/12097—Ridge, rib or the like

Definitions

  • This invention relates to a tapered rib waveguide providing a transition from an optical waveguide of relatively large cross-section to an optical waveguide of smaller cross-section
  • An integrated optical circuit employs optical waveguides to transmit light around the circuit and to connect to external optical waveguides such as optical fibres
  • the integrated optical waveguides and/or optical fibres may be of different cross-sectional size so there is a need for means to provide a transition from a waveguide of relatively large cross-section to a waveguide of smaller cross-section
  • a variety of devices have been proposed for this purpose but they tend to be relatively complex and/or difficult to fabricate
  • This invention aims to provide a tapered rib waveguide which is of relatively simple construction is relatively easy to fabricate and which provides a low- loss transition from a large cross-section to a smaller cross-section
  • a tapered rib waveguide tapering from a large multi-mode optical waveguide to a smaller, single-mode optical waveguide
  • the tapered rib waveguide comprising at least two portions formed of the same material a lower portion which tapers laterally from the large waveguide to the smaller waveguide and an upper portion, formed on the lower portion, which tapers to a point or other form of termination the dimensions of the two portions being arranged such that substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller single-mode waveguide
  • Figure 1 shows a perspective view of a preferred embodiment of a tapered rib waveguide according to the invention
  • Figure 2A is a schematic plan view of another embodiment of a tapered rib waveguide according to the invention and Figure 2B a cross-section thereof, and
  • Figures 3A and 3B 4A and 4B, and 5A and 5B show schematic plan and side views of three further embodiments of a tapered rib waveguide according to the invention
  • the drawing shows a tapered rib waveguide tapering from a large multi-mode waveguide about 10 microns x 10 microns to a smaller single-mode waveguide about 4 3 microns x 4 microns
  • the illustrated waveguides are in the form of ribs formed on the upper surface of a silicon layer, e g of a silicon-on-insulator chip
  • the silicon-on-insulator chip is preferably manufactured from conventional wafers such as those used in Very Large Scale Integration (VSLI) electronic circuits
  • VSLI Very Large Scale Integration
  • the drawing shows the rib waveguides formed in the silicon layer 1 of such a chip and shows the oxide layer 2 separating the silicon layer 1 from a silicon substrate 3
  • a silicon dioxide cladding (not shown) is also usually provided
  • the tapered rib waveguide shown in the drawing comprises two portions a lower portion 4 which tapers laterally from a width of about 10 microns to a width of about 4 microns over a length of about 1000 microns, and an upper portion 5, formed on the lower portion 4, which tapers from a width of about 10 microns to a point over a length of about 800 microns
  • the upper portion 5 thus tapers more rapidly than the lower portion 4 and in the embodiment shown has a triangular wedge-like shape when viewed from above Both portions are, however, designed to provide a substantially adiabatic taper
  • both the upper and lower portions 5 and 4 taper at the same angle so the sides of the two portions are parallel to each other In this case, the wide end of the upper portion 5 is narrower than the wide end of the lower portion 4
  • the upper and lower portions 5 and 4 preferably taper at an angle (with respect to the axis of the waveguide) of less than 1 degree and preferably less than 0 5 of a degree Such a gradual taper ensures that any losses caused by the taper are kept small
  • the upper portion 4 tapers to a point or to some other form of termination In the arrangement shown in Figure 1 , the tapering section of the upper portion 5 is formed on top of the tapering section of the lower portion 4
  • the two portions 4 and 5 including the input facet 6, can be formed together by conventional lithography and dry etching as they are defined by vertical surfaces They are formed of the same material and thus have the same refractive index
  • the two portions may be formed homogenously on the chip Alternatively, the upper portion 5 may be formed separately and mounted on the lower portion 4
  • the upper faces of the upper and lower portions 4 and 5 are substantially parallel to the plane of the chip i e the upper and lower portions 4 and 5 each have a substantially constant height above the surface of the chip (7 2 and 1 5 microns respectively, in the illustrated example)
  • the tapered rib waveguide shown in the drawing thus provides a two- dimensional taper, the taper in the lateral direction being provided by an actual tapering of the waveguide and the taper in the vertical direction (i e perpendicular to the plane of the chip) being provided by means of the laterally tapered upper portion 5
  • the problems associated with forming a vertically tapered waveguide, i e defined by non-vertical surfaces, as used in some of the prior art are thus avoided
  • the shape and dimensions of the tapered rib waveguide are such that if the large multi-mode waveguide is excited in a fundamental mode only, this mode is forced down into the smaller single-mode waveguide as the cross-sectional shape of the waveguide changes gradually from that of the larger waveguide to that of the smaller waveguide
  • the effective refractive index in the upper portion 5 is progressively reduced as it tapers This forces the mode into the lower portion 4 of the waveguide
  • the tapered rib waveguide does not require a refractive index difference between the two portions or for the maintenance of single-mode operation of the larger waveguide
  • the larger 10 micron x 10 micron waveguide is a multi-mode waveguide but if it is excited by a fundamental mode on its axis, e g from an optical fibre the power in higher order modes is negligible
  • the large refractive index difference between the silicon waveguide and the silicon dioxide cladding helps ensure that the effective refractive index of the upper portion 5 is suppressed sufficiently for the optical mode to be substantially entirely guided into the lower portion 4 before the narrowest section thereof is reached
  • the upper portion 5 need not taper to a point so the difficulties of fabricating very narrow sections at the narrow end of the upper portion 5 can be avoided
  • the dimensions of the two portions 4 and 5 are selected in accordance with conventional requirements of rib waveguides and with appropriate dimensions substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller, single-mode waveguide
  • a typical example having dimensions as shown in the drawing provides a low- loss coupling (typically 0 1 dB or less) between the two waveguides
  • the tapered rib waveguide described herein may be used to provide a transition between a variety of sizes of waveguide and particularly from an optical fibre to a smaller integrated waveguide
  • the larger waveguide typically has cross-sectional dimensions in the range 7 - 12 microns wide by 7 - 12 microns deep (and is thus compatible with conventional optical fibres) and the smaller waveguide typically has cross-sectional dimensions in the range 2 - 5 microns wide by 4 - 5 microns deep (and is thus compatible with conventional integrated optical waveguides)
  • the depth is measured from the oxide layer 2
  • the input facet 6 may be formed by dry etching, no saw cuts or polishing being necessary
  • the facet 6 may be perpendicular to the axis of the waveguide or may be angled
  • tapered rib waveguide can be used in either direction, i e from a large waveguide to a small waveguide or from a small waveguide to a large waveguide
  • the tapered rib waveguide described above is easily integrated with other components of an integrated optical circuit
  • An optical fibre (not shown) inputting light into facet 6 may be positioned in a V-groove (not shown) provided in the silicon-on-insulator chip
  • the position of the V-groove and of the tapered rib waveguide may oe defined by a common lithograpnic step so they are automatically aligned with each other
  • the tapered rib waveguide structure described herein may be formed on such an overhang to provide a transition between a large multi-mode waveguide for receiving light from the optical fibre and a smaller single-mode integrated waveguide formed on the chip
  • the illustrated embodiment comprises a tapered rib waveguide formed as a straight waveguide In some circumstances, however, it may be desirable to form a similar structure on a gradually curving waveguide
  • the tapered sides of the upper and lower portions 4 and 5 do not need to be straight but may also be curved, nor need they necessarily be symmetrical
  • the taper should be gradual If the taper is too rapid the losses will be higher On the other hand if the taper is too gradual the device may be larger than is desirable A compromise between these two requirements is usually necessary
  • a tapered section of the silicon slab 7 may also be removed as shown by dashed lines in Figure 1 Removal of the slab 7 adjacent the nb waveguide increases the refractive index difference between the waveguide and its surroundings and by gradually narrowing the gap 7, the effective refractive index difference is gradually reduced
  • the illustrated embodiment shows a tapered waveguide having two layers, i e the upper portion 5 and lower portion 4
  • further layers may be provided, e g an additional tapering portion on top of the upper portion 5, and that the tapering may occur in two or more stages at different positions along the waveguide
  • FIGS 2A and 2B are schematic diagrams illustrating an example of a multistage tapered rib waveguide
  • a 10 microns high rib 10 initially tapers to a 7 microns high rib 11 which then tapers to a 4 microns high nb 12
  • Figure 2B shows a cross-section taken across line a-a of Figure 2A
  • a 10 x 10 microns waveguide can be tapered down in two stages to a 2 x 4 microns waveguide, e g for coupling with a laser
  • the tapered portion 10 overlaps the tapered portion 11 so as to reduce or minimise losses due to light diverging as it is forced down from portion 10 to portion 11 and, similarly, tapered portion 11 overlaps tapered portion 12
  • Figures 3 - 5 show further embodiments of a tapered waveguide
  • the arrangement shown in Figures 3A and 3B is similar to that shown in Figure 1 except that the tapered structure 13, comprising the upper and lower portions 5 and 4 and a substrate 14 on which these are formed, is a separate component which is mounted on a silicon-on-insulator chip 15 and aligned with a waveguide 16 thereon
  • the tapered structure 13 is formed of a different material e g silicon dioxide or silicon nitride, and enables it to be fabricated separately from the remainder of the optical circuit
  • the tapered structure 13 is mounted on the silicon-on-insulator chip 15 by locating surfaces 13A and 13B against corresponding surfaces 15A and 15B in a recess or cut-out section of the chip 15 A further pair of abutting surfaces (not shown) may be provided for locating it in a lateral direction relative to the waveguide 16
  • the tapered structure 13 may be secured in place by means of adhesive
  • a two-stage tapered waveguide may also be made in a similar manner as shown in Figures 4A and 4B
  • a separate tapered structure 17 is provided which comprises the upper tapered portion 5 on an untapered portion 18 and a substrate 19
  • the lower tapered portion 4 is formed on the silicon-on- insulator chip 15
  • the tapered structure 17 is mounted on and aligned with the silicon-on-insulator chip 15 in a similar manner to that described above
  • Figures 5A and 5B show a further arrangement in which a tapered structure 20 of a different material is fabricated directly onto a silicon-on-insulator chip 15
  • Figures 5A and 5B are similar to Figures 3A and 3B but in this case the upper and lower portions 5 and 4 and substrate 14 are fabricated directly onto the chip 15
  • the tapered structure 20 may, for example, be formed of silicon dioxide deposited or grown on the silicon-on-insulator chip 15 or formed of a polymer material spun onto the chip
  • an anti- reflective coating is preferably provided between the two to help reduce back- reflection of light oassmg from the tapered structure into the silicon-on-insulator device

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Integrated Circuits (AREA)
  • Optical Couplings Of Light Guides (AREA)

Abstract

A tapered rib waveguide tapering from a large, multi-mode optical waveguide to a smaller, single-mode optical waveguide, the tapered rib waveguide comprising two portions (4, 5) formed of the same material: a lower portion (4) which tapers laterally from the large waveguide to the smaller waveguide and an upper portion (5) formed on the lower portion (4), which tapers to a point (or other form of termination), the dimensions of the two portions (4, 5) being such that substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller, single-mode waveguide.

Description

A TAPERED RIB WAVEGUIDE
TECHNICAL FIELD
This invention relates to a tapered rib waveguide providing a transition from an optical waveguide of relatively large cross-section to an optical waveguide of smaller cross-section
BACKGROUND ART
An integrated optical circuit employs optical waveguides to transmit light around the circuit and to connect to external optical waveguides such as optical fibres The integrated optical waveguides and/or optical fibres may be of different cross-sectional size so there is a need for means to provide a transition from a waveguide of relatively large cross-section to a waveguide of smaller cross-section A variety of devices have been proposed for this purpose but they tend to be relatively complex and/or difficult to fabricate
This invention aims to provide a tapered rib waveguide which is of relatively simple construction is relatively easy to fabricate and which provides a low- loss transition from a large cross-section to a smaller cross-section
It should be noted that terms such as 'upper' 'lower", "laterally" etc used herein are used in a relative sense i e relative to the orientation of the apparatus shown in the accompanying drawing, and are not intended to imply any orientation with respect to the force of gravity
DISCLOSURE OF INVENTION
According to a first aspect of the present invention, there is provided a tapered rib waveguide tapering from a large multi-mode optical waveguide to a smaller, single-mode optical waveguide, the tapered rib waveguide comprising at least two portions formed of the same material a lower portion which tapers laterally from the large waveguide to the smaller waveguide and an upper portion, formed on the lower portion, which tapers to a point or other form of termination the dimensions of the two portions being arranged such that substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller single-mode waveguide
Preferred features of the invention will be apparent from the subsidiary claims of the specification and from the following description
BRIEF DESCRIPTION OF DRAWINGS
The invention will now be further described merely by way of example with reference to the accompanying drawings in which
Figure 1 shows a perspective view of a preferred embodiment of a tapered rib waveguide according to the invention
Figure 2A is a schematic plan view of another embodiment of a tapered rib waveguide according to the invention and Figure 2B a cross-section thereof, and
Figures 3A and 3B 4A and 4B, and 5A and 5B show schematic plan and side views of three further embodiments of a tapered rib waveguide according to the invention
BEST MODE OF CARRYING OUT THE INVENTION
The drawing shows a tapered rib waveguide tapering from a large multi-mode waveguide about 10 microns x 10 microns to a smaller single-mode waveguide about 4 3 microns x 4 microns
The illustrated waveguides are in the form of ribs formed on the upper surface of a silicon layer, e g of a silicon-on-insulator chip The silicon-on-insulator chip is preferably manufactured from conventional wafers such as those used in Very Large Scale Integration (VSLI) electronic circuits The paper "Reduced defect density in silicon-on-insulator structures formed by oxygen implantation in two steps" by J Morgail et al Appl Phys Lett, 54,p526,1989 describes the manufacture of suitable wafers Methods of manufacturing rib waveguides on a silicon-on-insulator chip are described in the paper "Low loss single mode optical waveguides with large cross-section in silicon-on-insulator" by J Schmidtchen et al, Electronic Letters, 27,p1486,1991
The drawing shows the rib waveguides formed in the silicon layer 1 of such a chip and shows the oxide layer 2 separating the silicon layer 1 from a silicon substrate 3 A silicon dioxide cladding (not shown) is also usually provided
The tapered rib waveguide shown in the drawing comprises two portions a lower portion 4 which tapers laterally from a width of about 10 microns to a width of about 4 microns over a length of about 1000 microns, and an upper portion 5, formed on the lower portion 4, which tapers from a width of about 10 microns to a point over a length of about 800 microns The upper portion 5 thus tapers more rapidly than the lower portion 4 and in the embodiment shown has a triangular wedge-like shape when viewed from above Both portions are, however, designed to provide a substantially adiabatic taper
In another arrangement (not shown), both the upper and lower portions 5 and 4 taper at the same angle so the sides of the two portions are parallel to each other In this case, the wide end of the upper portion 5 is narrower than the wide end of the lower portion 4
The upper and lower portions 5 and 4 preferably taper at an angle (with respect to the axis of the waveguide) of less than 1 degree and preferably less than 0 5 of a degree Such a gradual taper ensures that any losses caused by the taper are kept small The upper portion 4 tapers to a point or to some other form of termination In the arrangement shown in Figure 1 , the tapering section of the upper portion 5 is formed on top of the tapering section of the lower portion 4
The two portions 4 and 5 including the input facet 6, can be formed together by conventional lithography and dry etching as they are defined by vertical surfaces They are formed of the same material and thus have the same refractive index The two portions may be formed homogenously on the chip Alternatively, the upper portion 5 may be formed separately and mounted on the lower portion 4
The upper faces of the upper and lower portions 4 and 5 are substantially parallel to the plane of the chip i e the upper and lower portions 4 and 5 each have a substantially constant height above the surface of the chip (7 2 and 1 5 microns respectively, in the illustrated example)
The tapered rib waveguide shown in the drawing thus provides a two- dimensional taper, the taper in the lateral direction being provided by an actual tapering of the waveguide and the taper in the vertical direction (i e perpendicular to the plane of the chip) being provided by means of the laterally tapered upper portion 5 The problems associated with forming a vertically tapered waveguide, i e defined by non-vertical surfaces, as used in some of the prior art are thus avoided
The shape and dimensions of the tapered rib waveguide are such that if the large multi-mode waveguide is excited in a fundamental mode only, this mode is forced down into the smaller single-mode waveguide as the cross-sectional shape of the waveguide changes gradually from that of the larger waveguide to that of the smaller waveguide The effective refractive index in the upper portion 5 is progressively reduced as it tapers This forces the mode into the lower portion 4 of the waveguide It should be noted that the tapered rib waveguide does not require a refractive index difference between the two portions or for the maintenance of single-mode operation of the larger waveguide As indicated above, the larger 10 micron x 10 micron waveguide is a multi-mode waveguide but if it is excited by a fundamental mode on its axis, e g from an optical fibre the power in higher order modes is negligible
The large refractive index difference between the silicon waveguide and the silicon dioxide cladding (not shown) helps ensure that the effective refractive index of the upper portion 5 is suppressed sufficiently for the optical mode to be substantially entirely guided into the lower portion 4 before the narrowest section thereof is reached Thus as indicated above, the upper portion 5 need not taper to a point so the difficulties of fabricating very narrow sections at the narrow end of the upper portion 5 can be avoided
The dimensions of the two portions 4 and 5 are selected in accordance with conventional requirements of rib waveguides and with appropriate dimensions substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller, single-mode waveguide
A typical example having dimensions as shown in the drawing provides a low- loss coupling (typically 0 1 dB or less) between the two waveguides
The tapered rib waveguide described herein may be used to provide a transition between a variety of sizes of waveguide and particularly from an optical fibre to a smaller integrated waveguide The larger waveguide typically has cross-sectional dimensions in the range 7 - 12 microns wide by 7 - 12 microns deep (and is thus compatible with conventional optical fibres) and the smaller waveguide typically has cross-sectional dimensions in the range 2 - 5 microns wide by 4 - 5 microns deep (and is thus compatible with conventional integrated optical waveguides) As shown in Figure 1 , the depth is measured from the oxide layer 2 As indicated above the input facet 6 may be formed by dry etching, no saw cuts or polishing being necessary The facet 6 may be perpendicular to the axis of the waveguide or may be angled
It will also be appreciated that the tapered rib waveguide can be used in either direction, i e from a large waveguide to a small waveguide or from a small waveguide to a large waveguide
The tapered rib waveguide described above is easily integrated with other components of an integrated optical circuit An optical fibre (not shown) inputting light into facet 6 may be positioned in a V-groove (not shown) provided in the silicon-on-insulator chip The position of the V-groove and of the tapered rib waveguide may oe defined by a common lithograpnic step so they are automatically aligned with each other
The applicants co-pending application no PCT/GB96/01068 (Publication no W097/45234) describes a connection between an integrated optical waveguide and an optical fibre and is hereby incorporated herein This earlier application describes a rib waveguide formed on a silicon-on-insulator chip the rib waveguide and underlying layer of silicon dioxide overhanging the end of a V-groove formed in the chip in which an optical fibre is positioned so the end of the rib waveguide lies in close proximity with the end of the optical fibre the overhang being required as the end of the V-groove is not formed perpendicular to the surface of the chip
The tapered rib waveguide structure described herein may be formed on such an overhang to provide a transition between a large multi-mode waveguide for receiving light from the optical fibre and a smaller single-mode integrated waveguide formed on the chip The illustrated embodiment comprises a tapered rib waveguide formed as a straight waveguide In some circumstances, however, it may be desirable to form a similar structure on a gradually curving waveguide The tapered sides of the upper and lower portions 4 and 5 do not need to be straight but may also be curved, nor need they necessarily be symmetrical
As indicated above, the taper should be gradual If the taper is too rapid the losses will be higher On the other hand if the taper is too gradual the device may be larger than is desirable A compromise between these two requirements is usually necessary
In addition to tapering the lower portion 4 a tapered section of the silicon slab 7 may also be removed as shown by dashed lines in Figure 1 Removal of the slab 7 adjacent the nb waveguide increases the refractive index difference between the waveguide and its surroundings and by gradually narrowing the gap 7, the effective refractive index difference is gradually reduced
The illustrated embodiment shows a tapered waveguide having two layers, i e the upper portion 5 and lower portion 4 However, it will be appreciated that further layers may be provided, e g an additional tapering portion on top of the upper portion 5, and that the tapering may occur in two or more stages at different positions along the waveguide
Figures 2A and 2B are schematic diagrams illustrating an example of a multistage tapered rib waveguide A 10 microns high rib 10 initially tapers to a 7 microns high rib 11 which then tapers to a 4 microns high nb 12 Figure 2B shows a cross-section taken across line a-a of Figure 2A By this means a 10 x 10 microns waveguide can be tapered down in two stages to a 2 x 4 microns waveguide, e g for coupling with a laser The tapered portion 10 overlaps the tapered portion 11 so as to reduce or minimise losses due to light diverging as it is forced down from portion 10 to portion 11 and, similarly, tapered portion 11 overlaps tapered portion 12
Figures 3 - 5 show further embodiments of a tapered waveguide,
The arrangement shown in Figures 3A and 3B is similar to that shown in Figure 1 except that the tapered structure 13, comprising the upper and lower portions 5 and 4 and a substrate 14 on which these are formed, is a separate component which is mounted on a silicon-on-insulator chip 15 and aligned with a waveguide 16 thereon This enables the tapered structure 13 to be formed of a different material e g silicon dioxide or silicon nitride, and enables it to be fabricated separately from the remainder of the optical circuit
The tapered structure 13 is mounted on the silicon-on-insulator chip 15 by locating surfaces 13A and 13B against corresponding surfaces 15A and 15B in a recess or cut-out section of the chip 15 A further pair of abutting surfaces (not shown) may be provided for locating it in a lateral direction relative to the waveguide 16 The tapered structure 13 may be secured in place by means of adhesive
A two-stage tapered waveguide may also be made in a similar manner as shown in Figures 4A and 4B In this case, a separate tapered structure 17 is provided which comprises the upper tapered portion 5 on an untapered portion 18 and a substrate 19 The lower tapered portion 4 is formed on the silicon-on- insulator chip 15 The tapered structure 17 is mounted on and aligned with the silicon-on-insulator chip 15 in a similar manner to that described above
Figures 5A and 5B show a further arrangement in which a tapered structure 20 of a different material is fabricated directly onto a silicon-on-insulator chip 15 Figures 5A and 5B are similar to Figures 3A and 3B but in this case the upper and lower portions 5 and 4 and substrate 14 are fabricated directly onto the chip 15 The tapered structure 20 may, for example, be formed of silicon dioxide deposited or grown on the silicon-on-insulator chip 15 or formed of a polymer material spun onto the chip
As the tapered structures 13, 17 and 20 are formed of a different material compared to the waveguide 16 (and lower portion 4 in Figure 4), an anti- reflective coating is preferably provided between the two to help reduce back- reflection of light oassmg from the tapered structure into the silicon-on-insulator device
Although the examples described above are formed on a siiicon-on-insulator chip and although this has the advantages referred to above, a similar tapered rib waveguide can be formed on other types of chip

Claims

A tapered rib waveguide tapering from a large multi-mode optical waveguide to a smaller, single-mode optical waveguide the tapered rib waveguide comprising at least two portions formed of the same material a lower portion which tapers laterally from the large waveguide to the smaller waveguide and an upper portion, formed on the lower portion, which tapers to a point or other form of termination the dimensions of the two portions being arranged such that substantially all of a fundamental mode propagated in the large multi-mode waveguide is coupled to the smaller, single-mode waveguide
A tapered nb waveguide as claimed in Claim 1 in which the shapes of the upper and lower portion are defined by vertical surfaces
A tapered rib waveguide as claimed in Claim 1 or 2 in which a tapering section of the upper portion overlaps or is formed on top of a tapering section of the lower portion
A tapered rib waveguide as claimed in Claim 1 , 2 or 3 in which the upper and lower portions are each of substantially constant height
A tapered nb waveguide as claimed in any preceding claim in which the upper and lower portion tapers laterally at an angle (with respect to the axis of the waveguide) of less than 1 degree and preferably less than 0 5 of a degree
A tapered rib waveguide as claimed in any preceding claim in which the large waveguide has cross-sectional dimensions in the range 7 - 12 microns wide by 7 - 12 microns deep
A tapered nb waveguide as claimed in any preceding claim in which the smaller waveguide has cross-sectional dimensions in the range 2 - 5 microns wide by 4 - 5 microns deep
A tapered rib waveguide as claimed in any preceding claim in which the first and second portions are formed homogenously
A tapered nb waveguide as claimed in any preceding claim having a further tapered portion whereby tapering occurs in stages from a large waveguide, to an intermediate size waveguide and then to a small waveguide
A tapered rib waveguide as claimed in any preceding claim in which a tapered portion of a slab waveguide adjacent the rib waveguide is also removed
A tapered rib waveguide as claimed in any preceding claim formed on a sihcon-oπ-iπsulator chip
A tapered nb waveguide as claimed in Claim 11 aligned with a V-groove for receiving an optical fibre
A tapered rib waveguide as claimed in Claim 1 1 and 12 formed on a part of the silicon chip which overhangs an end of the V-groove formed in the
A tapered nb waveguide as claimed in any preceding claim in which the upper portion is formed as part of a separate structure which is mounted in alignment with the smaller, single-mode waveguide
15. A tapered rib waveguide as claimed in Claim 14 in which the lower portion and the upper portion are formed as part of a separate structure which is mounted in alignment with the smaller, single-mode waveguide.
16. A tapered rib waveguide as claimed in any preceding claim in which the upper and/or the lower portion are formed of a different material than the smaller, singie-mode waveguide.
17. A tapered rib waveguide as claimed in Claim 16 in which the upper and lower portions are formed of a material which is grown, deposited or spun onto a substrate on which the smaller, single-mode waveguide is formed.
18. A tapered rib waveguide as claimed in any preceding ciaim providing a coupling between an optical fibre aπα an integrated optical waveguide.
19 . A tapered rib waveguide substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawings.
PCT/GB1998/000384 1997-02-07 1998-02-06 A tapered rib waveguide WO1998035250A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
DE69802948T DE69802948T2 (en) 1997-02-07 1998-02-06 A TAPERED ROD WAVE LADDER
AU59982/98A AU5998298A (en) 1997-02-07 1998-02-06 A tapered rib waveguide
JP53400798A JP2001510589A (en) 1997-02-07 1998-02-06 Tapered ribbed waveguide
EP98903157A EP1015922B1 (en) 1997-02-07 1998-02-06 A tapered rib waveguide
CA002274176A CA2274176A1 (en) 1997-02-07 1998-02-06 A tapered rib waveguide

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9702579.5 1997-02-07
GB9702579A GB2317023B (en) 1997-02-07 1997-02-07 A tapered rib waveguide

Publications (1)

Publication Number Publication Date
WO1998035250A1 true WO1998035250A1 (en) 1998-08-13

Family

ID=10807282

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1998/000384 WO1998035250A1 (en) 1997-02-07 1998-02-06 A tapered rib waveguide

Country Status (9)

Country Link
US (1) US6108478A (en)
EP (1) EP1015922B1 (en)
JP (1) JP2001510589A (en)
CN (1) CN1146736C (en)
AU (1) AU5998298A (en)
CA (1) CA2274176A1 (en)
DE (1) DE69802948T2 (en)
GB (1) GB2317023B (en)
WO (1) WO1998035250A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2355312A (en) * 1999-10-13 2001-04-18 Bookham Technology Ltd Integrated optical components on a silicon-on-insulator chip
WO2002042808A2 (en) * 2000-11-24 2002-05-30 Applied Wdm, Inc. Optical waveguide multimode to single mode transformer
US6556759B2 (en) 2001-03-16 2003-04-29 Bookham Technology Plc Integrated optical device
EP1356327A2 (en) * 2000-12-14 2003-10-29 Shipley Company LLC Optical waveguide termination with vertical and horizontal mode shaping
US7221843B2 (en) 2002-04-11 2007-05-22 Valtion Teknillinen Tutkimuskeskus Optical waveguide

Families Citing this family (106)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ID20168A (en) * 1996-11-07 1998-10-15 Philips Electronics Nv DATA PROCESSING AT A BIT FLOW SIGNAL
GB2321130B (en) 1997-12-23 1998-12-23 Bookham Technology Ltd An integrated optical transceiver
GB2334789B (en) * 1998-06-12 2000-01-19 Bookham Technology Ltd A waveguide end face
KR100277695B1 (en) * 1998-09-12 2001-02-01 정선종 Method for manufacturing a substrate for hybrid optical integrated circuit using S-O optical waveguide
KR100333900B1 (en) * 1999-01-21 2002-04-24 윤종용 Mode shape converter, its manufacturing method and integrated optical device comprising it
US6826220B2 (en) * 1999-12-27 2004-11-30 Corning O.T.I. S.R.L. Semiconductor laser element having a diverging region
US6625182B1 (en) * 2000-04-20 2003-09-23 Corning Incorporated Semiconductor or solid-state laser having an external fiber cavity
US6525864B1 (en) 2000-07-20 2003-02-25 Nayna Networks, Inc. Integrated mirror array and circuit device
GB2367376B (en) * 2000-09-13 2003-04-30 Bookham Technology Plc Rib waveguide device with mode filter
US7068870B2 (en) * 2000-10-26 2006-06-27 Shipley Company, L.L.C. Variable width waveguide for mode-matching and method for making
GB2369453B (en) * 2000-11-24 2002-07-31 Bookham Technology Plc Fabrication of integrated circuit
US6563997B1 (en) 2000-11-28 2003-05-13 Lighteross, Inc. Formation of a surface on an optical component
US7113704B1 (en) 2000-11-28 2006-09-26 Kotura, Inc. Tunable add/drop node for optical network
US6596185B2 (en) 2000-11-28 2003-07-22 Lightcross, Inc. Formation of optical components on a substrate
WO2003050580A1 (en) * 2001-12-05 2003-06-19 Shipley Company, L.L.C. Optical waveguide termination with vertical and horizontal mode shaping
US7251406B2 (en) * 2000-12-14 2007-07-31 Shipley Company, L.L.C. Optical waveguide termination with vertical and horizontal mode shaping
US6600864B2 (en) * 2000-12-20 2003-07-29 Intel Corporation Method and apparatus for switching an optical beam using an optical rib waveguide
US7158701B2 (en) * 2001-02-21 2007-01-02 Shipley Company, L.L.C. Method for making optical devices with a moving mask and optical devices made thereby
GB2374155A (en) * 2001-03-16 2002-10-09 Bookham Technology Plc A tapered optical waveguide formed with two substrates
GB2373342A (en) * 2001-03-16 2002-09-18 Bookham Technology Plc Optical waveguide structure with etch stop layer
US6792180B1 (en) 2001-03-20 2004-09-14 Kotura, Inc. Optical component having flat top output
DE60200132T2 (en) * 2001-03-29 2004-08-26 Interuniversitair Microelektronica Centrum Vzw Tapered waveguide (taper) with lateral beam-limiting rib waveguides
US6912345B2 (en) * 2001-03-30 2005-06-28 Shipley Company, L.L.C. Tapered optical fiber for coupling to diffused optical waveguides
AU2002364688A1 (en) * 2001-04-03 2003-06-10 Little Optics, Inc. Optical waveguide mode transformer
US20020158047A1 (en) * 2001-04-27 2002-10-31 Yiqiong Wang Formation of an optical component having smooth sidewalls
US6853773B2 (en) * 2001-04-30 2005-02-08 Kotusa, Inc. Tunable filter
US6614965B2 (en) 2001-05-11 2003-09-02 Lightcross, Inc. Efficient coupling of optical fiber to optical component
US6891685B2 (en) * 2001-05-17 2005-05-10 Sioptical, Inc. Anisotropic etching of optical components
US6748125B2 (en) 2001-05-17 2004-06-08 Sioptical, Inc. Electronic semiconductor control of light in optical waveguide
US6912330B2 (en) * 2001-05-17 2005-06-28 Sioptical Inc. Integrated optical/electronic circuits and associated methods of simultaneous generation thereof
US20020181869A1 (en) * 2001-06-01 2002-12-05 Wenhua Lin Tunable dispersion compensator
US6674929B2 (en) 2001-06-01 2004-01-06 Lightcross, Inc. Tunable optical filter
US20040114869A1 (en) * 2001-06-15 2004-06-17 Fike Eugene E. Mode converter including tapered waveguide for optically coupling photonic devices
US20020191916A1 (en) * 2001-06-15 2002-12-19 Confluent Photonics, Corporation Vertical waveguide tapers for optical coupling between optical fibers and thin silicon waveguides
US6771851B1 (en) 2001-06-19 2004-08-03 Nayna Networks Fast switching method for a micro-mirror device for optical switching applications
US20030012537A1 (en) * 2001-07-11 2003-01-16 Chi Wu Method of forming an optical component
US6614951B2 (en) 2001-08-06 2003-09-02 Lightcross, Inc. Optical component having a flat top output
CN102621630B (en) 2001-10-30 2015-03-25 Hoya美国公司 Optical junction apparatus and methods employing optical power transverse-transfer
US6853797B2 (en) * 2001-11-05 2005-02-08 Kotura, Inc. Compact optical equalizer
SE521419C2 (en) * 2001-11-09 2003-10-28 Ericsson Telefon Ab L M MMI-based device
US20030091291A1 (en) * 2001-11-15 2003-05-15 Sam Keo Smoothing facets on an optical component
US6714704B2 (en) 2001-11-29 2004-03-30 Lightcross, Inc. Optical component having selected bandwidth
US20040020896A1 (en) * 2002-02-15 2004-02-05 Lockheed Martin Corporation Tapered optical fiber for fiber to waveguide interconnection
GB2388917A (en) * 2002-05-25 2003-11-26 Bookham Technology Plc Semiconductor optical waveguide with a varying taper
US6810168B1 (en) 2002-05-30 2004-10-26 Kotura, Inc. Tunable add/drop node
US6956983B2 (en) 2002-05-31 2005-10-18 Intel Corporation Epitaxial growth for waveguide tapering
US6885795B1 (en) 2002-05-31 2005-04-26 Kotusa, Inc. Waveguide tap monitor
US6989284B2 (en) * 2002-05-31 2006-01-24 Intel Corporation Fabrication of a waveguide taper through ion implantation
US6921490B1 (en) 2002-09-06 2005-07-26 Kotura, Inc. Optical component having waveguides extending from a common region
US7079727B1 (en) 2002-10-09 2006-07-18 Little Optics, Inc. Integrated optical mode shape transformer and method of fabrication
US20040202429A1 (en) * 2003-04-10 2004-10-14 Lambda Crossing Ltd. Planar optical component for coupling light to a high index waveguide, and method of its manufacture
WO2004111694A1 (en) * 2003-06-13 2004-12-23 Pirelli & C. S.P.A. Tapered mode transformer
US7359593B2 (en) * 2003-10-09 2008-04-15 Infinera Corporation Integrated optical mode shape transformer and method of fabrication
EP1706767B1 (en) 2003-12-29 2019-06-05 Google LLC Optical coupling device
US20050185893A1 (en) * 2004-02-20 2005-08-25 Ansheng Liu Method and apparatus for tapering an optical waveguide
CA2560845C (en) * 2004-03-24 2011-05-24 Sioptical, Inc. Optical crossover in thin silicon
WO2005111680A1 (en) * 2004-05-18 2005-11-24 Valtion Teknillinen Tutkimuskeskus A structure comprising an adiabatic coupler for adiabatic coupling of light between two optical waveguides and method for manufacturing such a structure
US7088890B2 (en) * 2004-11-30 2006-08-08 Intel Corporation Dual “cheese wedge” silicon taper waveguide
CN101320111B (en) * 2007-06-04 2011-04-13 李冰 Parallel mode converter and optical divider composed by the same
US7668420B2 (en) * 2007-07-26 2010-02-23 Hewlett-Packard Development Company, L.P. Optical waveguide ring resonator with an intracavity active element
US7665903B2 (en) * 2007-10-03 2010-02-23 Avago Technologies Fiber Ip (Singapore) Pte. Ltd. Optical receptacle having an electrically isolating ring for electrically isolating the signal ground and the chassis ground in an optical transceiver module
KR100937589B1 (en) * 2007-11-07 2010-01-20 한국전자통신연구원 Hybrid LASER Diode
US8066437B2 (en) * 2009-03-12 2011-11-29 Avago Technologies Fiber Ip (Singapore) Pte. Ltd Optical transceiver module providing EMI shielding and electrical isolation between a signal ground and a chassis ground
SG181770A1 (en) 2009-12-23 2012-07-30 Agency Science Tech & Res Optical converter and method of manufacturing the same
JP2011164376A (en) * 2010-02-10 2011-08-25 Mitsubishi Electric Corp Spot size conversion waveguide
US8488923B2 (en) * 2010-03-29 2013-07-16 Intel Corporation Multimode optical coupler interfaces
US8649245B2 (en) * 2010-03-29 2014-02-11 Seagate Technology Llc Direct waveguide light delivery to NFT for heat assisted magnetic recording
WO2011127840A1 (en) * 2010-04-15 2011-10-20 Shanghai Silight Technology Co., Ltd Method for fabricating waveguides using epitaxial growth
JP5685843B2 (en) * 2010-07-13 2015-03-18 日本電気株式会社 Optical waveguide manufacturing method and optical waveguide
WO2012042708A1 (en) 2010-09-28 2012-04-05 日本電気株式会社 Optical waveguide structure and optical waveguide device
US9977188B2 (en) * 2011-08-30 2018-05-22 Skorpios Technologies, Inc. Integrated photonics mode expander
US9885832B2 (en) 2014-05-27 2018-02-06 Skorpios Technologies, Inc. Waveguide mode expander using amorphous silicon
CN103998961A (en) * 2011-09-29 2014-08-20 英特尔公司 Vertical optical coupler for planar photonic circuits
US10288805B2 (en) * 2012-02-13 2019-05-14 Mellanox Technologies Silicon Photonics Inc. Coupling between optical devices
JP5933293B2 (en) 2012-03-01 2016-06-08 富士通株式会社 Optical device, optical transmitter, optical receiver, optical transmitter / receiver, and method of manufacturing optical device
US9217836B2 (en) 2012-10-23 2015-12-22 Kotura, Inc. Edge coupling of optical devices
US9274282B2 (en) * 2013-08-23 2016-03-01 Cisco Technology, Inc. Coupling light from an external source to a waveguide using a multi-step converter
JP2015084019A (en) * 2013-10-25 2015-04-30 富士通株式会社 Spot size converter and optical device
KR20150062231A (en) 2013-11-28 2015-06-08 한국전자통신연구원 A semiconductor laser and method of forming the same
GB2522252B (en) 2014-01-20 2016-04-20 Rockley Photonics Ltd Tunable SOI laser
GB2522410A (en) * 2014-01-20 2015-07-29 Rockley Photonics Ltd Tunable SOI laser
JP6369036B2 (en) * 2014-02-04 2018-08-08 日本電気株式会社 Optical waveguide and optical waveguide manufacturing method
CN106133999A (en) * 2014-02-06 2016-11-16 斯考皮欧技术有限公司 The integrated type multi-stage taper coupler coupled with optical fiber for waveguide
FR3018616A1 (en) * 2014-03-17 2015-09-18 St Microelectronics Crolles 2 BROADBAND MULTI-MODE INTERFERENCE DEVICE
KR20160147018A (en) * 2014-04-30 2016-12-21 후아웨이 테크놀러지 컴퍼니 리미티드 Inverse taper waveguides for low-loss mode converters
US20160306117A1 (en) * 2015-04-17 2016-10-20 Christopher Middlebrook Tapered polymer waveguide
US10317620B2 (en) 2015-07-01 2019-06-11 Rockley Photonics Limited Interposer beam expander chip
EP3206062B1 (en) * 2016-02-12 2023-01-04 Huawei Technologies Research & Development Belgium NV Waveguide structure for optical coupling
US11699892B2 (en) 2016-02-19 2023-07-11 Rockley Photonics Limited Discrete wavelength tunable laser
GB2547467A (en) 2016-02-19 2017-08-23 Rockley Photonics Ltd Tunable laser
US11037839B2 (en) 2016-07-13 2021-06-15 Rockley Photonics Limited Integrated structure and manufacturing method thereof
US10811848B2 (en) 2017-06-14 2020-10-20 Rockley Photonics Limited Broadband arbitrary wavelength multichannel laser source
US10718668B2 (en) 2017-08-08 2020-07-21 Massachusetts Institute Of Technology Miniaturized Fourier-transform Raman spectrometer systems and methods
US10649148B2 (en) 2017-10-25 2020-05-12 Skorpios Technologies, Inc. Multistage spot size converter in silicon photonics
WO2020006337A1 (en) 2018-06-28 2020-01-02 Massachusetts Institute Of Technology Systems and methods for raman spectroscopy
CN109445032A (en) * 2019-01-14 2019-03-08 科新网通科技有限公司 SiON waveguide and optical coupling structure and preparation method thereof
US11360263B2 (en) 2019-01-31 2022-06-14 Skorpios Technologies. Inc. Self-aligned spot size converter
WO2020167370A1 (en) 2019-02-11 2020-08-20 Massachusetts Institute Of Technology High-performance on-chip spectrometers and spectrum analyzers
WO2020201829A1 (en) * 2019-04-01 2020-10-08 Rockley Photonics Limited Photonic buried interposer
US11506496B2 (en) 2019-07-10 2022-11-22 Anello Photonics, Inc. System architecture for integrated photonics optical gyroscopes
US10731988B1 (en) * 2019-07-10 2020-08-04 Anello Photonics, Inc. System architecture for integrated photonics optical gyroscopes
US11588062B2 (en) * 2020-10-08 2023-02-21 Globalfoundries U.S. Inc. Photodetectors including a coupling region with multiple tapers
CN112285829A (en) * 2020-11-23 2021-01-29 亨通洛克利科技有限公司 Silicon-based light spot mode field converter and manufacturing process thereof
CN112612078B (en) * 2020-12-18 2023-02-10 海南师范大学 High-efficiency coupling waveguide based on GOI or SOI and preparation method thereof
CN113534337B (en) * 2021-07-15 2022-08-16 中南大学 Processing method and structure of silicon photonic chip optical coupling structure
IT202200022593A1 (en) * 2022-11-03 2024-05-03 Consorzio Naz Interuniversitario Per Le Telecomunicazioni OPTOCOUPLER AND METHOD OF MANUFACTURING IT

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5078516A (en) * 1990-11-06 1992-01-07 Bell Communications Research, Inc. Tapered rib waveguides
US5444805A (en) * 1992-03-07 1995-08-22 Robert Bosch Gmbh Integrated optical component
EP0687925A2 (en) * 1994-06-08 1995-12-20 Hoechst Aktiengesellschaft Method of forming an optical coupling waveguide and a lightguide device having the optical coupling waveguide

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2684823B1 (en) * 1991-12-04 1994-01-21 Alcatel Alsthom Cie Gle Electric SEMICONDUCTOR OPTICAL COMPONENT WITH EXTENDED OUTPUT MODE AND MANUFACTURING METHOD THEREOF.
CA2253511A1 (en) * 1996-05-03 1997-11-13 Bookham Technology Plc Connection between an integrated optical waveguide and an optical fibre

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5078516A (en) * 1990-11-06 1992-01-07 Bell Communications Research, Inc. Tapered rib waveguides
US5444805A (en) * 1992-03-07 1995-08-22 Robert Bosch Gmbh Integrated optical component
EP0687925A2 (en) * 1994-06-08 1995-12-20 Hoechst Aktiengesellschaft Method of forming an optical coupling waveguide and a lightguide device having the optical coupling waveguide

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TANG C K ET AL: "DEVELOPMENT OF A LIBRARY OF LOW-LOSS SILICON-ON-INSULATOR OPTOELECTRONIC DEVICES", IEE PROCEEDINGS: OPTOELECTRONICS, vol. 143, no. 5, October 1996 (1996-10-01), pages 312 - 315, XP000680746 *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2355312A (en) * 1999-10-13 2001-04-18 Bookham Technology Ltd Integrated optical components on a silicon-on-insulator chip
WO2001027670A1 (en) * 1999-10-13 2001-04-19 Bookham Technology Plc Method of fabricating an integrated optical component
GB2355312B (en) * 1999-10-13 2001-09-12 Bookham Technology Ltd Method of fabricating an integrated optical component
WO2002042808A2 (en) * 2000-11-24 2002-05-30 Applied Wdm, Inc. Optical waveguide multimode to single mode transformer
WO2002042808A3 (en) * 2000-11-24 2003-04-17 Applied Wdm Inc Optical waveguide multimode to single mode transformer
US6580850B1 (en) 2000-11-24 2003-06-17 Applied Wdm, Inc. Optical waveguide multimode to single mode transformer
EP1356327A2 (en) * 2000-12-14 2003-10-29 Shipley Company LLC Optical waveguide termination with vertical and horizontal mode shaping
EP1356327B1 (en) * 2000-12-14 2008-04-16 Shipley Company LLC Optical mode size converter with vertical and horizontal mode shaping
US6556759B2 (en) 2001-03-16 2003-04-29 Bookham Technology Plc Integrated optical device
US7221843B2 (en) 2002-04-11 2007-05-22 Valtion Teknillinen Tutkimuskeskus Optical waveguide

Also Published As

Publication number Publication date
US6108478A (en) 2000-08-22
EP1015922A1 (en) 2000-07-05
AU5998298A (en) 1998-08-26
CN1146736C (en) 2004-04-21
JP2001510589A (en) 2001-07-31
DE69802948D1 (en) 2002-01-24
GB2317023A (en) 1998-03-11
GB2317023B (en) 1998-07-29
CA2274176A1 (en) 1998-08-13
CN1246928A (en) 2000-03-08
GB9702579D0 (en) 1997-03-26
EP1015922B1 (en) 2001-12-12
DE69802948T2 (en) 2002-09-12

Similar Documents

Publication Publication Date Title
US6108478A (en) Tapered rib waveguide
US7088890B2 (en) Dual “cheese wedge” silicon taper waveguide
US6571039B1 (en) Optical waveguide having a weakly-confining waveguide section and a strongly-confining waveguide section optically coupled by a tapered neck
US5078516A (en) Tapered rib waveguides
EP1356327B1 (en) Optical mode size converter with vertical and horizontal mode shaping
US8000565B2 (en) Buried dual taper waveguide for passive alignment and photonic integration
US20080044126A1 (en) Integrated Optical Waveguide Structure with Low Coupling Losses to an External Optical Field
CN107111064B (en) Horizontally coupled to silicon waveguides
US20090245728A1 (en) Optical coupling device
CN111679363B (en) Silicon waveguide end face coupling structure and manufacturing method thereof
CA2425600A1 (en) Optical waveguides with trench structures
AU3721699A (en) Coupling optical fibre to waveguide
US10317620B2 (en) Interposer beam expander chip
CN114690310B (en) Edge coupler including fluted film
CN114384630B (en) Optical power splitter including nonlinear waveguide taper
US6556759B2 (en) Integrated optical device
US20020131744A1 (en) Optical waveguide structure
WO2021178727A1 (en) Evanescent coupler mode converters
CN116893472A (en) Edge coupler with nonlinear taper
CN116804784A (en) Edge coupler with continuously arranged tapers
CN115933051A (en) Edge coupler with confinement feature
WO2023215456A1 (en) Optically efficient silicon nitride edge couplers in photonic integrated circuits

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 98802408.X

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): AU CA CN IL JP KR SG

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref document number: 1998 534007

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2274176

Country of ref document: CA

Ref document number: 2274176

Country of ref document: CA

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1998903157

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1998903157

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1998903157

Country of ref document: EP