111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US008135250Bl
`
`(12) United States Patent
`Wach et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,135,250 Bl
`Mar. 13,2012
`
`(54) FACILE PRODUCTION OF OPTICAL
`COMMUNICATION ASSEMBLIES AND
`COMPONENTS
`
`(75)
`
`Inventors: Michael L. Wach, Alpharetta, GA (US);
`Dwight Holter, Naples, FL (US)
`
`(73) Assignee: Cirrex Systems LLC, Alpharetta, GA
`(US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.c. 154(b) by 613 days.
`
`(21) Appl. No.: 11/980,337
`
`(22) Filed:
`
`Oct. 30, 2007
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 10/429,166, filed on
`May 2, 2003, now Pat. No. 7,298,936, which is a
`continuation of application No. 10/010,854, filed on
`Dec. 4, 2001, now abandoned.
`
`(60) Provisional application No. 60/251,270, filed on Dec.
`4,2000.
`
`(51)
`
`Int. Cl.
`(2006.01)
`G02B 6/34
`(2006.01)
`C03B 37/018
`(2006.01)
`C03C 25/00
`(52) U.S. Cl. ............. 385/37; 359/566; 359/586; 65/392
`(58) Field of Classification Search .................... 385/37,
`3851147; 359/566,586, 900; 65/385,392
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`4,484,794 A
`1111984 Witte .............................. 385/46
`111987 Murphy .......................... 385/49
`4,639,074 A
`2/1992 Arii et al. ........................ 385/48
`5,091,986 A
`5/1993 Nagasawa et al. .............. 385/59
`5,214,730 A
`1111993 Cho et al. ........................ 385114
`5,265,177 A
`5,343,544 A
`8/1994 Boyd et al. ...................... 385/46
`5,351,324 A *
`9/1994 Forman ........................... 385/37
`5,633,975 A *
`5/1997 Gary et al.
`.................... 385/147
`5,838,853 A
`1111998 Jinnai et al. ..................... 385/50
`6,404,953 Bl *
`6/2002 Wach et al ...................... 385/31
`6,467,969 Bl
`10/2002 Shmulovich .................... 385/54
`6,542,673 Bl *
`4/2003 Holter et al ..................... 385/52
`6,728,444 B2 *
`4/2004 Brennan et al. ................. 385/37
`7,298,936 Bl *
`1112007 Wach et al ...................... 385114
`9/2002 Wach .............................. 385/24
`2002/0126953 Al
`2004/0052460 Al
`3/2004 Wach .............................. 385/39
`* cited by examiner
`Primary Examiner - Daniel Petkovsek
`
`(57)
`ABSTRACT
`A micro identification system supports facile optical assem(cid:173)
`blies and components. A segment of optical fiber can com(cid:173)
`prise an identifier formed via actinic radiation. The identifier
`can generate a laser interference pattern that can be read
`through a cylindrical surface of the optical fiber to determine
`a code. Modified optical fibers are those fibers that have been
`shaped or coated to an extent beyond the demands of normal
`communications optical fibers. In one example, modified
`fibers are no longer than about two feet in length. For another
`example, the modified fibers can have either a non-cylindrical
`end face, a non flat end face, an end face the plane of which is
`not perpendicular to the longitudinal axis of the waveguide,
`an end face coated with high density filter, or an identifier on
`or near an end face.
`
`1 Claim, 23 Drawing Sheets
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`1
`FACILE PRODUCTION OF OPTICAL
`COMMUNICATION ASSEMBLIES AND
`COMPONENTS
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`5
`
`2
`recall of information included in the identifYing mechanism.
`Content of U.S. Patent Application Ser. No. 60/213,983 has
`been inserted below under the heading "From U.S. Patent
`Application No. 60/213,983 Entitled "Micro Identifier Sys-
`tem and Components for Optical Assemblies"" with FIGS. 1,
`2, 2a, 3, 4, and 5 respectively renumbered as FIGS. 19,20,
`20a, 21, 22, and 23 and the letter "y" appended to the figure
`reference numbers to avoid confusion with other disclosed
`figures and figure reference numbers. Many of the individual
`components of such optical assemblies are extremely small
`and technically complex. Differences between component
`assembly pieces or even differences within individual pieces
`are difficult to discern. The' 983 patent application describes
`how etching or engraving, for example, of a cladding surface
`can provide precise and detailed product information, includ(cid:173)
`ing: the manufacturer, the core and cladding dimensions,
`compositions, indices of refraction, and other imprinting.
`Internal identifiers of that type can also be utilized for system
`integrityluniformity checks for quality assurance.
`Additional details may be important for other types of
`optical fibers. For example, the end face of one fiber may be
`intentionally angled so that its face is not uniformly perpen(cid:173)
`dicular to its axis and the axis of a waveguide with which it is
`to be mated. (See Cirrex U.S. patent application Ser. No.
`25 09/578,777, entitled, "Method and System for Increasing a
`Number of Information Channels Carried by Optical
`Waveguides," which is incorporated herein in its entirety by
`reference and which has now issued as U.S. Pat. No. 6,542,
`660.) For a very slight angle, it may be critical to have the end
`30 face precisely oriented as it mates with the waveguide. The
`extent to which the fiber core is off-center or elliptical may
`also be included in the identifier. The identifier on the fiber
`and the waveguide provides sufficient information for the
`mating to be precise.
`One advantage of using the peripheral surface of a fiber end
`face for the identifier is relative space availability. The entire
`periphery of the end face could be utilized if information
`space and image clarity are required. Similarly, the probabil(cid:173)
`ity of that area causing fiber function limitations is low and
`could be reduced further, for example, by covering disrupted
`(etched/engraved) surface areas with material that would
`restore transparency to wavelengths negatively affected with(cid:173)
`out detrimentally affecting the readability of the image. Such
`factors playa role in determining which identifier process,
`marking and location to utilize. It also may be critical to high
`volume production for the information to be read signifi-
`cantly in advance of the mating operation and in some cases
`even by a different manufacturer. Each improvement in one
`area exposes additional challenges for the manufacturing pro(cid:173)
`cesses in other areas, for example, in assuring appropriate,
`precise fiber to fiber, or fiber to waveguide mating.
`
`The present application is a continuation of and claims
`priority to U.S. Non-Provisional patent application Ser. No.
`10/429,166, entitled "Facile Production of Optical Commu- 10
`nication Assemblies and Components" and filed on May 2,
`2003 in the name ofWach et aI, now U.S. Pat. No. 7,298,936,
`which is a continuation of and claims priority to U.S. Non(cid:173)
`Provisional patent application Ser. No. 10/010,854, entitled
`"Facile Production of Optical Communication Assemblies 15
`and Components" and filed on Dec. 4, 2001 now abandoned
`in the name of Wach et a!., which claims priority under 35
`U.S.c. 119 to the filing date of Dec. 4, 2000 accorded to the
`U.S. Provisional Patent Application Ser. No. 60/251,270. The
`entire contents of U.S. Non-Provisional patent application 20
`Ser. No. 10/429,166 and U.S. Non-Provisional patent appli(cid:173)
`cation Ser. No.1 0101 0,854 are hereby incorporated herein by
`reference.
`
`BACKGROUND OF THE INVENTION
`
`Fiber to fiber and fiber to waveguide linking devices that
`have been described in the art tend to focus on a substantial
`length of fiber placed for linkage to another fiber or to a planar
`waveguide. Prior art connectors and splicing devices typi(cid:173)
`cally do not meet the increased demand for minimizing on(cid:173)
`line manufacturing time or part replacementlrepair time to
`meet the overall cost requirements for optical communica(cid:173)
`tions equipment, particularly in high volume production
`operations. With the tremendous need for increasing band- 35
`width, a need exists in the art for increased precision in such
`linkages and for modifYing or eliminating rate-limiting steps
`in component manufacturing. The increase in overall demand
`for high quality optical components at modest cost has inten(cid:173)
`sified the importance of achieving high quality consistently 40
`and efficiently.
`Fiber modification techniques disclosed in U.S. Pat. No.
`5,953,477, entitled "Method and Apparatus for Improved
`Fiber Optic Light Management," filed Mar. 13, 1997, address
`these challenges. However, the increased capability of sepa- 45
`rating wavelengths made possible by these advances has fur(cid:173)
`ther increased the need for precision in other aspects of manu(cid:173)
`facturing optical assemblies. Cirrex U.S. patent application
`Ser. No. 09/318,451, entitled, "Optical Assembly with High
`Performance Filter," filed May 25, 1999, (incorporated herein 50
`by reference in its entirety), which has now issued as U.S. Pat.
`No. 6,404,953, describes various modifications to fibers.
`Content of U.S. patent application Ser. No. 09/318,451 has
`been inserted below under the heading "From U.S. patent
`application Ser. No. 09/318,451 Entitled "Optical Assembly 55
`with High Performance Filter"" with FIGS. 1,2,3,4, 5, 67,
`8,9, 10, lla, and 11 b respectively renumbered as FIGS. 8, 9,
`10,11,12,13,14,15,16,17, 18a, and 18b and the letter "x"
`appended to the figure reference numbers to avoid confusion
`with other disclosed figures and figure reference numbers. 60
`Cirrex U.S. Patent Application Ser. No. 60/213,983 entitled,
`"Micro Identifier System and Components for Optical
`Assemblies," filed Jun. 24, 2000 (also incorporated herein by
`reference in its entirety) describes a system having an identi(cid:173)
`fying mechanism for high performance waveguides that is 65
`machine-readable (especially, by optical means, for example,
`using a laser interference pattern) for quick and accurate
`
`SUMMARY
`
`In accordance with the present invention, a modified fiber
`interlink, typically an optical assembly multi-channel sub(cid:173)
`component, can be created to form the optical link between
`multiple channel waveguides to be mated. For example,
`modified fiber interlinks form optical paths between multiple
`fibers and a multi-channel planar waveguide. Modified opti(cid:173)
`cal fibers are those that have been shaped or coated to an
`extent beyond the demands of normal communications opti(cid:173)
`cal fibers. In one example, modified fibers are no longer than
`about two feet in length and can have either a non-cylindrical
`end face, a non-flat end face, an end face the plane of which is
`not perpendicular to the longitudinal axis of the waveguide,
`an end face coated with high density filter, or an identifier on
`
`Page 25
`
`

`
`US 8,135,250 Bl
`
`3
`or near an end face. In another example, the modified fiber can
`include at least one high density filter in the interlink within
`an interlink channel.
`Modified fiber interlinks can be manufactured in a separate
`operation and thus taken off-line from the main optical 5
`assembly manufacturing line. These integral interlinks, in
`which fibers have been shaped so precisely and/or coated with
`special filters, can be included in optical assemblies to ulti(cid:173)
`mately provide their beneficial functions without slowing the
`entire assembly operation. This off-line production can result 10
`in a subcomponent that minimizes linkage time in the full
`component assembly operation. The subcomponent also can
`decrease the potential for defective linkages or less than opti(cid:173)
`mal perfonnance in both the subcomponent manufacturing
`operation and the assembly operation.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`4
`FIG. 14 is a perspective of two optical assemblies in mask
`end to mask end, mating connection, from U.S. patent appli(cid:173)
`cation Ser. No. 09/318,451.
`FIG. 15 is a cross sectional view illustrating two optical
`assemblies each having beveled end faces with mask end near
`mask end configuration illustrating mating orientation, with
`exaggerated fiber core, filter, and mask thickness dimensions,
`from U.S. patent application Ser. No. 09/318,451.
`FIG. 16 is a cross sectional view illustrating two optical
`assemblies oriented for end to end splice using a connection
`device mated to the masked assembly ends, from U.S. patent
`application Ser. No. 09/318,451.
`FIG. 17 is a cross sectional view illustrating two optical
`assemblies oriented for end to end splice using a connection
`15 device having a fluid entrylevacuation port, from U.S. patent
`application Ser. No. 09/318,451.
`FIG. 18 includes 18a, which is an end view of a splice
`connection device as in FIG. 17 and including a channel for
`aligning the fiber end faces, and 18b, which is a blow-up of the
`20 channel and its surrounds, from U.S. patent application Ser.
`No. 09/318,451.
`FIG. 19, from U.S. Patent Application No. 60/213,983,
`illustrates several embodiments of an identifier means.
`FIG. 20, from U.S. Patent Application No. 60/213,983,
`25 shows in perspective view a system that includes a reading
`means for sufficient identification to initiate appropriate reac-
`tion.
`FIG. 20a, from US Patent Application No. 60/213 983,
`illustrates in end view cutaway a drive having rollers support(cid:173)
`ing a fiber segment.
`FIG. 21, from U.S. Patent Application No. 60/213,983,
`illustrates in perspective view several options for placement
`or configuration of identifier spaces.
`FIG. 22, from U.S. Patent Application No. 60/213,983,
`illustrates a fiber having a core and a cladding.
`FIG. 23, from U.S. Patent Application No. 60/213,983,
`illustrates purposefully created index of refraction disrup(cid:173)
`tions in cladding of a fiber.
`
`FIG. 1 depicts in exaggerated perspective an interlink hav(cid:173)
`ing four differently configured waveguides in accordance
`with an exemplary embodiment of the present invention.
`FIG. 2 shows the exemplary interlink of FIG. 1 in cutaway
`along the AA plane.
`FIG. 3 depicts in exaggerated perspective a planar
`waveguide configured for mating with the exemplary inter(cid:173)
`link of FIG. 1.
`FIG. 3a illustrates in exaggerated perspective a planar
`waveguide face having a groove surrounding each port for
`mating with a mating projection surrounding each mating
`port on a modified fiber interlink in accordance with an exem- 30
`plary embodiment of the present invention.
`FIG. 3b illustrates a mating projection and a groove for a
`planar waveguide interlink interface in accordance with an
`exemplary embodiment of the present invention.
`FIG. 4 depicts in cutaway an interlink with cylindrical 35
`fibers with high density filters on fiber ends in accordance
`with an exemplary embodiment of the present invention.
`FIG. 5 illustrates a fiber of FIG. 4 having an identifier
`embedded thereon in accordance with an exemplary embodi-
`ment of the present invention.
`FIG. 6 illustrates in schematic two interlinks used in an
`add-drop multiplexer application in accordance with an
`exemplary embodiment of the present invention.
`FIG. 7 illustrates in cutaway additional configurations of
`waveguides in interlink applications in accordance with an 45
`exemplary embodiment of the present invention.
`FIG. 8 is a perspective of an optical assembly end portion
`illustrating a masked, filtered fiber end, from U.S. patent
`application Ser. No. 09/318,451.
`FIG. 9 is a cross sectional magnified view of an optical 50
`assembly in accordance with FIG. 8 with exaggerated fiber
`core, filter, and mask thickness dimensions, from U.S. patent
`application Ser. No. 09/318,451.
`FIG. 10 is an end view of an optical assembly illustrating a
`mask having a hexagonal exterior profile and a circular aper- 55
`ture, from U.S. patent application Ser. No. 09/318,451.
`FIG. 11 is a distorted perspective of an uncompleted optical
`assembly end portion illustrating a mask precursor having a
`hexagonal profile, from U.S. patent application Ser. No.
`09/318,451.
`FIG. 12 is an end view of a cluster of uncompleted optical
`assemblies end portions, from U.S. patent application Ser.
`No. 09/318,451.
`FIG. 13 is a perspective of two optical assemblies with
`masks placed in mask end near mask end configuration illus- 65
`trating mating orientation, from U.S. patent application Ser.
`No. 09/318,451.
`
`40
`
`DETAILED DESCRIPTION OF THE
`EXEMPLARY EMBODIMENTS
`
`As shown by the exemplary embodiment in FIG. 1, inter(cid:173)
`link 4 links by providing optical channels, waveguides 5, 6
`(an optical fiber formed by fusing fiber segment 6a to fiber
`segment 6b fonning junction 12a) 8, and 9, between a planar
`waveguide (see planar waveguide unit 30 in FIG. 3) and at
`least one optical fiber system 10 of which optical fiber 19/is
`a part. Optical fiber 19/ can be mated to waveguide 9, prefer(cid:173)
`ably an optical fiber, at interface 17, by inserting fiber 19/in
`channel or recess 4c of block 4a (See FIG. 2 for additional
`detail). For example, by using an appropriate epoxy, fiber 19/
`can be fused to fiber 9 with a filter disposed at the interface 17
`therebetween. Optical fiber 18/ can be mated to waveguide 8
`at interface 18 by inserting fiber 18/into a locking mechanism
`22 such as an optical seal housing. The locking mechanism 22
`is coupled to face 2 of the interlink 4 by flanges 21 that engage
`the locking mechanism 22. Disposed at interface 18 can be a
`filter. Overall, waveguides 5, 6, 8, and 9 of interlink 4 dem-
`60 onstrate various types of optical connections that can exist
`within interlink 4. It will be understood that the present inven(cid:173)
`tion is not limited to the number and types of waveguides
`shown within interlink 4. For example, FIG. 7 illustrates yet
`another exemplary embodiment of the type of waveguide,
`configuration that can be disposed within an interlink 4.
`Block 4a is rigid, constructed of material opaque to the
`wavelengths of light expected to be transmitted through the
`
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`US 8,135,250 Bl
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`5
`embedded waveguides and light to which the unit is exposed.
`The material is preferably a plastic that is resistant to thennal
`expansion and is thennally stable. Fibers IS/, 16/, 18Jofthe
`optical fiber system can mate with waveguide ends 15, 16, and
`18 respectively of interlink 4. Multi-channel planar optical 5
`waveguide unit 30 (see FIG. 3) has a docking surface 39 and
`ports 31, 32, 33' and 34 optically open to waveguide channels
`of planar optical waveguide unit 30 which ultimately com(cid:173)
`municate with waveguides 35a, 35b, 35c and 35d. Face sur(cid:173)
`face region 1 of interlink 4 (FIG. 1) and its positioning pins 10
`7a, 7b, 7c, 7d and 7e mate with docking surface 39 (FIG. 3)
`and its pin receptacles 37a, 37b, 37c, 37d, and 37e, respec(cid:173)
`tively. Ports 11, 12, 13 and 14 of interlink 4 (FIG. 1) mate
`precisely with ports 31, 32, 33 and 34 respectively (FIG. 3) of
`planar optical waveguide unit 30. Secure mating for each of 15
`the respective waveguide ends can be accomplished by using
`an appropriate epoxy or other material (e.g. index matching
`gel) to assure transparent connection. For less than pennanent
`connection, the mating could also be secured by using an
`index matching gel and a connection system that securely but 20
`releasably connects (e.g. using latches) interlink 4 face sur(cid:173)
`face 1 with the docking surface 39 of planar waveguide unit
`30. Another alternative that could be used in lieu of or with
`placement pins and receptacles is a male/female grooving
`system, as shown in exaggerated perspective in FIG. 3b.
`FIG. 3a shows a multi-channel planar waveguide face
`(docking surface) 36 having groove 36g spaced and com(cid:173)
`pletely but separately surrounding each of the ports, 31a, 32a,
`33a and 34a. A mating modified fiber interlink would include
`a precisely dimensioned face surface having shaped, continu- 30
`ous projections 26p that would mate with groove 36g, as
`illustrated in FIG. 3b. The interlink would also include ports
`that would mate precisely with ports 31a, 32a, 33a and 34a.
`As best shown in FIG. 3b, mating projection 26p mates
`exactly with groove 36g, but the projection could be modified 35
`to guide itself to the full depth of groove 36g. The advantage
`of a grooving system is that it helps to assure no unintended
`photon transfer between non mated ports.
`In FIG. 1, modified fiber interlink 4 includes optical
`waveguides of four different configurations for purposes of 40
`illustrating
`the versatility of applicant's
`invention.
`Waveguide 5 is a single mode optical fiber which between
`face 1 and face 2 of unit 4 is embedded in solid opaque block
`4a. A significant portion of optical fiber 5 protrudes from face
`2 for linking, desirably by fusion at end 15 to a matching 45
`optical fiber 151 of optical fiber system 10. The embedded
`part of optical fiber 5 has an axial cross section that has been
`modified to transition from a circular cross section at distal
`end 15 and extending beyond face 2 into block 4a to a rect(cid:173)
`angular cross section at the proximal end of fiber 5 at port 11. 50
`Each of the transitional optical waveguides 5, 6, 9 and 8 has a
`proximal end at least near face surface region 1. In an exem(cid:173)
`plary embodiment of this invention, waveguides 5,6,8,9 of
`interlink 4 are each a separate optical fiber, with at least one
`having on its proximal end an integral high density filter. In 55
`another exemplary embodiment, each separate fiber 5, 6, 8
`and 9 has a distal end and at least one has a high density filter
`on its distal end. Such filters are described in detail in U.S. Pat.
`No. 5,953,477 mentioned above. Optical fibers 5 and 6 of
`interlink 4 protrude from face surface region 2 and each has a 60
`distal end, 15 and 16, respectively, exterior to block 4a. The
`longitudinal axis of optical fiber 6 is positioned obliquely to
`face surface region 1. However, high density filter 12b on the
`proximal end of fiber 6 (shown more clearly in FIG. 2) is
`preferably parallel to an optical fiber face surface 1 because of 65
`the end shaping on both ends of fiber segment 6a and on the
`juncture end 12a of 6b. It is this sort of precision and flex-
`
`6
`ibility in fusing that highlights the advantages of the interlinks
`of the exemplary embodiments of the present invention. In
`another exemplary embodiment, the waveguides of interlink
`4 are optical fibers with the proximal end of the fibers 5 (at
`port 11), 6 (at port 12), 9 (at port 13) and 8 (at port 14) each
`being slightly recessed from face surface 1. This allows for an
`appropriate amount of epoxy or other optically transparent
`material for fusing the fiber ends, for example, to selected
`waveguide channels in planar waveguide unit 30.
`FIG. 4 illustrates a cross-sectional view of an interlink
`comprising cylindrical fibers with high density filters on fiber
`ends in accordance with an exemplary embodiment of the
`invention. Referring now to FIG. 4, an interlink 41 comprises
`a block 44 and cylindrical fibers 45/, 46/, 47/, and 48/ The
`block 44 is preferably constructed of a rigid material opaque
`to the wavelengths oflight expected to be transmitted through
`an embedded portion of the optical fibers 45/, 46/, 47/, and 48J
`and light to which the unit is exposed. The optical fibers 45/,
`46/, 47/, and 48Jprovide optical channels or waveguides for
`carrying optical signals. Along face surface 41 of the block
`44, the optical fibers 45/, 46/, 47/, and 48Jcomprise ports 45,
`46, 47, and 48, respectively. Filters 45b, 46b, 47b, and 48b,
`typically high density filters, are positioned along each proxi-
`25 mal end face of the optical fibers 45/, 46/, 47/, and 48/,
`respectively, at the ports 45, 46, 47, and 48 along the face 41.
`Distal ends 45a, 46a, 47a, and 48a of the optical fibers 45/,
`46/, 47/, and 48/, respectively, protrude from a face surface 42
`of the interlink 44. One or more of the distal ends 45a, 46a,
`47a, and 48a can include an optical filter, such as a high
`density filter 48a positioned at the distal end 48b. At the face
`surface 42, a significant portion of each optical fiber 45, 46,
`47, and 48 protrudes from the block 44 for linking, preferably
`by fusion to another optical fiber.
`FIG. 5 illustrates a fiber of FIG. 4 having an identifier
`embedded adjacent to one end of the fiber in accordance with
`an exemplary embodiment of the present invention. As shown
`in FIG. 5, the optical fiber 45 can comprise an outside surface
`43 including an identifier 43a. The identifier 43a is conve(cid:173)
`niently located proximate to an end of the optical fiber 45
`where it can remain visible during operation of the interlink
`44. The identifier 43a typically provides identification infor(cid:173)
`mation to facilitate mating of the optical fiber 45 with another
`optical fiber or waveguide structure. The identifier 43a pref(cid:173)
`erably includes sufficient space for the incorporation of a
`micro bar code, magnetic identifier or other identification
`information. To assist in appropriate alignment in mating of
`optical assemblies, the identifier 43a can identify the dimen(cid:173)
`sions and characteristics of the optical fiber 45. In addition,
`the core and polarization axes can be identified with respect to
`the location of the identifier 43a. In the alternative, testing and
`alignment infonnation can be provided by the identifier 43a
`to support alignment and testing operations. It will be appre(cid:173)
`ciated that the identifier 43a can be positioned at other loca(cid:173)
`tions along the optical fiber 45 so long as the identifier is
`visible to a user during operations of the interlink 44.
`In FIG. 6, a fiber interlink 60 has tapered (oblique) proxi-
`mal end faces on each of fibers 61, 62, 63, 64 and 65, which
`mate respectively with mating, tapered ports 61m, 62m, 63m,
`64m and 65m of a planar waveguide 69. Similarly, a fiber
`interlink 66 comprises proximal end faces on optical fibers
`that mate with opposing ports of the planar waveguide 69. The
`interlinks 60 and 66 operate in connection with the planar
`waveguide 69 to support an add-drop multiplexer application
`for adding and dropping optical signals of various wave(cid:173)
`lengths. The interlink 60 supports the drop function, whereas
`the interlink 66 supports the add function.
`
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`US 8,135,250 Bl
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`7
`For example, an optical signal input at an input port of the
`interlink 66 is passed by an optical fiber to the planar
`waveguide 69. A filter at the port 62m passes wavelength 1 of
`the optical signal to the interlink 60 and the remaining wave(cid:173)
`lengths of the optical signal are reflected at the port 62m. In
`turn, the fiber 61 carries the optical signal having the wave(cid:173)
`length 1 through the interlink 60 to the drop application.
`Similarly, the filter at the port 61m passes wavelength 2 to the
`optical fiber 62 of the interlink 60 and reflects the remaining
`wavelengths of the optical signal. In view of the cascading
`nature of the planar waveguide 69, similar drop functions are
`completed at the ports 63m, 64m, and 65m to complete the
`processing of the optical signal the by the add-drop multi(cid:173)
`plexer.
`FIG. 7 illustrates a cross-sectional view of waveguides in
`an interlink in accordance with an exemplary embodiment of
`a present invention. An interlink 72 comprises waveguides
`75f, 76f, and 77/ constructed from optical fibers of different
`configurations to provide channels for carrying optical sig(cid:173)
`nals. A portion of the optical fibers or waveguides 75f, 76f,
`and 77/ are embedded within an opaque block 74 comprising
`material opaque to the wavelengths of light expected to be
`transmitted through the embedded waveguides and light to
`which the interlink is exposed. Ports 75, 76, and 77 of the
`optical fibers 75f, 76f, and 77/ are positioned along a face
`surface 71 of the block 74. As discussed in connection with
`prior embodiments, the ports 75, 76, and 77 typically repre(cid:173)
`sent the proximal ends of the optical fibers 75f, 76f, and 77/
`Optical filters can be attached to the proximal ends of the
`optical fibers 75f, 76f, and 77/and adjacent to the ports 75, 76,
`and 77. The un-embedded portion of the optical fibers 75f,
`76f, and 77/ extend from a face surface 73 of the block 74. The
`distal end of each unembedded portion of the optical fibers
`75f, 76f, and 77/can include an optical filter such as optical
`filters 75a, 76a, 77a, and 77b.
`In summary, an exemplary embodiment of the present
`invention provides a modified fiber interlink for linking to and
`providing optical channels between at least one optical fiber
`system and at least one multi-channel planar optical
`waveguide. The waveguide includes a docking surface and
`ports optically opening on the docking surface to at least some
`of the optical channels. The interlink has a first face surface