GLASS WAVEGUIDE ASSEMBLIES FOR OE-PCBs AND METHODS OF FORMING OE-PCBs

• US 20180217326A1
• Filed: 01/31/2017
• Published: 08/02/2018
• Est. Priority Date: 01/31/2017
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Inventors: Brusberg, Lars Martin Otfried
• Granted Patent: US 10,459,160 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2006/12038 Glass (SiO2 based materials)
• CPC Class Codes: G02B 2006/12102 Lens
• CPC Class Codes: G02B 2006/12183 Ion-exchange
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/1345 using ion exchange ion exchange in glass C03C21/00
• CPC Class Codes: G02B 6/30 for use between fibre and thin-film device
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/428 containing printed circuit boards [PCB]
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H05K 1/0274 Optical details, e.g. printed circuits comprising integral optical means H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42
• CPC Class Codes: H05K 1/18 Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/053 Tails
• CPC Class Codes: H05K 2201/10446 Mounted on an edge

Abstract

The glass waveguide assembly includes a substrate with glass optical waveguides formed in the body of the glass substrate without adding or removing any glass from the substrate body. The glass optical waveguides run generally from a front-end section to a back-end section. A protective coating is formed over at least a portion of the top surface of the glass substrate where the glass optical waveguides reside. Optical connectors are formed at or adjacent the back end at corresponding connector regions. Each connector includes an end portion of at least one of the glass optical waveguides. In some configurations, the glass waveguide assembly includes a bend section that facilitates forming an optical interconnection in a photonic system between an optical-electrical printed circuit board and photonic integrated circuit.

Claims

1. A glass waveguide assembly, comprising:

a glass substrate comprising a body with a front-end section having a front end, a back-end section having a back end, a top surface, a bottom surface, and at least one connector region adjacent the back end;

at least one glass optical waveguide formed in the body of the glass substrate and that runs generally from the front-end section to the back-end section;

a protective coating formed over at least a portion of the top surface adjacent to the at least one glass optical waveguide; and

at least one optical connector formed at or adjacent the back end at the at least one connector region and that includes an end portion of the at least one glass optical waveguide.

2. The glass waveguide assembly according to claim 1, wherein the body has a substantially constant thickness in the range between 20 microns and 500 microns.

3. The glass waveguide assembly according to claim 2, wherein the body has a length measured between the front end and the back end in the range of between 2 centimeters and 10 centimeters.

5. The glass waveguide assembly according to claim 1, wherein the bend section causes the front-end section and the back-end section of the glass substrate to reside in parallel planes separated by a distance of no greater than 4 millimeters.

6. The glass waveguide assembly according to claim 1, wherein the at least one glass optical waveguide comprises multiple glass optical waveguides, and wherein at least one of the front-end and back-end sections of the glass substrate includes slots that define waveguide sections, each waveguide section comprising at least one of the multiple glass optical waveguides, wherein one or more of the waveguide sections are independently flexible.

7. The glass waveguide assembly according to claim 1, wherein the at least one glass optical waveguide comprises multiple glass optical waveguides, wherein the at least one optical connector comprises multiple optical connectors, and wherein each optical connector of the multiple optical connectors terminate at least one of the multiple glass optical waveguides.

8. The glass waveguide assembly according to claim 1, wherein the protective coating covers the bottom surface of the glass substrate at least up to the at least one connector region.

9. The glass waveguide assembly according to claim 1, wherein the protective cover does not cover the at least one connector region.

10. The glass waveguide assembly according to claim 1, wherein the glass substrate comprises an ion-exchangeable material.

11. The glass waveguide assembly according to claim 1, wherein the glass substrate comprises a K⁺ ion-exchanged glass.

12. The glass waveguide assembly according to claim 1, further comprising at least one conducting feature formed either on the top surface of the glass substrate or on a top surface of the protective coating.

13. The glass waveguide assembly according to claim 1, further comprising at least one of a hole, a perforation, a through hole and a polymer-filled via.

14. The glass waveguide assembly according to claim 1, further comprising at least one of a cut-out and a polymer-filled cut-out.

15. The glass waveguide assembly according to claim 1, wherein the at least one connector has an MT configuration.

16. The glass waveguide assembly according to claim 1, wherein the at least one connector comprises a ferrule having an interior that encloses the connector area.

17. The glass waveguide assembly according to claim 1, wherein the at least one connector comprises a microlens array having at least one microlens element disposed immediately adjacent an end of the at least one glass optical waveguide.

18. An optical-electrical printed circuit board (OE-PCB), comprising:

the glass waveguide assembly according to claim 1; and

a printed circuit board (PCB) that operably supports the glass waveguide assembly.

19. The OE-PCB according to claim 18, wherein the PCB operably supports a photonic integrated circuit (PIC) that includes at least one PIC waveguide, and wherein the glass waveguide assembly is operably supported adjacent a top surface of the PCB in a fly-over configuration such that the front-end section of the glass waveguide assembly includes a bend and wherein the at least one glass optical waveguide is optically coupled to the at least one PIC waveguide.

20. The OE-PCB according to claim 18, wherein the PCB operably supports a photonic integrated circuit (PIC) that includes at least one PIC waveguide, and wherein the back-end section of the glass waveguide assembly is embedded within the PCB and the front-end section of the glass waveguide assembly includes a bend section and is disposed relative to the PIC such that the at least one glass optical waveguide is optically coupled to the at least one PIC waveguide.

21. The OE-PCB according to claim 18, wherein:

the PCB comprises conductive layers spaced apart by insulating and at least a portion of the glass waveguide assembly is embedded in the PCB, different conductive layers of the PCB being in electrical communication through at least one conductive via formed in the glass waveguide assembly; and

the PCB operably supports a photonic integrated circuit (PIC) through an interposer, the PIC comprising at least one PIC waveguide, wherein the at least one glass optical waveguide is in optical communication with the at least one PIC waveguide.

22. The OE-PCB according to claim 21, wherein the entire glass waveguide assembly is embedded within the PCB and wherein the at least one glass optical waveguide is in optical communication with the at least one PIC waveguide through at least one optical via that includes at least one light-turning structure.

23. The OC-PCB according to claim 21, wherein the at least one connector resides at or immediately adjacent an end of the PCB.

24. The OE-PCB according to claim 18, wherein:

the PCB operably supports a photonic integrated circuit (PIC) that includes at least one photonic device;

the back-end section of the glass waveguide assembly is embedded within the PCB and the front-end section includes a bend section and is disposed relative to the PIC such that the at least one glass optical waveguide of the glass waveguide assembly is optically coupled to the at least one photonic device.

25. The OE-PCB according to claim 18, wherein:

the PCB comprises conductive layers spaced apart by insulating layers;

at least a portion of the glass waveguide assembly is embedded in the PCB and includes at least one conductive via;

different conductive layers of the PCB are in electrical communication through the at least one conductive via; and

a photonic integrated circuit (PIC) is operably supported by the PCB through an interposer, the PIC comprising at least one photonic device, and wherein the at least one glass optical waveguide is in optical communication with the at least one photonic device.

26. The OE-PCB according to claim 18, wherein the at least one connector comprises a ferrule that defines an MT configuration.

4. The glass waveguide assembly according to claim 4, wherein the body is flexible to form a bend section having a bend radius in the range from 5 millimeters to 30 millimeters.

27. A glass waveguide assembly, comprising:

a glass substrate defined by a body having a top surface, a front-end section with a front-end and a back-end section with a back end;

one or more glass optical waveguides, with each glass optical waveguide having respective front and back ends and being formed within the body of the glass substrate;

one or more connectors operably arranged at the back ends of the glass optical waveguides to define an exposed portion of the glass substrate; and

a protective coating made of a dielectric material and that coats at least the exposed portion of the top surface of the glass substrate.

28. The glass waveguide assembly according to claim 27, wherein at least one of the front-end and back-end sections of the glass substrate includes slots that define waveguide sections, one or more of the waveguide sections comprising at least one of the one or more glass optical waveguides, wherein the waveguide sections are independently flexible.

29. The glass waveguide assembly according to claim 27, wherein the glass substrate comprises an ion-exchangeable material.

30. The glass waveguide assembly according to claim 27, further comprising at least one conducting feature formed either on the top surface of the glass substrate or on a top surface of the protective coating.

31. The glass waveguide assembly according to claim 27, further comprising at least one of:

an insulating via, a conducting via, a through hole, a conducting line, a conducting pad, a slot, cut-out, a perforation, a fiducial, and an alignment mark.

32. The glass waveguide assembly according to claim 27, wherein the at least one connector has an MT configuration.

33. The glass waveguide assembly according to claim 27, wherein at least one of the one or more connectors comprises a microlens array having at least one microlens element, and wherein the at least one microlens element is arranged immediately adjacent corresponding ends of the glass optical waveguides.

34. A method of forming an optical-electrical printed circuit board (OE-PCB) that includes a printed circuit board and a photonic integrated circuit (PIC) having at least one photonic device, the method comprising:

forming from a glass substrate having a body a glass waveguide assembly having a front-end section with a front-end and a back-end section with a back end, comprising;

forming at least one glass optical waveguide having respective front and back ends and being formed by selectively modifying the glass of the glass body using at least one of an ion-exchange process and a laser-writing process;

connectorizing the back end of the at least one glass optical waveguide using at least one connector; and

coating at least a portion of the top surface of the glass substrate with a protective coating made of a dielectric material;

supporting at least the back-end section of the glass waveguide assembly within or adjacent the printed circuit board; and

disposing the front-end section of the glass waveguide assembly relative to the PIC so that the at least one glass optical waveguide is in optical communication with the at least one photonic device.

35. The method according to claim 34, wherein the at least one photonic device comprises at least one PIC waveguide, and wherein evanescent coupling between the at least on glass optical waveguide and the at least one PIC waveguide provides the optical communication between the at least one glass optical waveguide and the at least one photonic device.

36. The method according to claim 34, further comprising:

adding at least one OE-PCB feature or component to the coated portion of the glass substrate, wherein the at least one OE-PCB feature or component is selected from the group of OE-PCB features or components comprising;

an insulating via, a conducting via, a through hole, a conducting line, a conducting pad, a slot, a cut-out, a polymer-filled cut-out, a perforation, a fiducial, and an alignment mark.

37. The method according to claim 34, wherein an optical via provides the optical communication between the at least one glass optical waveguide and the at least one photonic device.

38. The method according to claim 34, wherein one or more support members support the glass waveguide array adjacent an upper surface of the PCB in a fly-over configuration.

39. The method according to claim 34, further comprising:

embedding the waveguide assembly within the PCB with the one or more connectors residing adjacent a back end of the PCB.

40. The method according to claim 34, wherein the PCB includes a recess, and further comprising flexing the front-end section of the waveguide assembly from an initial position within the recess, to an intermediate position away from the PIC and to a final position that establishes the optical communication between the at least one glass optical waveguide and the at least one photonic device.

41. The method according to claim 34, wherein the glass substrate assembly defines a first glass substrate assembly and further comprising supporting a second glass substrate assembly within or adjacent the PCB.

42. The method according to claim 34, wherein the at least one glass optical waveguide comprises multiple glass optical waveguides, the method further comprising:

forming slots in the back-end section of the glass waveguide assembly to define independently flexible waveguide sections that each includes at least one of the multiple glass optical waveguides, with each of the waveguide sections at the back-end section being connectorized.

43. The method according to claim 42, further comprising connectorizing the front-end of the glass waveguide assembly with a front-end connector.

44. The method according to claim 34, wherein the at least one glass optical waveguide comprises multiple glass optical waveguides, and wherein the front ends of the multiple glass optical waveguides define a first pitch and wherein the back ends of the multiple glass optical waveguides define a second pitch.

45. The method according to claim 44, wherein at least one of the first and second pitches is 125 microns or 250 microns.

46. The method according to claim 44, wherein the first and second pitches are the same.

47. The method according to claim 34, wherein the act of connectorizing includes operably incorporating a microlens array to the at least one connector.

48. The method according to claim 34, wherein the act of connectorizing includes forming the at least one connector as an MT-type connector or an MPO-type connector.

49. The method according to claim 34, wherein the act of connectorizing includes operably disposing a ferrule at the back-end section of the glass waveguide assembly.

50. The method according to claim 34, wherein the act of forming the at least one glass optical waveguide includes not removing glass from the body of the glass substrate or adding glass to the body of the glass substrate.