US-12619033-B2 - Lens-based connector assemblies having precision alignment features and methods for fabricating the same

Abstract

Lens-based optical connector assemblies and methods of fabricating the same are disclosed. In one embodiment, a lens-based connector assembly includes a glass-based optical substrate includes at least one optical element within the optical substrate, and at least one alignment feature positioned at an edge of the glass-based optical substrate, wherein the at least one alignment feature is located within 0.4 μm of a predetermined position with respect to the at least one optical element along an x-direction and a y-direction. The lens-based connector assembly further includes a connector element including a recess having an interior surface, The interior surface has at least one connector alignment feature. The glass-based optical substrate is disposed within the recess such that the at least one alignment feature of the glass-based optical substrate engages the at least one connector alignment feature.

Inventors

• Jeffery Alan DeMeritt
• James Scott Sutherland

Assignees

• CORNING RESEARCH & DEVELOPMENT CORPORATION

Dates

Publication Date

20260505

Application Date

20231016

Claims (20)

1. 1 . A method of fabricating a glass-based optical substrate, the method comprising: forming at least one laser damage area within a glass sheet by applying a laser beam to the glass sheet, wherein the at least one laser damage area at least partially defines at least one alignment feature; etching the glass sheet in an etching solution to remove a portion of the glass-based optical substrate, thereby defining the at least one alignment feature; and singulating at least one glass-based optical substrate from the glass sheet such that the at least one alignment feature is located at an edge of the glass-based optical substrate.
2. 2 . The method of claim 1 , wherein: the at least one laser damage area comprises a plurality of damage areas along a plurality of intersecting dicing lines; and singulating the at least one glass-based optical substrate from the glass sheet comprises singulating a plurality of glass-based optical substrates by cutting the glass sheet along the plurality of intersecting dicing lines.
3. 3 . The method of claim 2 , wherein the cutting is performed by application of a dicing saw.
4. 4 . The method of claim 2 , wherein the cutting is performed by applying a cutting laser beam along the plurality of intersecting dicing lines, and then applying a bending force along the plurality of intersecting dicing lines.
5. 5 . The method of claim 1 , wherein the at least one damage area is rectangular.
6. 6 . The method of claim 1 , wherein the at least one damage area is diamond shaped.
7. 7 . The method of claim 1 , wherein the at least one damage area is circular.
8. 8 . The method of claim 1 , wherein the at least one alignment feature is a negative alignment feature.
9. 9 . The method of claim 8 , wherein the at least one alignment feature comprises a datum notch at the edge of the optical substrate.
10. 10 . The method of claim 9 , wherein the datum notch is rectangular.
11. 11 . The method of claim 9 , wherein the datum notch is a V-groove.
12. 12 . The method of claim 9 , wherein the datum notch is semi-circular.
13. 13 . The method of claim 9 , wherein the at least one alignment feature comprises a quarter-circle notch at one or more corners of the glass-based optical substrate.
14. 14 . The method of claim 13 , wherein the quarter-circle notch is located at a first corner and a second corner that is diagonally opposite from the first corner.
15. 15 . The method of claim 1 , wherein a cutting instrument that singulates the glass-based optical substrate from the glass sheet passes through an opening that is formed by the etching of the glass sheet such that the at least one alignment feature is a negative alignment feature.
16. 16 . The method of claim 15 , wherein the opening that is formed by the etching of the glass sheet forms a negative alignment feature on an additional glass-based optical substrate that is adjacent to the glass-based optical substrate in the glass sheet prior to the singulating.
17. 17 . The method of claim 1 , wherein the at least one alignment feature is a positive alignment feature.
18. 18 . The method of claim 1 , wherein the at least one alignment feature comprises both a positive feature and a negative feature.
19. 19 . The method of claim 18 , wherein the at least one alignment feature comprise a sinusoidal alignment feature.
20. 20 . The method of claim 1 , wherein a cutting instrument that singulates the glass-based optical substrate from the glass sheet cuts the glass sheet on each side of an opening that is formed by the etching of the glass sheet such that the at least one alignment feature is a positive alignment feature.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 17/344,329 filed on Jun. 10, 2021, which is a divisional of U.S. patent application Ser. No. 16/778,000 filed on Jan. 31, 2020, which is now U.S. Pat. No. 11,105,985 granted Aug. 31, 2021, the content of which is relied upon and incorporated herein by reference in its entirety, and the benefit of priority under 35 U.S.C. § 120 is hereby claimed. BACKGROUND Technical Field The present disclosure generally relates to optical connections and, more particularly, lens-based connector assemblies having alignment features fabricated by a laser process. Background Benefits of optical communication include extremely wide bandwidth and low noise operation. Because of these advantages, optical fiber is increasingly being used for a variety of applications, including, but not limited to, broadband voice, video, and data transmission. Connectors are often used in data center and telecommunication systems to provide service connections to rack-mounted equipment and to provide inter-rack connections. Optical interconnects in data centers use cables containing hundreds or thousands of optical fibers which are pulled through ducts as long as 2 km. These optical interconnects are often installed in ducts before they are spliced to shorter lengths of optical fiber previously factory-assembled to connectors. Joining such a large number of optical fibers to pigtails (for example 3,456) by fusion splicing generally produces joints with very low optical loss, but it is expensive because of the complexity of the work, the level of craft, and the long processing time required. Fusion splicing may also produce occasional high loss connections. Multi-fiber connectors built around precise injection molded hole arrays with 12, 16, 24, or 32 single-mode fibers are available but connectors with a higher number of fibers present extreme technical challenges. One such challenge is the need to have a precision fiber array in which a large number of fibers (e.g. 96 or more) are held in precise positions, with position errors smaller than 1 μm. This is beyond the capability of the connector molding processes used for current commercial products. Another challenge is related to the need to ensure positive contact between each fiber pair in a mated high fiber-count connector. This is typically accomplished by maintaining the height of all finished fibers to sub-micron accuracy relative to the ferrule end-face surface and applying a mating force to elastically accommodate any remaining error. Increasing the number of fibers moves these requirements, too, out of reach of present connector design and manufacturing by requiring unachievable precision of fiber protrusion on a large array and unacceptably high axial forces to successfully mate. Alternative structures and methods for optically coupling a large number of optical fibers together may be desired. SUMMARY In one embodiment, a lens-based connector assembly includes a glass-based optical substrate including at least one optical element within the optical substrate, and at least one alignment feature positioned at an edge of the glass-based optical substrate, wherein the at least one alignment feature is located within 0.4 μm of a predetermined position with respect to the at least one optical element along an x-direction and a y-direction. The lens-based connector assembly further includes a connector element including a recess having an interior surface, The interior surface has at least one connector alignment feature. The glass-based optical substrate is disposed within the recess such that the at least one alignment feature of the glass-based optical substrate engages the at least one connector alignment feature. In another embodiment, a method of fabricating a glass-based optical substrate include forming at least one laser damage area within a glass sheet by applying a laser beam to the glass sheet. The at least one laser damage area at least partially defines at least one alignment feature, and the at least one laser damage area is located within 0.4 μm of a predetermined position with respect to at least one optical element along an x-direction and a y-direction. The method further includes etching the glass sheet in an etching solution to remove a portion of the glass-based optical substrate, thereby defining the at least one alignment feature. The method also includes singulating at least one glass-based optical substrate from the glass sheet such that the at least one alignment feature is located at an edge of the glass-based optical substrate. It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated i