US-12625325-B2 - Optical systems for co-packaged applications

Abstract

An optical system is provided. The optical system includes an optical engine having a photonic integrated circuit (PIC) and an optical lens array, the optical lens array has a lens that is optically aligned with a waveguide in the PIC. The optical system also includes an optical connector optically aligned with the optical lens array to transfer optical signals between the optical connector and the waveguide in the PIC. The optical connector includes a ferrule and an optical fiber mated with the ferrule. The ferrule has a lens aligned with the lens of the optical lens array.

Inventors

• Norbert Schlepple
• Joyce J. M. Peternel
• Bing Shao

Assignees

• CISCO TECHNOLOGY, INC.

Dates

Publication Date

20260512

Application Date

20230726

Claims (17)

1. 1 . An optical system, comprising: an optical engine having a photonic integrated circuit (PIC) and an optical lens array having a first lens that is optically aligned with a waveguide in the PIC; and an optical connector optically aligned with the optical lens array to transfer optical signals between the optical connector and the waveguide in the PIC, the optical connector comprising a ferrule and an optical fiber mated with the ferrule, the ferrule comprising a second lens aligned with the first lens, wherein the optical lens array has a fine alignment feature and the ferrule includes a fine alignment feature, the fine alignment features of both the optical lens array and the ferrule are chamfers, and wherein the chamfers are shaped complementary to one another so as to facilitate optical alignment of the second lens of the ferrule with the first lens of the optical lens array.
2. 2 . The optical system of claim 1 , wherein the optical lens array is coupled with the PIC.
3. 3 . The optical system of claim 1 , wherein the optical lens array is coupled with the PIC so that an optical signal, when propagated, traverses from the optical fiber to an edge of the PIC.
4. 4 . The optical system of claim 1 , wherein the optical lens array is coupled with the PIC so that an optical signal, when propagated, traverses from the optical fiber to a top surface of the PIC along at least two different optical axes.
5. 5 . The optical system of claim 1 , wherein the optical lens array is coupled with the PIC so that an optical signal, when propagated, traverses from the optical fiber, through the second lens of the ferrule, through the first lens of the optical lens array, and to a focusing mirror of the optical lens array along a first optical axis, the focusing mirror is configured to focus the optical signal to a surface of the PIC along a second optical axis that is different than the first optical axis.
6. 6 . The optical system of claim 1 , wherein at least one of the optical lens array and the ferrule has a fine alignment feature that facilitates optical alignment of the second lens with the first lens.
7. 7 . The optical system of claim 1 , wherein the optical lens array defines an optical lens array cutout in which the first lens of the optical lens array is disposed, and wherein the optical lens array fine alignment feature is embodied as a chamfered edge along a perimeter of the optical lens array cutout.
8. 8 . The optical system of claim 1 , wherein the optical engine has a lid and a substrate that each include a coarse alignment feature that facilitate alignment of the ferrule relative to the optical lens array.
9. 9 . The optical system of claim 8 , wherein the coarse alignment feature of the lid and the coarse alignment feature of the substrate collectively define a perimeter guiding edge along a perimeter of an access opening that provides access to the optical lens array, the perimeter guiding edge being formed at least in part by chamfers.
10. 10 . The optical system of claim 1 , wherein the optical engine has a lid and a substrate that collectively define an interior in which the PIC extends, the lid has a support wall extending relative to the optical lens array, the support wall and the optical lens array collectively define a lens cavity in which a backfill material is disposed.
11. 11 . The optical system of claim 1 , wherein the ferrule is an expanded beam optics ferrule molded as a monolithic structure.
12. 12 . The optical system of claim 1 , wherein the ferrule includes a mechanically transferable (MT) ferrule coupled with an expanded beam optics (EBO) lens plate, the EBO lens plate includes the second lens of the optical connector.
13. 13 . The optical system of claim 12 , wherein the ferrule includes pins that couple the MT ferrule with the EBO lens plate, the pins have ends that extend beyond a lens plane defined by the second lens of the ferrule.
14. 14 . An optical engine, comprising: a lid having a support wall and a lid chamfer; a substrate having a substrate chamfer, the lid and the substrate defining an interior; a photonic integrated circuit (PIC) positioned at least in part within the interior; and an optical lens array coupled with the PIC and the support wall, the optical lens array having a first lens optically aligned with a waveguide of the PIC, and wherein the lid chamfer and the substrate chamfer are arranged to guide a ferrule of an optical connector toward the optical lens array and wherein the optical lens array has a chamfer arranged to guide a second lens of the ferrule into optical alignment with the first lens of the optical lens array.
15. 15 . An optical system, comprising: an optical engine having a photonic integrated circuit (PIC) and an optical lens array having a first lens that is optically aligned with a waveguide in the PIC; and an optical connector optically aligned with the optical lens array to transfer optical signals between the optical connector and the waveguide in the PIC, the optical connector comprising a ferrule and an optical fiber mated with the ferrule, the ferrule comprising a second lens aligned with the first lens, wherein the optical engine has a lid and a substrate that each include a coarse alignment feature that facilitate alignment of the ferrule relative to the optical lens array.
16. 16 . The optical system of claim 15 , wherein the optical lens array defines an optical lens array cutout in which the first lens of the optical lens array is disposed, and wherein the optical lens array has a fine alignment feature embodied as a chamfered edge along a perimeter of the optical lens array cutout.
17. 17 . The optical system of claim 15 , wherein the optical lens array has a fine alignment feature and the ferrule includes a fine alignment feature, the fine alignment features of both the optical lens array and the ferrule are chamfers, and wherein the chamfers are shaped complementary to one another so as to facilitate optical alignment of the second lens of the ferrule with the first lens of the optical lens array.

Description

TECHNICAL FIELD Embodiments presented in this disclosure generally relate to Co-Packaged Optical (CPO) applications, and more specifically, to optical systems for CPO applications. BACKGROUND A connectable interface between an optical connector and an optical engine for Co-Packaged Optics (CPO) applications can provide certain processing and application freedom for the optical engine, and in addition, a wide range of optical cables can be used. However, conventional optical connectors for such applications have largely needed to be customized or require brute-force application at the connectable interface to make a connection with an optical engine. Moreover, conventional connectors typically include guide pins for alignment with an optical engine, which can make material selection of components of the optical engine limited. Accordingly, there are certain challenges associated with a connectable interface between an optical connector and an optical engine. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate typical embodiments and are therefore not to be considered limiting; other equally effective embodiments are contemplated. FIG. 1 is a schematic view of an opto-electronic apparatus according to one or more embodiments. FIG. 2A is a schematic cross-sectional view of an optical system according to one or more embodiments. FIG. 2B is a close-up, cross-sectional view of a portion of the optical system of FIG. 2A, taken from Section B in FIG. 2A. FIG. 2C is a close-up, cross-sectional view of another embodiment of an optical connector and an optical engine that can be incorporated into the optical system of FIG. 2A. FIG. 2D is a close-up, cross-sectional view of yet another embodiment of an optical connector and an optical engine that can be incorporated into the optical system of FIG. 2A. FIG. 3A is a cross-sectional view of a portion of the optical engine of FIG. 2A. FIG. 3B is a top-looking-down cross-sectional view of a portion of the optical engine of FIG. 2A. FIG. 3C is a perspective view of a portion of the optical engine of FIG. 2A, with an optical lens array thereof shown transparent for illustrative purposes FIG. 4A is a schematic cross-sectional view of a portion of the optical system of FIG. 2A according to one or more embodiments FIG. 4B is a schematic cross-sectional view of a portion of an alternative configuration of the optical system of FIG. 2A according to one or more embodiments FIG. 4C is a schematic cross-sectional view of a portion of yet another alternative configuration of the optical system of FIG. 2A according to one or more embodiments. FIG. 5A is a schematic top view of an optical system having an EBO optical connector coupled with an optical engine. FIG. 5B is a schematic top view of an optical system having an MT-EBO optical connector coupled with an optical engine. FIG. 6A is a flow diagram for a method of assembling an optical engine according to one or more embodiments. FIG. 6B depicts an optical engine being assembled in accordance with the method of FIG. 6A. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially used in other embodiments without specific recitation. DESCRIPTION OF EXAMPLE EMBODIMENTS Overview Generally, optical systems for Co-Packaged Optics (CPOs) applications are provided in this disclosure. One embodiment presented in this disclosure is an optical system. The optical system includes an optical engine having a photonic integrated circuit (PIC) and an optical lens array, the optical lens array has a lens that is optically aligned with a waveguide in the PIC. The optical system also includes an optical connector optically aligned with the optical lens array to transfer optical signals between the optical connector and the waveguide in the PIC. The optical connector includes a ferrule and an optical fiber mated with the ferrule. The ferrule has a lens aligned with the lens of the optical lens array. One embodiment presented in this disclosure an optical engine. The optical engine includes a lid having a support wall and a lid chamfer. The optical engine also includes a substrate having a substrate chamfer. The lid and the substrate define an interior. The optical engine also includes a photonic integrated circuit (PIC) positioned at least in part within the interior. The optical engine further includes an optical lens array coupled with the PIC and the support wall. The optical lens array has a lens optically aligned with a waveguide of the PIC. The lid cha