Modular assembly for opto-electronic systems
A modular assembly for opto-electronic systems has a substrate on which various photonic integrated circuit (PIC) chips and electronic integrated circuit (EIC) chips are mounted. One or more waveguide (WG) chips mounted on the substrate align the optical communication between the PIC chips and fiber blocks for optical fibers. Preconfigured electrical connections in the substrate allow the PIC and EIC chips to communicate with one another and to communicate with solder bumps on the substrate for integration of the modular assembly with other electronic components.
1 . A system integrating a fiber block and a photonic integrated circuit (PIC) chip, the system comprising:
a waveguide (WG) chip disposed on a substrate between the fiber block and the PIC chip, the WG chip having a plurality of waveguides configured to transmit optical signals; and
mechanical structures for aligning the PIC chip and the WG chip, wherein:
the WG chip includes a first facet comprising a first light coupling surface providing a first light coupling with the fiber block by the plurality of waveguides and a second facet having a second light coupling surface providing a second light coupling with the PIC chip by the plurality of waveguides, and
the plurality of waveguides of the WG chip are configured to be coupled to second waveguides embedded between upper and lower surfaces of the PIC chip at the second light coupling surface,
each of the plurality of waveguides includes a first end disposed at the first light coupling surface and a second end disposed at the second light coupling surface, the first ends being respectively offset vertically from the second ends.
2 . The system according to claim 1 , wherein the first ends are respectively offset horizontally from the second ends.
3 . The system according to claim 2 , wherein the first ends of the plurality of waveguides are disposed at a bottom of the second light coupling surface and the second ends of the plurality of waveguides are disposed at a middle of the first light coupling surface.
4 . The system according to claim 1 , wherein one or more of the plurality of waveguides transmit the optical signals between the fiber block and the PIC chip.
5 . The system according to claim 1 , wherein the plurality of waveguides each comprise a refractive index that is different from a body of the WG chip.
6 . The system according to claim 1 , wherein the alignment features comprise:
an array of substrate bumpers on a surface of the substrate;
an array of PIC chip bumpers on a surface of the PIC chip that mechanically attach the PIC chip to the substrate and align the PIC chip with the WG chip; and
an array of WG chip bumpers on a surface of the WG chip that mechanically attach the WG chip to the substrate and align the WG chip with the PIC chip.
7 . The system according to claim 1 , wherein the wherein the first end is respectively vertically closer to the substrate than the second end.
8 . The system according to claim 1 , wherein:
the PIC chip and the WG chip are mounted on a first surface of the substrate; and
the second light coupling surface overlaps with the first surface of the substrate and extends along a direction perpendicular to the first surface of the substrate.
9 . The system according to claim 1 , wherein at least one of the first light coupling and the second light coupling comprises one of a butt-coupling, an evanescent coupling, and a radiative coupling.
10 . The system according to claim 6 , wherein the array of substrate bumpers comprises an array of solder bumps the array of WG chip bumpers comprises an array of solder bumps configured to align with the array of solder bumps provided on the surface of the substrate.
11 . The system according to claim 1 , wherein the optical signals are transmitted between the fiber block and the PIC chip, and through the WG chip.
12 . The system according to claim 1 , wherein the WG chip includes an alignment feature configured to enable passive fiber attachment between the PIC chip and optical fibers of the fiber block.
13 . The system according to claim 12 , wherein the alignment feature comprises at least of a pin hole and a slot configured to accept a one or more corresponding alignment pins on the fiber block.
14 . The system according to claim 1 , wherein the mechanical structures comprise one or more stands between the PIC and the substrate configured to vertically and/or horizontally align the PIC chip and the WG chip.
15 . The system according to claim 1 , wherein the mechanical structures comprise one or more trenches containing the PIC chip configured to vertically align the PIC chip with the WG chip.
16 . The system according to claim 1 , wherein the mechanical structures comprise one or more shoulders contacting the PIC chip configured to horizontally align the PIC chip with WG chip.