Photodiode (PD) array with integrated back-side lenses and a multi-channel transceiver module implementing same

Patent metadata

Field	Value
Publication number	US-10950651-B2
Application number	US-201816202813-A
Country	US
Kind code	B2
Filing date	Nov 28, 2018
Priority date	Nov 28, 2018
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

The present disclosure is generally directed to an optical transceiver that includes a multi-channel on-board ROSA arrangement that includes an optical demultiplexer, e.g., an arrayed waveguide grating (AWG) and an array of photodiodes disposed on a same substrate. The array of photodiodes may be optically aligned with an output port of the optical demultiplexer and be configured to detect channel wavelengths and output a proportional electrical signal to an amplification circuit, e.g., a transimpedance amplifier. Each of the photodiodes can include an integrated lens configured to increase the alignment tolerance between the demultiplexer and the light sensitive region such that relatively imprecise bonding techniques, e.g., die bonding, may be utilized while still maintaining nominal optical power.

First claim

What is claimed is:

1. An optical transceiver module, the optical transceiver module comprising:
a substrate having a first end that extends to a second end, the substrate having at least a first mounting surface; and
an on-board receiver optical subassembly (ROSA) arrangement, the on-board ROSA arrangement comprising:
an array of photodiodes mounted to the first mounting surface of the substrate;
an optical demultiplexer mounted to the first mounting surface of the substrate, the optical demultiplexer having an optical output port aligned and optically coupled to the array of photodiodes; and
wherein each photodiode of the array of photodiodes include an integrated lens disposed thereon such that the integrated lens is substantially flush with a top surface defining each photodiode to increase an alignment tolerance between the optical demultiplexer and a light sensitive region of each photodiode of the array of photodiodes.

2. The optical transceiver module of claim 1 , wherein the optical demultiplexer is configured to receive a signal having multiple channel wavelengths and output at least five different channel wavelengths.

3. The optical transceiver module of claim 1 , wherein the array of photodiodes are mounted to the first mounting surface by way of a photodiode submount.

4. The optical transceiver module of claim 3 , wherein the array of photodiodes include first and second 1×4 arrays of photodiodes, and wherein the photodiode submount is configured to couple to the first and second 1×4 arrays of photodiodes, and wherein the photodiode submount is formed as a single piece and includes a spacer that separates the first and second 1×4 arrays by a distance that aligns each of the first and second 1×4 arrays of photodiodes with associated output ports of the optical demultiplexer.

5. The optical transceiver module of claim 1 , further comprising first and second amplification circuits mounted to the first mounting surface of the substrate, the first and second amplification circuits electrically coupled to the array of photodiodes.

6. The optical transceiver module of claim 1 , wherein the optical demultiplexer comprises an arrayed waveguide grating (AWG).

7. The optical transceiver module of claim 1 , wherein each photodiode of the array of photodiodes provides the increased alignment tolerance based on a position of a lens integrated into each photodiode.

8. The optical transceiver module of claim 1 , wherein the substrate comprises a printed circuit board assembly (PCBA).

9. An optical transceiver, the optical transceiver comprising:
a housing defining a cavity for receiving an optical transceiver module; and
an optical transceiver module disposed at least partially within the cavity of the housing, the optical transceiver module comprising:
a substrate having a first end that extends to a second end, the substrate having at least a first mounting surface;
an on-board receiver optical subassembly (ROSA) arrangement, the on-board ROSA arrangement comprising:
an array of photodiodes mounted to the first mounting surface of the substrate;
an arrayed waveguide grating (AWG) mounted to the first mounting surface of the substrate, the AWG having an optical output port aligned and optically coupled to the array of photodiodes; and
wherein each photodiode of the array of photodiodes include an integrated lens disposed thereon such that the integrated lens is substantially flush with a top surface defining each photodiode to increase an alignment tolerance between the AWG and a light sensitive region of each photodiode of the array of photodiodes;

a transmitter optical subassembly (TOSA) arrangement mounted to the substrate.

10. The optical transceiver of claim 9 , wherein the AWG is configured to receive a signal having multiple channel wavelengths and output at least five different channel wavelengths.

11. The optical transceiver of claim 9 , wherein the array of photodiodes are mounted to the first mounting surface by way of a photodiode submount.

12. The optical transceiver of claim 11 , wherein the array of photodiodes include first and second 1×4 arrays of photodiodes, and wherein the photodiode submount is configured to couple to the first and second 1×4 arrays of photodiodes and includes a spacer that separates the first and second 1×4 arrays of photodiodes by a distance that aligns each of the first and second 1×4 arrays of photodiodes with associated output ports of the AWG.

13. The optical transceiver of claim 9 , further comprising first and second amplification circuits mounted to the first mounting surface of the substrate, the first and second amplification circuits electrically coupled to the array of photodiodes.

14. The optical transceiver of claim 9 , wherein the AWG includes a base portion that couples the AWG to the first mounting surface and a body that defines at least one light path for separating channel wavelengths and optically coupling the AWG to the array of photodiodes, the at least one light path not extending through the base portion.

15. The optical transceiver of claim 9 , wherein the increased alignment tolerance is based on a position of each integrated lens relative to the light-sensitive region.

16. A photodiode device for use in an optical subassembly, the photodiode device comprising:
a base having at least first and seconds sides opposite each other;
a plurality of electrical contacts disposed on the first side;
a light-sensitive region; and
an integrated lens disposed on the second side over the light-sensitive region such that the integrated lens is substantially flush with a top surface defining each photodiode to increase an alignment tolerance between an optical demultiplexer and the light-sensitive region of the photodiode.

17. The photodiode device of claim 16 , wherein the integrated lens at least doubles the alignment tolerance.

Assignees

• Applied Optoelectronics Inc

Inventors

• Wang Hsiu-Che
• Marentes Elsie
• Li Qin

Classifications

• H10W90/00

  Package configurations · CPC title

• H10F39/18 Primary

  Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors · CPC title

• H10F39/103 Primary

  the at least one element covered by H10F30/00 having potential barriers, e.g. integrated devices comprising photodiodes or phototransistors · CPC title

• G02B6/421

  the intermediate optical component consisting of a short length of fibre, e.g. fibre stub · CPC title

• G02B6/4204

  the coupling comprising intermediate optical elements, e.g. lenses, holograms (encapsulated active devices H01S5/02208) · CPC title