Optical receiver using a photodetector with a self-aligned lens

Patent metadata

Field	Value
Publication number	US-9869833-B2
Application number	US-201514874221-A
Country	US
Kind code	B2
Filing date	Oct 2, 2015
Priority date	Oct 2, 2015
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A constructed photodetector, an optical receiver, and a receiver unit in an optical communication system are disclosed. One example of the disclosed constructed photodetector includes an optoelectronic element having an active area that converts light having a wavelength of interest into electrical signals and a substrate on a face that opposes the active area, where the substrate is non-transparent to light having the wavelength of interest. The constructed photodetector further includes a lens-chip that is at least partially transparent to light having the wavelength of interest, where the lens-chip includes a first side and an opposing second side, where the first side of the lens-chip includes an integrated lens, and where the second side of the lens-chip includes one or more electrical traces. The constructed photodetector further includes at least one connector that provides a physical and electrical connection between the optoelectronic element and the lens-chip.

First claim

What is claimed is:

1. An optical receiver, comprising:
a constructed photodetector configured to receive light having a wavelength of interest and convert the received light into electrical signals, the constructed photodetector comprising:
an optoelectronic element having a first face including an active area that converts the light into electrical signals and a body, wherein the body is substantially opaque to light having the wavelength of interest;
a lens chip that is at least partially transparent to light having the wavelength of interest, wherein the lens chip comprises a first side and an opposing second side, wherein the first side of the lens-chip comprises a lens, and wherein the second side of the lens-chip comprises one or more electrical traces; and
at least one connector that provides a physical connection between the first face of the optoelectronic element and the second side of the lens-chip; and

a secondary optical element mounted to a circuit carrier, wherein the secondary optical element is optically aligned with the lens-chip via solder balls provided on the circuit carrier.

2. The optical receiver of claim 1 , wherein electrical signals produced at the first face of the optoelectronic element are carried to the one or more electrical traces of the lens-chip via the at least one connector.

3. The optical receiver of claim 1 , wherein the at least one connector provides an optical alignment between the lens of the lens-chip and the active area of the optoelectronic element.

4. The optical receiver of claim 3 , wherein the lens is integral to the lens-chip.

5. The optical receiver of claim 1 , wherein the circuit carrier is attached to the lens-chip.

6. The optical receiver of claim 5 , wherein the solder balls facilitate optical alignment between the secondary optical element and the lens of the lens-chip.

7. The optical receiver of claim 5 , wherein the circuit carrier is connected to the lens-chip via at least one bonding wire.

8. The optical receiver of claim 5 , wherein the circuit carrier is connected to the lens-chip via one or more connectors, wherein the one or more connectors that connect the circuit carrier to the lens-chip include solder balls that are attached directly to the one or more electrical traces of the lens-chip.

9. The optical receiver of claim 1 , wherein the circuit carrier comprises at least one window.

10. The optical receiver of claim 9 , wherein the at least one window allows the light to pass therethrough.

11. The optical receiver of claim 9 , wherein the at least one window at least partially contains the optoelectronic element therein.

12. The optical receiver of claim 1 , wherein the wavelength of interest is greater than 800 nm, wherein the lens-chip comprises Gallium Phosphide, wherein the lens comprises Gallium Phosphide, and wherein the optoelectronic element comprises a PIN photodiode.

13. The optical receiver of claim 1 , wherein the optoelectronic element is flip-chip mounted to the lens-chip.

14. A constructed photodetector for use in an optical receiver, the constructed photodetector comprising:
an optoelectronic element having an active area that converts light having a wavelength of interest into electrical signals and a substrate supporting the active area, wherein the substrate is non-transparent to light having the wavelength of interest;
a lens-chip that is at least partially transparent to light having the wavelength of interest, wherein the lens-chip comprises a first side and an opposing second side, wherein the first side of the lens-chip comprises an integrated lens, and wherein the second side of the lens-chip comprises one or more electrical traces;
at least one connector that provides a physical and electrical connection between the optoelectronic element and the lens-chip; and
a secondary optical element mounted to the at least one connector and aligned with the integrated lens of the lens-chip with a plurality of solder bumps provided on the at least one connector.

15. The constructed photodetector of claim 14 , wherein the plurality of solder bumps also connect a face of the optoelectronic element having the active area with the one or more electrical traces of the lens-chip.

16. The constructed photodetector of claim 14 , wherein the at least one connector provides an optical alignment between the integrated lens of the lens-chip and the active area of the optoelectronic element.

17. The constructed photodetector of claim 14 , wherein the secondary optical element comprises at least one of a wavelength demultiplexer, a focusing lens, and a collimating lens, wherein the wavelength of interest is between 800 nm and 950 nm, wherein the lens-chip comprises Gallium Phosphide, wherein the integral lens is formed via etching, and wherein the optoelectronic element comprises a PIN photodiode.

18. The constructed photodetector of claim 14 , wherein the optoelectronic element is flip-chip mounted to the lens-chip.

19. A transceiver unit in an optical communication system, comprising:
a constructed element configured to receive or produce light having a wavelength of interest, the constructed element comprising:
an optoelectronic element having a first face including an active area that converts the light into electrical signals or electrical signals into light and an opposing second face, wherein the second face is substantially opaque to light having the wavelength of interest;
a lens-chip that is at least partially transparent to light having the wavelength of interest, wherein the lens-chip comprises a first side and an opposing second side, wherein the first side of the lens-chip comprises an integral lens, and wherein the second side of the lens-chip comprises one or more electrical traces; and
at least one connector that provides a physical connection between the first face of the optoelectronic element and the second side of the lens-chip;

a circuit carrier onto which the constructed element is mounted; and
a secondary optical element that is also mounted to the circuit carrier and which is optically aligned with the active area via one or more alignment elements.

20. The transceiver unit of claim 19 , wherein the one or more alignment elements include at least one of mechanical fittings and solder bumps, wherein the wavelength of interest is between approximately 800 nm and 950 nm, and wherein the optical communication system supports communication data rates of at least 20 GHz.

Assignees

• Avago Technologies General Ip

Inventors

• Wang Tak Kui
• Chen Ye
• Su Chung-Yi
• Yashar Frank

Classifications

• G02B6/4238 Primary

  Soldering · CPC title

• G02B6/4292

  the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements · CPC title

• G02B6/4232

  using the surface tension of fluid solder to align the elements, e.g. solder bump techniques (flip-chip mounting techniques in assembly of semiconductor devices H10W72/072) · CPC title

• H04B10/60

  Receivers · CPC title

• G02B6/4204

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