Photodetectors with controllable resonant enhancement

Patent metadata

Field	Value
Publication number	US-2021013356-A1
Application number	US-201916569617-A
Country	US
Kind code	A1
Filing date	Sep 12, 2019
Priority date	Jul 12, 2019
Publication date	Jan 14, 2021
Grant date	—

Abstract

Resonant cavity photodetector structures which integrate photodetection and filtering capabilities is described. A resonant cavity photodetector structure generally can comprise a region including a resonator, and an absorption region that can be integrated into a cavity of the resonator. The resonator can perform filtering that is suitable for high-bandwidth optical communications, such as Dense Wavelength Multiplexing (DWDM). In some cases, the resonator is a microring resonator. An absorption region can include a photodiode which performs optical energy detection acting as a photodetector, such as an avalanche photodiode (APD) wherein the photodiode. A coupling distance between the resonator region and the absorption region can be controlled, which allows control of a coupling strength between an optical mode of the resonator and the absorption region such that a quality factor (Q-factor) can be tuned. Thus, by adjusting the Q-factor, the resonant cavity photodetector structure can be tuned to achieve a desirable performance.

First claim

What is claimed is:

1 . A resonant cavity photodetector structure device having photodetection and filtering capabilities, comprising:
a resonator region comprising a resonator photonic element, wherein the resonator photonic element performs resonance wavelength-based filtering to provide the filtering capabilities of the resonator photodetector device; an absorption region adjacent to the resonator region and comprising photodiode photonic elements, wherein the photodiode photonics elements perform optical energy detection to provide the photodetection capabilities; and a coupling distance between the resonator region and the absorption region, wherein the coupling distance is selectively adjusted to control a coupling strength between an optical mode associated with the resonator region and the absorption region and correspondingly control a quality factor (Q-factor) of the filtering capabilities.

2 . The device of claim 1 , wherein the photodiode photonic elements comprise an avalanche photodiode (APD).

3 . The device of claim 2 , wherein the resonator photonic element comprises a resonant cavity.

4 . The device of claim 3 , wherein the absorption region comprising the APD is positioned within the cavity of the resonator photonic element.

5 . The device of claim 3 , wherein the resonator photonic element comprises at least one of: a microring resonator, a Fabry Perot, and a photonic crystal.

6 . The device of claim 5 , wherein the resonator photonic element is a microring resonator comprising a ring waveguide evanescently coupled to a bus waveguide.

7 . The device of claim 6 , wherein the absorption region comprising the APD is positioned within an area bordered by a diameter of the ring waveguide.

8 . The device of claim 7 , wherein the coupling distance being selectively adjusted to increase a physical separation between an edge of the ring waveguide and the absorption region corresponds to lowering the coupling strength between an optical mode and the absorption region.

9 . The device of claim 2 , wherein the APD is a separate-absorption-charge-and-multiplication (SACM) APD and a separate section of the SACM APD is positioned on a section of the ring waveguide.

10 . The of device of claim 9 , wherein a physical size and an absorption layer thickness of the SACM APD are reduced such that a responsivity and a response speed of the device are increased.

11 . The device of claim 1 , wherein the coupling distance is selectively adjusted to control the Q-factor such that a channel spacing between 50 GHz and 200 GHz is supported in a dense wavelength division multiplexing (DWDM) system.

12 . The device of claim 2 , wherein the APD comprises a silicon geranium (SiGe) APD.

13 . A resonator photodetector device having photodetection and filtering capabilities, comprising:
a resonator providing the filtering capabilities of the resonator photodetector device; and a photodetector positioned on a portion of the resonator and providing the photodetection capabilities of the photonic resonator device, wherein a photodetector size associated with the photodetector is selectively adjusted to be smaller than a resonator size associated with the resonator and reduce the overall size of the resonator photodetector device and correspondingly control a carrier transit time associated with a speed of the resonator photodetector device.

14 . The device of claim 13 , wherein the resonator is a microring resonator comprising a ring waveguide evanescently coupled to a bus waveguide.

15 . The device of claim 14 , wherein the photodetector comprises an intrinsic silicon layer that is positioned on top of a portion of the ring waveguide.

16 . The device of claim 15 , wherein the photodetector size is selectively adjusted to provide a capacitance that further controls the speed of the resonator photodetector device.

17 . A resonant cavity photodetector structure device having photodetection and filtering capabilities, comprising:
a resonator region comprising a resonator photonic element, wherein the resonator photonic elements perform resonance wavelength-based filtering to provide the filtering capabilities of the resonator photodetector device; an absorption region adjacent to the resonator region and comprising an avalanche photodiode (APD) performing the photodetection capabilities; and a coupling distance between the resonator region and the absorption region, wherein the coupling distance is selectively adjusted to control a coupling strength between an optical mode associated with the resonator region and the absorption region and correspondingly control a quality factor (Q-factor) of the filtering capabilities.

18 . The device of claim 17 , wherein the resonator photonic element comprises a microring resonator further comprising a ring waveguide evanescently coupled to a bus waveguide.

19 . The device of claim 18 , wherein the absorption region comprising the APD is positioned outside of an area bordered by a diameter of the ring waveguide.

20 . A resonant cavity photodetector structure device having photodetection and filtering capabilities, comprising:
a Fabry Perot resonator cavity, wherein the Fabry-Perot resonator cavity provides the filtering capabilities of the resonator photodetector device; an absorption region positioned between the Fabry Perot resonator cavity and comprising photodiode photonic elements, wherein the photodiode performs optical energy detection to provide the photodetection capabilities.

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Huang Zhihong
• Zeng Xiaoge
• Sorin Wayne Victor

Classifications

• H10F77/413

  directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42) · CPC title

• H10F77/959

  for devices working in avalanche mode · CPC title

• H10F30/2255

  in which the active layers form heterostructures, e.g. SAM structures · CPC title

• H10F77/147

  Shapes of bodies · CPC title

• H10F30/225 Primary

  the potential barrier working in avalanche mode, e.g. avalanche photodiodes · CPC title