Waveguide optically pre-amplified detector with passband wavelength filtering

• US 8,098,969 B2
• Filed: 12/08/2009
• Issued: 01/17/2012
• Est. Priority Date: 12/08/2009
• Status: Active Grant

• Current Assignee: OneChip Photonics, Inc.
• Original Assignee: OneChip Photonics, Inc.
• Inventors: Tolstikhin, Valery, Wu, Fang, Watson, Christopher, Logvin, Yury, Pimenov, Kirill
• Primary Examiner(s): Pak, Sung
• Application Number:
  US12/632,933
• Publication Number:
  US 20110135314A1
• Time in Patent Office: 770 Days
• Field of Search: None
• US Class Current: 385/14
• CPC Class Codes: G02B 2006/12121 Laser
• CPC Class Codes: G02B 2006/12123 Diode
• CPC Class Codes: G02B 2006/12195 Tapering
• CPC Class Codes: H01S 5/0262 Photo-diodes, e.g. transceiver devices, bidirectional devices H01S5/0265 takes precedence
• CPC Class Codes: H01S 5/1014 Tapered waveguide, e.g. spotsize converter H01S5/1064 takes precedence
• CPC Class Codes: H01S 5/5018 using two or more amplifiers or multiple passes through the same amplifier

Abstract

The invention describes an integrated-photonics arrangement, implementable in a multi-guide vertical integration (MGVI) structure composed from III-V semiconductors and grown in one epitaxial growth run, allowing for the integration of semiconductor optical amplifier (SOA) and PIN photodetector (PIN) structures within a common wavelength-designated waveguide of the plurality of the vertically integrated wavelength-designated waveguides forming the MGVI structure. The integration includes a wavelength filter integrated between the SOA and PIN to reduce noise within the PIN arising from ASE generated by the SOA. In exemplary embodiments of the invention, the wavelength filter is integrated into MGVI structure either within a common wavelength designated waveguide or within the wavelength-designated waveguide. Further in other embodiments the wavelength filter is provided by a thin-film filter abutting a facet of the integrated-photonics arrangement wherein optical signals are coupled by optical waveguides and/or additional optical elements such as a multimode interference device.

Claims

1. A photonic component comprising:

a) an epitaxial semiconductor structure grown in a III-V semiconductor material system in a single growth step upon a substrate comprising a common designated waveguide for supporting propagation of optical signals within a predetermined first wavelength range and at least one of a plurality of wavelength designated waveguides vertically disposed in order of increasing wavelength bandgap, each of the plurality of wavelength designated waveguides supporting a predetermined second wavelength range, each of the predetermined second wavelength ranges being within the predetermined first wavelength range;

b) an optical input port for receiving optical signals within the first wavelength range;

c) a first filter comprising at least a first output port and a second output port and characterized by at least a first passband width, the filter optically coupled to the optical input port for receiving optical signals within the first wavelength range and for providing a first predetermined portion of the received optical signals to the first output port, the first predetermined portion of the received optical signals being determined in dependence upon at least the first passband width;

d) an optical amplifier comprising at least a gain section formed within the one of the plurality of wavelength designated waveguides, a first contact for forward biasing the optical amplifier, and a third output port, the optical amplifier optically coupled to the first output port for receiving the first predetermined portion of the received optical signals and providing amplified filtered optical signals to the third output port;

e) a second filter comprising at least a fourth output port and a fifth output port and characterized by at least a second passband width, the filter optically coupled to the third output port of the optical amplifier and for providing a first predetermined portion of the amplified filtered optical signals to the fourth output port and a second predetermined portion of the amplified filtered optical signals to the fifth output port, the first and second predetermined portions of the amplified filtered optical signals being determined in dependence upon at least the second passband width;

f) a first photodetector optically comprising at least a second contact for reverse biasing the first photodetector, the first photodetector being coupled to the fourth output port of the second filter for receiving the first predetermined portion of the amplified filtered optical signals;

g) a second photodetector optically coupled to the fifth output port of the second filter for receiving the second predetermined portion of the amplified filtered optical signals; and

h) a third photodetector optically coupled to the second output port of the first filter for receiving a predetermined portion of optical signals propagating from the optical amplifier to the first filter, the predetermined portion of the optical signals determined in dependence upon at least the first passband width;

wherein,

the first contact and second contact are formed upon the same layer of the epitaxial semiconductor structure but are electrically isolated from one another.

2. A photonic component according to claim 1 wherein:

at least one of the first photodetector, the second photodetector, the third photodetector and the optical amplifier comprise a vertical element for coupling an optical signal within the predetermined second wavelength range of the one of the plurality of wavelength designated waveguides from the common designated waveguide to the one of the plurality of wavelength designated waveguides, the vertical element comprising at least one lateral taper formed by at least one semiconductor etching process within each of the common designated waveguide, the one of the plurality of wavelength designated waveguides, and any intermediate ones of the plurality of wavelength designated waveguides between the common designated waveguide and the one of the plurality of wavelength designated waveguides.

3. A photonic component according to claim 1 wherein,

at least one of the first filter and second filter comprise at least one of a thin-film filter and a waveguide filter implemented within the epitaxial semiconductor structure.

4. A photonic component according to claim 3 wherein,

when the at least one of is a thin-film filter it is at least one of abutting a facet of the epitaxial semiconductor structure, deposited upon a facet of the epitaxial semiconductor structure, and disposed within a feature formed within a surface of the epitaxial semiconductor structure.

5. A photonic component according to claim 3 wherein,

when the at least one of is a waveguide filter it comprises at least a first element selected from the group comprising, a multimode interference filter, a directional coupler, a Mach-Zehnder interferometer, an array waveguide grating, an echelle grating, a Bragg grating, and a ring resonator.

6. A photonic component according to claim 3 wherein,

when the at least one of is a waveguide filter a first predetermined portion of the waveguide filter is implemented within one of the common designated waveguide and another one of the plurality of wavelength designated waveguides, the one being adjacent to the one of the plurality of wavelength designated waveguides.

7. A photonic component comprising:

a) an epitaxial semiconductor structure grown in a III-V semiconductor material system grown in a single growth step upon a substrate comprising a common designated waveguide for supporting propagation of optical signals within a predetermined first wavelength range and at least one of a plurality of wavelength designated waveguides vertically disposed in order of increasing wavelength bandgap, each of the plurality of wavelength designated waveguides supporting a predetermined second wavelength range, each of the predetermined second wavelength ranges being within the predetermined first wavelength range;

b) an optical input port for receiving optical signals within the first wavelength range;

c) an optical amplifier comprising at least a gain section formed within the one of the plurality of wavelength designated waveguides, a first contact for forward biasing the optical amplifier, and a first output port, the optical amplifier optically coupled to the optical input port for receiving the optical signals and providing amplified optical signals to the first output port;

d) a first filter comprising at least a second output port and characterized by at least a first passband width, the filter optically coupled to the first output port of the optical amplifier and for providing a first predetermined portion of the amplified optical signals to the second output port, the first predetermined portion of the amplified optical signals being determined in dependence upon at least the first passband width;

e) a first photodetector optically comprising at least a second contact for reverse biasing the first photodetector, the first photodetector being coupled to the second output port of the first filter for receiving the first predetermined portion of the amplified optical signals;

wherein the first contact and second contact are formed upon the same layer of the epitaxial semiconductor structure but are electrically isolated from one another.

8. A photonic component according to claim 7 wherein,

at least one of the optical amplifier, the first filter, and the first photodetector further comprise a vertical element for coupling an optical signal within the predetermined second wavelength range of the one of the plurality of wavelength designated waveguides between at least one of from and to the common designated waveguide and at least one of to and from one of the plurality of wavelength designated waveguides, the vertical element comprising at least one lateral taper formed by at least one semiconductor etching process within each of the common designated waveguide, the one of the plurality of wavelength designated waveguides, and any intermediate ones of the plurality of wavelength designated waveguides between the common designated waveguide and the one of the plurality of wavelength designated waveguides.

9. A photonic component according to claim 7 further comprising;

f) a second photodetector optically connected to the first filter and for receiving a second predetermined portion of the amplified optical signals, the second predetermined portion of the amplified optical signals being determined in dependence upon at least the first passband width.

10. A photonic component according to claim 7 further comprising;

f) a second filter disposed between the input port and the optical amplifier and characterized by at least a second passband width, the filter for providing at least one of a third predetermined portion of the received optical signals to the optical amplifier and a first predetermined portion of noise generated by the optical amplifier to the input port, the at least one the third predetermined portion of the at least one of received optical signals and the first predetermined portion of the noise generated by the optical amplifier being determined in dependence upon at least the second passband width.

11. A photonic component according to claim 9 further comprising;

g) a third photodetector optically connected to the second filter and for receiving a second predetermined portion of the noise generated by the optical amplifier, the second predetermined portion of the noise generated by the optical amplifier being determined in dependence upon at least the second passband width.

12. A photonic component according to claim 7 wherein,

the first filter comprises at least one of a thin-film filter and a waveguide filter implemented within the epitaxial semiconductor structure.

13. A photonic component according to claim 10 wherein,

the second filter comprises at least one of a thin-film filter and a waveguide filter implemented within the epitaxial semiconductor structure.

14. A photonic component according to claim 12 wherein,

when the at least one of is a thin-film filter it is at least one of abutting a facet of the epitaxial semiconductor structure, deposited upon a facet of the epitaxial semiconductor structure, and disposed within a feature formed within a surface of the epitaxial semiconductor structure.

15. A photonic component according to claim 13 wherein,

when the at least one of is a thin-film filter it is at least one of abutting a facet of the epitaxial semiconductor structure, deposited upon a facet of the epitaxial semiconductor structure, and disposed within a feature formed within a surface of the epitaxial semiconductor structure.

16. A photonic component according to claim 12 wherein,

when the at least one of is a waveguide filter it comprises at least one of a first predetermined portion of the waveguide filter implemented within one of the common designated waveguide and another one of the plurality of wavelength designated waveguides, the one being adjacent to the one of the plurality of wavelength designated waveguides and at least a first element selected from the group comprising, a multimode interference filter, a directional coupler, a Mach-Zehnder interferometer, an array waveguide grating, an echelle grating, a Bragg grating, and a ring resonator.

17. A photonic component according to claim 13 wherein,

when the at least one of is a waveguide filter it comprises at least one of a first predetermined portion of the waveguide filter implemented within one of the common designated waveguide and another one of the plurality of wavelength designated waveguides, the one being adjacent to the one of the plurality of wavelength designated waveguides and at least a first element selected from the group comprising, a multimode interference filter, a directional coupler, a Mach-Zehnder interferometer, an array waveguide grating, an echelle grating, a Bragg grating, and a ring resonator.

18. A photonic component according to claim 7 further comprising;

f) at least one optical element of a plurality of optical elements disposed at least one of between the optical amplifier and first filter and between the first filter and first photodetector, the optical element comprising at least one of a waveguide filter element, a predetermined portion of a multimode interference waveguide element, a predetermined portion of a directional coupler, a predetermined portion of a Mach-Zehnder interferometer, a parabolic waveguide element, a planar waveguide, and a lens.

19. A photonic component according to claim 11 further comprising;

h) at least one optical element of a plurality of optical elements disposed at least one of between the optical amplifier and the second filter, between the input port and the second filter, and between the second filter and third photodetector, the optical element comprising at least one of a waveguide filter element, a predetermined portion of a multimode interference waveguide element, a predetermined portion of a directional coupler, a predetermined portion of a Mach-Zehnder interferometer, a parabolic waveguide element, a planar waveguide, and a lens.