Semiconductor light sources including selective diffusion for optical and electrical confinement

• US 8,774,246 B1
• Filed: 01/17/2012
• Issued: 07/08/2014
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Sdphotonics, LLC, University of Central Florida Research Foundation Inc. (State University System of Florida)
• Original Assignee: Sdphotonics, LLC, University of Central Florida Research Foundation Inc. (State University System of Florida)
• Inventors: Deppe, Dennis G., Freisem, Sabine M.
• Primary Examiner(s): Stultz, Jessica
• Assistant Examiner(s): CARTER, MICHAEL W
• Application Number:
  US13/352,050
• Time in Patent Office: 903 Days
• Field of Search: 372/45.01, 372/46.01, 372/46.015, 372/50.123, 372/50.124, 372/70
• US Class Current: 372/50.124
• CPC Class Codes: H01S 5/18327 Structure being part of a DBR H01S5/18391 takes precedence
• CPC Class Codes: H01S 5/18355 having a defined polarisation
• CPC Class Codes: H01S 5/18386 Details of the emission surface for influencing the near- or far-field, e.g. a grating on the surface
• CPC Class Codes: H01S 5/2059 by means of particular conductivity zones, e.g. obtained by particle bombardment or diffusion
• CPC Class Codes: H01S 5/3054 p-doping
• CPC Class Codes: H01S 5/4062 with an external cavity or using internal filters, e.g. Talbot filters
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

A semiconductor vertical resonant cavity light source includes an upper mirror and a lower minor that define a vertical resonant cavity. A first active region is within the vertical resonant cavity for light generation between the upper minor and lower mirror. The vertical resonant cavity includes an inner mode confinement region and an outer current blocking region. A depleted heterojunction current blocking region (DHCBR) is within the outer current blocking region of at least one of the upper minor, lower minor, and first active region. A conducting channel within the inner mode confinement region is framed by the DHCBR. The DHCBR forces current flow into the conducting channel during operation of the light source.

Claims

1. A semiconductor vertical resonant cavity light source, comprising:

an upper mirror and a lower mirror that define a vertical resonant cavity;

a first active region within said vertical resonant cavity for light generation between said upper mirror and said lower mirror;

said vertical resonant cavity including an inner mode confinement region and an outer current blocking region;

a depleted heterojunction current blocking region (DHCBR) within said outer current blocking region of at least one of said upper minor, said lower minor, and said first active region, and

a conducting channel within said inner mode confinement region that physically contacts and is framed by said DHCBR, wherein said DHCBR forces current flow into said conducting channel during operation of said vertical light source.

2. The vertical light source of claim 1, wherein said conducting channel comprises a selective p-type diffusion which converts an inner portion of said DHCBR to said conducting channel.

3. The vertical light source of claim 1, wherein said upper minor comprises a p-type distributed Bragg reflector (DBR) and said lower minor comprises an n-type DBR.

4. The vertical light source of claim 3, wherein at least one period of said p-type DBR or said n-type DBR includes a mesa in said conducting channel that is within two optical wavelengths distance to said first active region, said mesa being 5 Å

to 300 Å

in height.

5. The vertical light source of claim 4, wherein a packing density of said array of said vertical light sources exceeds two free space λ

'"'"'s for said vertical light sources.

6. The vertical light source of claim 1, wherein a more lightly doped side of said DHCBR has a maximum p-type concentration of 1×

10¹⁷ cm<sup>−

3</sup>, and wherein said conducting channel has a minimum p-type concentration of at least 1×

10¹⁷ cm<sup>−

3</sup>.

7. The vertical light source of claim 1, wherein a more lightly doped side of said DHCBR has a maximum p-type concentration of 1×

10¹⁶ cm<sup>−

3</sup>, and wherein said conducting channel has a minimum p-type concentration of at least 5×

10¹⁷ cm<sup>−

3</sup>.

8. The vertical light source of claim 1, wherein said vertical light source comprises a 2 dimensional array of said vertical light sources, further comprising a λ

spacer layer in said vertical resonant cavity sized to provide constructive feedback for phase coupling nearest neighbors of said array of said vertical light sources so that said 2 dimensional array of said vertical light sources collectively provide a single lobed angular radiation pattern.