Lattice-relaxed vertical optical cavities

• US 6,366,597 B1
• Filed: 08/16/1999
• Issued: 04/02/2002
• Est. Priority Date: 04/14/1998
• Status: Expired due to Term

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: Bandwidth9, Inc.
• Inventors: Yuen, Wupen, Li, Gabriel S., Chang-Hasnain, Contance J.
• Primary Examiner(s): Davie, James W.
• Application Number:
  US09/375,338
• Time in Patent Office: 960 Days
• Field of Search: 372/96, 372/45, 372/46
• US Class Current: 372/96
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01S 5/0614 controlled by electric field, i.e. whereby an additional electric field is used to tune the bandgap, e.g. using the Stark-effect
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18358 containing spacer layers to adjust the phase of the light wave in the cavity
• CPC Class Codes: H01S 5/18366 Membrane DBR, i.e. a movable DBR on top of the VCSEL
• CPC Class Codes: H01S 5/18372 by native oxidation
• CPC Class Codes: H01S 5/3095 Tunnel junction
• CPC Class Codes: H01S 5/3201 incorporating bulkstrain effects, e.g. strain compensation, strain related to polarisation
• CPC Class Codes: H01S 5/4018 Lasers electrically in series

Abstract

A monolithic long-wavelength vertical optical cavity device built up along a vertical direction. The device, when designed as a surface emitting laser, has a bottom Distributed Bragg Reflector (DBR), an active region consisting of active bulk medium or quantum wells, a current confinement layer next to the active layer, and a top DBR. The bottom DBR and the active region are lattice matched to the lattice defining material, while the top DBR is lattice relaxed. The design achieves high reflectivity, low absorption and diffraction loss. The design also ensures low production cost due to low precision requirement and wafer size production. The device can be used as a light detector when the active region is replaced by a spacer or a optical filter.

Claims

1. A vertical optical cavity, comprising:

a lattice-matched portion grown to match a lattice defining material, the lattice-matched portion including a bottom Distributed Bragg Reflector and a region coupled to the bottom Distributed Bragg Reflector; and

a lattice-relaxed portion having a lattice mismatch factor and including a top Distributed Bragg Reflector on the lattice-matched portion, wherein the top and bottom Distributed Bragg Reflectors are epitaxially grown.

2. The cavity of claim 1, wherein the region is positioned at a bottom portion of the bottom Distributed Bragg Reflector.

3. The cavity of claim 1, wherein the region is in an interior portion of the bottom Distributed Bragg Reflector.

4. The cavity of claim 1, wherein the region is an active region and the vertical optical cavity is a vertical cavity surface emitting laser.

5. The cavity of claim 4, wherein the active region is selected from the group consisting of a Quantum Well, a Quantum Wire, a Quantum dot and a bulk active media.

6. The cavity of claim 4, wherein the active region is a Quantum Well selected from the group consisting of compressive strained Quantum Wells, tensile strained Quantum Wells and unstrained Quantum Wells.

7. The cavity of claim 4, wherein the active region is a Quantum Well with a Quantum Well barrier selected from the group consisting of unstrained Quantum Well barriers and strained Quantum Well barriers.

8. The cavity of claim 1, wherein the region includes an active region which is reversibly biased such that the vertical optical cavity is a vertical cavity detector.

9. The cavity of claim 4, wherein the active region and the bottom Distributed Bragg Reflector are lattice matched.