High performance micromechanical tunable verticle cavity surface emitting laser

• US 5,771,253 A
• Filed: 01/29/1997
• Issued: 06/23/1998
• Est. Priority Date: 10/13/1995
• Status: Expired due to Term

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Vail, Edward C., Wu, Marianne S., Chang-Hasnain, Constance J.
• Primary Examiner(s): Bovernick, Rodney B.
• Assistant Examiner(s): Wise, Robert E.
• Application Number:
  US08/791,762
• Time in Patent Office: 510 Days
• Field of Search: 372/20, 372/32, 372/92, 372/96, 372/107
• US Class Current: 372/20
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: H01S 3/105 by controlling the mutual position or the reflecting properties of the reflectors of the cavity , e.g. by controlling the cavity lengthH01S3/10076, H01S3/13 take precedence
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/141 using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence
• CPC Class Codes: H01S 5/18366 Membrane DBR, i.e. a movable DBR on top of the VCSEL

Abstract

An electrostatically controlled cantilever apparatus for continuous tuning of the resonance wavelength of a Fabry-Perot cavity is disclosed. A resonant cavity is formed between two distributed Bragg reflector (DBR) mirrors each composed of multiple DBR layers. One such layer is replaced with a layer which has been fully oxidized except for a small aperture. This layer provides both optical and current confinement which allows for low threshold currents and high output power.

Claims

1. A cantilever apparatus for tuning the resonance wavelength of a Fabry-Perot cavity, said Fabry-Perot cavity comprising a bottom reflecting means and a top reflecting means, said cantilever apparatus comprising:

a) an electrically responsive substrate;

b) a support block positioned on said electrically responsive substrate;

c) a cantilever structure comprising a base section resting on said support block, a deformable section extending above said electrically responsive substrate and creating an air gap between said deformable section and said electrically responsive substrate, and an active head positioned at a predetermined location on said deformable section and comprising at least a portion of said top reflecting means;

d) an electrical tuning contact disposed on said cantilever structure for applying a tuning voltage V_t to produce a downward electrostatic force F_d between said electrical tuning contact and said electrically responsive substrate, thereby altering the size of said air gap and tuning said resonant wavelength;

e) an oxidation layer disposed within one of said reflecting means, said oxidation layer having been partially oxidized so that a small aperture of unoxidized area remains thereby providing optical and current confinement.

2. The apparatus of claim 1 wherein said oxidation layer occupies the bottom layer of said top reflecting means.

3. The apparatus of claim 1 wherein said reflecting means comprise multiple layers of distributed Bragg reflector (DBR) pairs, and said oxidation layer replaces one of said DBR layers.

4. The apparatus of claim 3 wherein said oxidation layer replaces the bottom DBR pair of said top reflecting means.

5. The apparatus of claim 3 or 4 wherein said oxidation layer is composed of AlAs.

6. A method for tuning a resonance wavelength of a Fabry-Perot cavity using a cantilever structure comprising a base section, a deformable section, and an active head, said Fabry-Perot cavity comprising a bottom reflecting means and a top reflecting means, said method comprising the steps of:

a) disposing an oxidation layer within one of said reflecting means;

b) partially oxidizing said layer such that a small aperture is left unoxidized thereby providing optical and current confinement;

c) positioning a support block on an electrically responsive substrate containing said Fabry-Perot cavity;

d) producing said cantilever structure on said support block such that said active head contains at least a portion of said top reflecting means and is positioned above said Fabry-Perot cavity, and said deformable section extends above said electrically responsive substrate and creates an air gap between said deformable section and said electrically responsive substrate;

e) disposing an electrical tuning contact on said cantilever structure;

f) applying a tuning voltage V_t to produce a vertical electrostatic force F_d between said electrical tuning contact and said electrically responsive substrate, thereby altering the size of said air gap and tuning said resonant wavelength.

7. The method of claim 6 wherein said oxidation layer is disposed at the bottom of the top reflective means.