Photonic crystal/waveguide coupler for VCSELS and photodetectors

• US 7,535,944 B1
• Filed: 06/03/2004
• Issued: 05/19/2009
• Est. Priority Date: 05/26/2000
• Status: Expired due to Fees

• Current Assignee: Oc Acquisition Corporation
• Original Assignee: OptiComp Corporation (Inneos, LLC)
• Inventors: Kim, Jongwoo, Loudeback, Duane A., Pickrell, Gregory, Guilfoyle, Peter
• Primary Examiner(s): Harvey; Minsun
• Assistant Examiner(s): Nguyen; Tuan N.
• Application Number:
  US10/860,607
• Time in Patent Office: 1,811 Days
• Field of Search: 372/43.01, 372/50.1, 359/344, 385/37
• US Class Current: 372/50.11
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: H01S 5/0422 with n- and p-contacts on the same side of the active layer
• CPC Class Codes: H01S 5/1032 Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region
• CPC Class Codes: H01S 5/11 Comprising a photonic bandgap structure
• 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 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/187 using Bragg reflection
• CPC Class Codes: H01S 5/2063 obtained by particle bombardment
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

An optical coupler comprises first and second mirrors. The first mirror is positioned with respect to the second mirror so that a resonant cavity is defined between them. A waveguide structure is positioned in the resonant cavity and includes a photonic crystal coupler. A thickness of the resonant cavity is selected so that a phase matching condition is satisfied for resonance in the resonant cavity. At least one of the first and second mirrors may be formed from a structure in an optoelectronic device. Alternatively, at least one of the first and second mirrors is formed from a semiconductor layer. At least one of the first and second mirrors may be formed as a semiconductor distributed bragg reflector, or as a dielectric distributed bragg reflector. At least one of the first and second mirrors may be a mirror in a vertical cavity surface emitting laser (VCSEL) structure. The photonic crystal coupler structure may be shaped so that first order modes of light incident upon the photonic crystal coupler structure are coupled into the waveguide while zero-order modes are reflected out into the resonant cavity and reflected by the mirror.

Claims

1. An optical coupler comprising:

first and second mirrors positioned in different planes, wherein the first mirror is positioned with respect to the second mirror so that a resonant cavity is defined between them;

a waveguide structure positioned in the resonant cavity and including a photonic crystal coupler structure, wherein the photonic crystal coupler structure is shaped so that first order modes of light incident upon the photonic crystal coupler structure are coupled into the waveguide while zero-order modes are reflected out into the resonant cavity and reflected by the mirror; and

wherein a thickness of the resonant cavity is selected so that a phase matching condition is satisfied for resonance in the resonant cavity.

2. An optical coupler comprising

a vertical cavity surface emitting laser diode (VCSEL) structure having a mirror and an output;

a mirror positioned opposite the output of the VCSEL structure and facing the mirror of the VCSEL;

wherein the mirror of the VCSEL and the mirror define a resonant cavity, and the photonic crystal coupler structure is shaped so that first order modes of light incident upon the photonic crystal coupler structure are coupled into the waveguide while zero-order modes are reflected out into the resonant cavity and reflected by the mirror; and

a waveguide structure having a photonic crystal coupler structure positioned between the VCSEL and the mirror.

3. An optical coupler comprising

a vertical cavity surface emitting laser diode (VCSEL) structure having a mirror and an output;

a mirror positioned opposite the output of the VCSEL structure and facing the mirror of the VCSEL; and

a waveguide structure having a photonic crystal coupler structure positioned between the VCSEL and the mirror;

wherein the photonic crystal coupler structure is shaped so that a portion of light which is incident normal to a surface of the photonic crystal coupler structure is coupled horizontally into the waveguide and a different portion of the normally incident light is reflected into a resonant cavity formed between the mirror of the VCSEL and the mirror and so that multiple reflections occur within the resonant cavity, and superposition occurs of the light coupled into the waveguide.

4. An optical coupler comprising a substrate;

a first mirror layer formed on the substrate;

a waveguide layer formed on the first mirror layer;

a photonic crystal coupler formed on the waveguide layer; and

a photodetector structure formed over the photonic crystal coupler, wherein the photodetector structure includes a second mirror layer which is positioned to reflect light from the photonic crystal coupler;

wherein the photonic crystal coupler formed on the waveguide layer is an etched photonic crystal coupler, and the photodetector structure formed over the photonic crystal coupler is an epitaxial regrowth photodetector structure.

5. An optical coupler comprising a substrate;

a first mirror layer formed on the substrate;

a waveguide layer formed on the first mirror layer;

a photonic crystal coupler formed on the waveguide layer; and

a photodetector structure formed over the photonic crystal coupler, wherein the photodetector structure includes a second mirror layer which is positioned to reflect light from the photonic crystal coupler;

wherein the photodetector structure formed over the photonic crystal coupler is a photodetector structure formed on a separate substrate, and further wherein, the photodetector structure is a photodetector structure wafer-bonded to the photonic crystal coupler.

6. An optical coupler comprising

a first substrate;

a first mirror layer formed on the first substrate;

a waveguide layer formed on the first mirror layer;

a photonic crystal coupler formed by etching the waveguide layer;

a second substrate;

a vertical cavity surface emitting laser diode structure formed on the second substrate, wherein the vertical cavity surface emitting laser diode structure includes a second mirror layer which is positioned to reflect light; and

wherein the vertical cavity surface emitting laser diode structure is wafer-fused onto the photonic crystal coupler structure so that light from the vertical cavity surface emitting laser diode structure is reflected into the photonic crystal coupler, so that air is enclosed in the photonic crystal coupler structure.

7. An optical coupler comprising

a first substrate;

a first mirror layer formed on the first substrate;

a waveguide layer formed on the first mirror layer;

a photonic crystal coupler formed by etching the waveguide layer;

a second substrate;

a photodetector structure formed on the second substrate, wherein the photodetector structure includes a second mirror layer which is positioned to reflect light; and

wherein the photodetector structure is wafer-fused onto the photonic crystal coupler structure so that light from the photonic crystal coupler is reflected into the photodetector structure, and so that air is enclosed in the photonic crystal coupler structure.

8. An optical coupler comprising

a substrate;

a first mirror layer formed on the substrate;

a waveguide layer formed on the first mirror layer;

a photonic crystal coupler formed on the waveguide layer;

a vertical cavity surface emitting laser diode structure formed on a portion of the photonic crystal coupler, wherein the vertical cavity surface emitting laser diode structure includes a second mirror layer which is positioned to reflect light from the photonic crystal coupler; and

a photodetector structure formed over a different portion of the photonic crystal coupler, wherein the photodetector structure includes a second mirror layer which is positioned to reflect light from the photonic crystal coupler.