Laser arrays for variable optical properties

• US 10,038,304 B2
• Filed: 07/29/2015
• Issued: 07/31/2018
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: TriLumina Corp
• Inventors: Joseph, John R.
• Primary Examiner(s): NGUYEN, TUAN N
• Application Number:
  US14/813,011
• Publication Number:
  US 20150340841A1
• Time in Patent Office: 1,098 Days
• Field of Search: 358 24, 372 5012, 372 501
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/0014 Measuring characteristics or properties thereof measuring techniques per se G01J, G01K, G01N, G01R
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/0234 Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/0237 by soldering
• CPC Class Codes: H01S 5/02469 Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06
• CPC Class Codes: H01S 5/04252 characterised by the material
• CPC Class Codes: H01S 5/04256 characterised by the configuration
• CPC Class Codes: H01S 5/04257 having positive and negative electrodes on the same side of the substrate
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18347 Mesa comprising active layer
• CPC Class Codes: H01S 5/18388 Lenses
• 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

A VCSEL array device formed of an array of raised VCSELs on an electrical contact and raised inactive regions connected to the electrical contact. The VCSELs can be physically and/or electrically organized to improve power or speed, or in phase and in parallel. The VCSELs and inactive regions are positioned between the electrical contact and an electrical waveguide. The VCSELs may be separated into subarrays and each VCSEL may be covered with an integrated or bonded microlens for directing beams of light without external lenses. The VCSELs may also be electrically selected to form two or more groups, with beams of light from each group have unique divergences, unique power or unique optical power, and each beam of light in a group forming a spot at a point on a line, on the same optical axis, or as part of a pattern.

Claims

1. An optical device, comprising:

a laser array including a plurality of vertical cavity surface emitting laser (VCSEL) devices arranged in a pattern on a first side of a substrate of the laser array; and

a plurality of microlenses integrally formed within a layer of a second side of the substrate opposite the first side of the substrate, wherein the layer is substantially transparent at a wavelength of light emitted by the VCSEL devices, wherein each microlens among the plurality of microlenses has a lens shape having a geometrical axis, wherein each microlens is located over a corresponding VCSEL device having an optical axis, wherein the geometrical axis of each microlens among at least some of the microlenses among the plurality of microlenses is aligned within the layer laterally offset from the optical axis of the corresponding VCSEL device, and wherein each microlens among the plurality of microlenses is configured to direct a beam of the light emitted by the corresponding VCSEL device through the layer to two or more targets or for non-mechanical beam scanning.

2. The optical device of claim 1, wherein first beams of light emitted by a first group of one or more VCSEL devices are focused on a first target among the two or more targets, and second beams of light emitted by a second group of one or more VCSEL devices are focused on a second target among the two or more targets, wherein each beam of light among the first beams of light has a first unique divergence and forms a first spot at a first point and each beam of light among the second beams of light has a second unique divergence and forms a second spot at a second point, and wherein the one or more VCSEL devices of the first group and the second group are configured to be electrically selected separately or in combination.

3. The optical device of claim 2, wherein the first group and the second group are driven by direct current.

4. The optical device of claim 2, wherein the first point and the second point are on a line.

5. The optical device of claim 2, wherein the first point and the second point form at least part of a unique pattern.

6. The optical device of claim 2, wherein the unique divergence is formed by one or more of properties of the one or more VCSEL devices, properties of the plurality of microlenses, or a combination thereof.

7. The optical device of claim 1, wherein first beams of light emitted by a first group of one or more VCSEL devices are focused on a first target among the two or more targets, and second beams of light emitted by a second group of one or more VCSEL devices are focused on a second target among the two or more targets, wherein each beam of light among the first beams of light has a first unique divergence and forms a first spot at a first point on an optical axis and each beam of light among the second beams of light has a second unique divergence and forms a second spot at a second point on the optical axis, and wherein the one or more VCSEL devices of the first group and the second group are configured to be electrically selected separately or in combination.

8. The optical device of claim 7, wherein the first group and the second group are driven by direct current.

9. The optical device of claim 1, wherein first beams of light emitted by a first group of one or more VCSEL devices are focused on a first target among the two or more targets, and second beams of light emitted by a second group of one or more VCSEL devices are focused on a second target among the two or more targets, wherein each beam of light among the first beams of light has a first unique power and forms a first spot at a first point on an optical axis and each beam of light among the second beams of light has second unique power and forms a second spot at a second point on the optical axis, and wherein the one or more VCSEL devices of the first group and the second group are configured to be electrically selected separately or in combination.

10. The optical device of claim 9, wherein the first group and the second group are driven by direct current.

11. The optical device of claim 1, wherein first beams of light emitted by a first group of one or more VCSEL devices are focused on a first target among the two or more targets, and second beams of light emitted by a second group of one or more VCSEL devices are focused on a second target among the two or more targets, wherein each beam of light among the first beams of light has a first unique optical power and forms a first spot at a first point on an optical axis and each beam of light among the second beams of light has second unique optical power and forms a second spot at a second point on the optical axis, and wherein the one or more VCSEL devices of the first group and the second group are configured to be electrically selected separately or in combination.

12. The optical device of claim 11, wherein the first group and the second group are driven by direct current.

13. A method for manufacturing an optical device, comprising:

building a laser array including a plurality of vertical cavity surface emitting laser (VCSEL) devices in a pattern on a first side of a substrate; and

building a plurality of microlenses integrally within a layer of a second side of the substrate opposite the first side, the layer being substantially transparent at a wavelength of light emitted by the VCSEL devices, each microlens among the plurality of microlenses having a lens shape with a geometrical axis and being built over a corresponding VCSEL device having an optical axis, with the geometrical axis of each microlens among at least some of the microlenses among the plurality of microlenses being aligned laterally offset within the layer from the optical axis of the corresponding VCSEL device.

14. The method as recited in claim 13, wherein each microlens is configured to direct a beam of light emitted by the corresponding VCSEL device to a target or for non-mechanical beam scanning.

15. The method as recited in claim 13, wherein building the plurality of microlenses includes defining each microlens with photoresist to form a shape and melting the shape before transferring the shapes to the layer through an etch.

16. The method as recited in claim 15, wherein the etch is a dry etch adjusted for or approaching an even etch selectivity between the layer and the photoresist.

17. The method as recite in claim 13, wherein building the plurality of microlenses includes gray scale lithography where a partially transmissive photomask is used to produce relief profiles in photoresist.

18. The method as recited in claim 13, wherein building the plurality of microlenses includes defining a surface profile for a polymer resist coating using direct write lithography.

19. The method as recited in claim 13, wherein building the plurality of microlenses includes depositing on the layer, above a location of the corresponding VCSEL device, a polymer material and curing the polymer material to form each microlens.

20. The method as recited in claim 13, wherein building a laser array is performed prior to building a plurality of microlenses.

21. The method as recited in claim 13, wherein building a plurality of microlenses is performed prior to building a laser array.