High power top emitting vertical cavity surface emitting laser

• US 20100035372A1
• Filed: 10/13/2009
• Published: 02/11/2010
• Est. Priority Date: 09/01/2003
• Status: Active Grant

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Avalon Photonics AG (Oclaro (North America), Inc.)
• Inventors: Gauggel, Hans-Peter, Royo, Paul
• Granted Patent: US 8,247,252 B2
• Time in Patent Office: Days
• US Class Current: 438/34
• 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 5/18344 characterized by the mesa, e.g. dimensions or shape of the mesa
• CPC Class Codes: H01S 5/2063 obtained by particle bombardment
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

A method of adjusting a power density in a laser device including a VCSEL array providing an increased power density at a high wall-plug efficiency in that the lateral design parameters are appropriately selected on the basis of a relationship that has been established for a specified vertical design, a corresponding process technology and specified operating conditions. Thus, the total output power, the power density, and the efficiency may be optimized independently from other design criteria and application requirements by tuning only the lateral size of the individual VCSEL elements and the pitch of nearest neighbors of the elements within the array. Hence, for a lateral size of less than 30 μm and a pitch of less than 80 μm, a highly efficient VCSEL array can be provided with a high power density, thereby optimizing manufacturing costs for the output power per chip area.

Claims

1. A method of adjusting a power density of a metal contact VCSEL array comprising the steps of:

establishing a relationship for a specified test array between an effective lateral size of a laser active region of VCSEL elements of a defined design, a pitch of nearest neighbors of the VCSEL elements when arranged according to the specified test array and a power output by the specified test array,

determining positions of VCSEL elements having the defined design within the VCSEL array on the basis of the relationship, and

manufacturing the VCSEL array with VCSEL elements of the defined design by forming the VCSEL elements substantially at the positions.

2. The method of claim 1, further comprising the step of:

determining a desired range for the power density based on a desired operating current range and a pitch of nearest neighbors determined by a selected manufacturing technology, wherein the desired range for the power density includes a maximum of the power density for the desired operating current range.

3. The method of claim 2, wherein:

the pitch of nearest neighbors determined by a selected manufacturing technology is a minimum pitch for the selected manufacturing technology.

4. The method of claim 1, further comprising:

determining a desired effective lateral size of the laser active region for said VCSEL elements so as to obtain a power density that lies within the desired range for the power density.

5. The method of claim 4, wherein:

said step of manufacturing the VCSEL array includes forming a current aperture having the desired effective lateral size by selectively oxidizing a material layer to obtain a conductive non-oxidized layer portion as the current aperture.

6. The method of claim 4, wherein:

said step of manufacturing the VCSEL array includes forming a current aperture having the desired effective lateral size by modifying a material layer stack by ion implantation so as to obtain a conductive non-modified layer portion as the current aperture.

7. The method of claim 1, further comprising:

determining data corresponding to a wall-plug efficiency of the specified test array for a plurality of different pitches and effective lateral sizes, and

determining the array positions based on the data.

8. The method of claim 7, wherein:

the data are derived from measurement results obtained from the specified test array.

9. The method of claim 1, further comprising:

estimating a heat distribution of the VCSEL array for predefined operating conditions and selecting the pitches and/or the effective lateral sizes on the basis of the heat distribution.

10. The method of claim 9, wherein:

the pitch for VCSEL elements to be positioned on an area of increased temperature is selected greater than for VCSEL elements located at an area of reduced temperature.

11. The method of claim 9, wherein:

the lateral size for VCSEL elements to be positioned on an area of increased temperature is selected greater than for VCSEL elements located at an area of reduced temperature.