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1. WO2020002028 - VCSEL ARRAY WITH SMALL PULSE DELAY

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

CLAIMS:

1. A Vertical Cavity Surface Emitting Laser (VCSEL) array (100) comprising at least two VCSEL sub-arrays, wherein each VCSEL sub-array comprises a multitude of VCSELs arranged on a substrate (110), wherein the at least two VCSEL sub-arrays are electrically contacted by means of a first electrical contact arrangement (105, 107) common to the VCSELs within the respective VCSEL sub-array, and a second electrical contact arrangement (150, 155), wherein the second electrical contact arrangement (150, 155) comprises a multitude of second electrical contacts (150), each second electrical contact (150) contacting a respective single VCSEL within the respective VCSEL sub-array individually, wherein each second electrical contact (150) comprises a second metal-semiconductor interface to a second semiconductor layer of an associated VCSEL of the multitude of VCSELs, wherein the second electrical contacts (150) are arranged to electrically pump the associated VCSEL along a current path to the first electrical contact arrangement (105, 107), wherein the current paths between the first electrical contact arrangement (105, 107) and the second electrical contacts (150) via the multitude of VCSELs are characterized by at least one symmetry selected out of the group of rotation symmetry, mirror symmetry and translation symmetry.

2. The VCSEL array (100) according to claim 1, wherein the substrate (110) of the at least two VCSEL sub-array is a common substrate (110), wherein the current paths between a first electrical contact arrangement (105, 107) of a first VCSEL sub-array and second electrical contacts (150) via the multitude of VCSELs of the first VCSEL sub-array and a second electrical contact arrangement (105, 107) of a second VCSEL sub-array and second electrical contacts (150) via the multitude of VCSELs of the second VCSEL sub array are characterized by at least one symmetry selected out of the group of rotation symmetry, mirror symmetry and translation symmetry.

3. The VCSEL array (100) according to anyone of the preceding claims, wherein the first electrical contact arrangement (105, 107) comprises at least one first electrical contact (107), wherein the at least one first electrical contact (107) comprises a first metal- semiconductor interface to a first semiconductor layer of the VCSEL array (100), and wherein the current paths are defined between the first metal- semiconductor interface and the second metal- semiconductor interface.

4. The VCSEL array (100) according to anyone of the preceding claims, wherein the first electrical contact arrangement (105, 107) and the second electrical contact arrangement (150, 155) are arranged on the same side of the substrate (110).

5. The VCSEL array (100) according to anyone of the preceding claims, wherein the current paths are arranged such that a length of a longest current path along the substrate (110) and the respective VCSEL is smaller than 4 times, preferably smaller than 2 times and most preferably smaller than 1.5 times a length of a shortest current path along the substrate (110) and the respective VCSEL.

6. The VCSEL array (100) according to anyone of the preceding claims, wherein the current paths are arranged such that a difference of the electrical impedance of the different current paths along the substrate (110) and the respective VCSELs is smaller than 50%, more preferably smaller than 20% and most preferably smaller than 10% of the smallest impedance of the current paths.

7. The VCSEL array (100) according to anyone of the preceding claims, wherein the current paths are arranged such that electrical impedances of the current paths along the respective VCSELs of the first VCSEL sub-array are the same as electrical impedances of the current path along the respective VCSEL of the second VCSEL subarray.

8. The VCSEL array according to anyone of claims 6 or 7, wherein the current paths are arranged such that the electrical impedance of the current paths along the respective VCSELs is the same.

9. The VCSEL array (100) according to anyone of the preceding claims, wherein the VCSELs are bottom emitters.

10. The VCSEL array (100) according to claim 9, wherein the VCSEL array (100) is characterized by a flip chip arrangement comprising a multitude of bumps (159), wherein the bumps (159) are arranged to mount the VCSEL array (100) on a carrier (180), wherein the bumps (159) are further arranged to provide an electrical connection to the first electrical contact arrangement (105, 107) and the second electrical contact arrangement (150, 155), and wherein the bumps (159) are arranged on a side of the substrate (110) opposite to a light emission side of the VCSEL array (100).

11. The VCSEL array (100) according to anyone of claims 9-10 comprising at least one optical structure (170), wherein the optical structure (170) is etched in a side of the substrate opposite to the side on which the VCSELs are arranged, wherein the optical structure (170) is arranged to transform laser light (10) emitted by the VCSEL array (100) during operation of the VCSEL array (100), wherein the optical structure (170) is

mechanically protected by a protection structure (190) comprising substrate material comprised by the substrate (110), wherein the protection structure (190) is arranged to avoid mechanical contact to the optical structure (170).

12. The VCSEL array (100) according to claim 11, wherein the protection structure (190) is aligned with the bumps (159) such that a bending of the substrate (110) between two bumps is reduced when a force perpendicular to a plane of the VCSEL array (100) is exerted to the protection structure (190).

13. A light emitting device comprising at least one VCSEL array (100) according to anyone of the preceding claims and an electrical driver (230) for providing an electrical drive current to the VCSELs.

14. A time-of-flight camera (200) comprising the light emitting device according to claim 13 or a VCSEL array (100) according to anyone of claims 1-12, the time-of-flight camera (200) further comprises a light detector (221) for detecting laser light (10) reflected by an object (300) and an evaluator, wherein the evaluator is arranged to determine a distance to the object (300) by means of the laser light (10) detected by the light detector (221).

15. A method of manufacturing a laser arrangement (100), the method comprising the steps of:

providing a Vertical Cavity Surface Emitting Laser (VCSEL) array (100) comprising at least two VCSEL sub-arrays, wherein each VCSEL sub-array comprises a multitude of VCSELs arranged on a substrate (110),

electrically contacting the at least two VCSEL sub-arrays by means of a first electrical contact arrangement (105, 107) common to the VCSELs within the respective VCSEL sub-array, and a second electrical contact arrangement (150, 155), wherein the second electrical contact arrangement (150, 155) comprises a multitude of second electrical contacts (150), each second electrical contact (150) contacting a respective single VCSEL within the respective VCSEL sub-array individually, wherein each second electrical contact (150) comprises a second metal- semiconductor interface to a second semiconductor layer of an associated VCSEL of the multitude of VCSELs, wherein the second electrical contacts (150) are arranged to electrically pump the associated VCSEL along a current path to the first electrical contact arrangement (105, 107),

wherein the first electrical contact arrangement (105, 107) and the second electrical contacts (150) are arranged such that the current paths between the first electrical contact arrangement (105, 107) and the second electrical contacts (150) via the multitude of VCSELs are characterized by at least one symmetry selected out of the group of rotation symmetry, mirror symmetry and translation symmetry.