Vertical cavity surface emitting laser

Patent metadata

Field	Value
Publication number	US-2018261979-A1
Application number	US-201615573846-A
Country	US
Kind code	A1
Filing date	May 31, 2016
Priority date	Jun 9, 2015
Publication date	Sep 13, 2018
Grant date	—

Abstract

The invention relates to a Vertical Cavity Surface Emitting Laser ( 100 ) comprising a first electrical contact ( 105 ), a substrate ( 110 ), a first Distributed Bragg Reflector ( 115 ), an active layer ( 120 ), a second Distributed Bragg Reflector ( 130 ) and a second electrical contact ( 135 ). The Vertical Cavity Surface Emitting Laser comprises at least one Al y Ga (1-y) As-layer with 0.95≤y≤1 with a thickness of at least 40 nm, wherein the Al y Ga (1-y) As-layer is separated by means of at least one oxidation control layer ( 119, 125 b ). The invention further relates to a laser device ( 300 ) comprising such a VCSEL ( 100 ) preferably an array of such a VCSELs ( 100 ) which are driven by an electrical driving circuit ( 310 ). The invention also relates to a method of manufacturing such a VCSEL ( 100 ).

First claim

1 . A Vertical Cavity Surface Emitting Laser comprising:
a first electrical contact; a substrate; a first Distributed Bragg Reflector; an active layer; a second Distributed Bragg Reflector; a second electrical contact; at least one Al y Ga (1-y) As-layer with 0.95≤y≤1, wherein the at least one Al y Ga (1-y) As-layer has a thickness of at least 40 nm, wherein the at least one Al y Ga (1-y) As-layer is separated into at least two sub-layers, wherein at least one oxidation control layer is disposed between the at least two sub-layers, wherein the at least one oxidation control layer has a thickness between 0.7 nm and 3 nm.

2 . The Vertical Cavity Surface Emitting Laser according to claim 1 , wherein the first Distributed Bragg Reflector or the second Distributed Bragg Reflector comprises the at least one Al y Ga (1-y) As-layer.

3 . The Vertical Cavity Surface Emitting Laser according to claim 1 further comprising a current aperture layer, wherein the current aperture layer comprises the at least one Al y Ga (1-y) As-layer.

4 . The Vertical Cavity Surface Emitting Laser according to claim 1 , further comprising at least two current aperture layers arranged below or above the active layer,
wherein each of the current aperture layers comprises a Al y Ga (1-y) As-layer, wherein a first current aperture layer of the at least two current layers has a first current aperture, wherein a second current aperture layer of the at least two current layers has a second current aperture, wherein the first current aperture layer of the at least two current aperture layers is arranged nearer to the active layer than the second current aperture layer, wherein the first current aperture is larger than the second current aperture.

5 . The Vertical Cavity Surface Emitting Laser according to claim 1 , wherein a material of the oxidation control layer comprises Al x Ga (1-x) As, wherein 0≤x≤0.9.

6 . The Vertical Cavity Surface Emitting Laser according to claim 1 ,
wherein y>0.99, wherein the at least two sub-layers are separated by at least two oxidation control layers, wherein a material of the at least one of the two oxidation control layers comprises Al x Ga (1-x) As with 0.4≤x≤0.6.

7 . The Vertical Cavity Surface Emitting Laser according to claim 1 , wherein a thickness of the at least one oxidation control layer comprises between 3% and 10% of a total thickness of the Al y Ga (1-y) As-layer.

8 . The Vertical Cavity Surface Emitting Laser according to claim 1 , wherein at least one of the at least one Al y Ga (1-y) As-layers comprises a tapered oxidation profile.

9 . The Vertical Cavity Surface Emitting Laser according to claim 8 ,
wherein the at least one Al y Ga (1-y) As-layer with the tapered oxidation profile comprises at least two oxidation control layers, wherein the at least two oxidation control layers separate the at least one Al y Ga (1-y) As-layer in at least three sub-layers, wherein at least one of the three sub-layers has a different thickness as the other sub-layers.

10 . The Vertical Cavity Surface Emitting Laser according to claim 8 , wherein a waistline of the tapered oxidation profile is arranged in a range of a node of a standing wave pattern of the Vertical Cavity Surface Emitting Laser when driven at a predefined electrical driving current.

11 . The Vertical Cavity Surface Emitting Laser according to claim 1 ,
wherein the first and the second Distributed Bragg Reflector comprise a multitude of high refractive index layers and a multitude of low refractive index layers, wherein the low refractive index layers comprise said Al y Ga (1-y) As-layers.

12 . A laser device comprising at least one Vertical Cavity Surface Emitting Laser according to claim 1 and an electrical driving circuit for electrically driving the Vertical Cavity Surface Emitting Laser.

13 . A method of fabricating a Vertical Cavity Surface Emitting Laser, the method comprising:
providing a first electrical contact; providing a substrate; providing a first distributed Bragg reflector; providing an active layer; providing a second distributed Bragg reflector; providing a second electrical contact; providing at least one Al y Ga (1-y) As-layer with 0.95≤y≤1, wherein the at least one Al y Ga (1-y) As-layer has a thickness of at least 40 nm, wherein the at least one Al y Ga (1-y) As-layer is separated into at least two sub-layers, wherein at least one oxidation control layer, wherein the at least one oxidation control layer is disposed between the at least two sub-layers, wherein the at least on oxidation layer has a thickness between 0.7 nm and 3 nm.

Assignees

• Koninklijke Philips Nv

Inventors

• Gerlach Philipp Henning
• King Roger

Classifications

• H01S5/18333

  only above the active layer · CPC title

• H01S5/423

  having a vertical cavity · CPC title

• H01S5/18313 Primary

  by oxidizing at least one of the DBR layers · CPC title

• H01S2301/173

  The laser chip comprising special buffer layers, e.g. dislocation prevention or reduction · CPC title

• H01S5/18305 Primary

  with emission through the substrate, i.e. bottom emission · CPC title