CN-122000787-A - Vertical cavity surface emitting laser with grating structure

Abstract

The application provides a vertical cavity surface emitting laser with a grating structure, which comprises a circuit substrate, a luminous composite layer and the grating structure. The light-emitting composite layer is positioned on the circuit substrate and comprises a first Bragg reflector, a light-emitting layer and a second Bragg reflector. The grating structure is positioned on the first Bragg reflector and comprises a contact layer and a protective layer. The contact layer comprises a body and a plurality of convex parts, the convex parts are positioned on the body, and a groove is formed between two adjacent convex parts. The protective layer is positioned on the contact layer and covers each convex part and each groove, and the protective layer is provided with a surface with high and low fluctuation corresponding to the structures of each convex part and each groove.

Inventors

• Pan Baizhou
• ZHENG WEIWEN

Assignees

• 华立捷科技股份有限公司

Dates

Publication Date

20260508

Application Date

20241101

Claims (10)

1. 1. A vertical cavity surface emitting laser having a grating structure, the vertical cavity surface emitting laser having a grating structure comprising: a circuit substrate; The light-emitting composite layer is positioned on the circuit substrate and comprises a first Bragg reflector, a light-emitting layer and a second Bragg reflector, wherein the first Bragg reflector and the second Bragg reflector are respectively positioned on two sides of the light-emitting layer; The contact layer is positioned on the first Bragg reflector and is provided with a grating structure, the grating structure comprises a body and a plurality of convex parts, the convex parts are positioned on the body, and a groove is formed between two adjacent convex parts; An electrode layer on the contact layer, the electrode layer having a light exit hole, at least a part of the grating structure exposed to the light exit hole, and And the protective layer covers the electrode layer and the grating structure, corresponds to the shapes of each convex part and each groove, and has a surface with high and low fluctuation.
2. 2. The grating structured vertical cavity surface emitting laser of claim 1, wherein the protective layer is an aluminum oxide layer, a silicon dioxide layer, a silicon nitride layer, or a magnesium fluoride layer.
3. 3. The grating structured vertical cavity surface emitting laser of claim 1, wherein a distance between centers of two adjacent ones of the convex portions is smaller than a wavelength at which the light emitting composite layer emits light.
4. 4. The vertical cavity surface emitting laser with grating structure according to claim 1, wherein the depth of the groove in a vertical direction is 10nm or more and 2 times or less the wavelength of the light emitted by the light emitting composite layer.
5. 5. The grating structured vertical cavity surface emitting laser of claim 1, wherein the contact layer has a thickness in a vertical direction of 10nm to 10um.
6. 6. The vertical cavity surface emitting laser with grating structure according to claim 1, wherein the thickness of the protective layer in a vertical direction is 1nm or more and 0.4 times or less of a distance between two adjacent convex portions.
7. 7. The grating structured vertical cavity surface emitting laser according to claim 1, wherein a ratio of a width of the groove to a distance between centers of two adjacent protrusions in a horizontal direction is 0.1-0.9.
8. 8. The vertical cavity surface emitting laser according to claim 1, wherein the plurality of protrusions and the plurality of recesses extend in a first direction in a top view, the light exit hole defines a center line passing through a center point of the light exit hole, the center line is parallel to a second direction, the second direction is orthogonal to the first direction, the center line divides the grating structure exposed in the light exit hole into a first portion and a second portion, and the first portion and the second portion are not line-symmetrical with respect to the center line.
9. 9. The grating structured vertical cavity surface emitting laser according to claim 8, wherein a projected area ratio of the first portion to the second portion projected along a light emitting direction is 10% or more.
10. 10. The grating structured vertical cavity surface emitting laser of claim 1, wherein the first bragg mirror is a P-type bragg mirror or an N-type bragg mirror.

Description

Vertical cavity surface emitting laser with grating structure Technical Field The present application relates to a vertical cavity surface emitting laser, and more particularly, to a vertical cavity surface emitting laser having a grating structure. Background The semiconductor laser has the advantages of small volume, light weight, low cost, high energy conversion efficiency and the like, and is widely applied to electronic products. In the prior art, semiconductor lasers develop vertical resonant cavity surface emitting lasers (VCSELs) and are applied to various fields, including the technical fields of optical fiber communication systems, consumer electronic scanning systems (such as iris recognition of smart phones and tablet computers), 3D printing, biological recognition sensing, laser projection display and the like. It is known that the future demand for vertical cavity surface emitting lasers is considerable. Therefore, how to provide a vertical cavity surface emitting laser with stable structure and good performance has become one of the important issues to be solved by the industry. Disclosure of Invention The application aims to provide a vertical cavity surface emitting laser with a grating structure, which comprises a circuit substrate, a light emitting composite layer, a contact layer and a protective layer. The light-emitting composite layer is positioned on the circuit substrate and comprises a first Bragg reflector, a light-emitting layer and a second Bragg reflector, wherein the first Bragg reflector and the second Bragg reflector are respectively positioned on two sides of the light-emitting layer. The contact layer is positioned on the first Bragg reflector, the contact layer is provided with a grating structure, the grating structure comprises a body and a plurality of convex parts, the convex parts are positioned on the body, and a groove is formed between two adjacent convex parts. The electrode layer is positioned on the contact layer, the electrode layer is provided with a light outlet, and at least one part of the grating structure is exposed in the light outlet. The protective layer covers the electrode layer and the grating structure, the protective layer corresponds to the shape of each convex part and each groove, and the protective layer has a surface with high and low fluctuation. According to a possible embodiment, the protective layer is an aluminum oxide layer, a silicon dioxide layer, a silicon nitride layer or a magnesium fluoride layer. According to a possible embodiment, the distance between the centers of two adjacent protrusions is smaller than the wavelength of the light emitted by the light emitting composite layer. According to a possible embodiment, the depth of the groove in the vertical direction is more than 10nm and less than or equal to 2 times the wavelength of the light emitted by the light emitting composite layer. According to a possible embodiment, the thickness of the contact layer in the vertical direction is 10nm to 10um. According to a possible embodiment, the thickness of the protective layer in the vertical direction is 1nm or more and is less than or equal to 0.4 times the distance between two adjacent protrusions. According to a possible embodiment, the ratio of the width of the recess to the distance between the centers of two adjacent protrusions in the horizontal direction is 0.1-0.9. According to one possible embodiment, the plurality of protrusions and the plurality of recesses extend along a first direction in a top view, the light exit hole defines a center line passing through a center point of the light exit hole, the center line is parallel to a second direction, the second direction is orthogonal to the first direction, the center line divides the grating structure exposed in the light exit hole into a first portion and a second portion, and the first portion and the second portion are not symmetric with respect to the center line. According to a possible embodiment, the ratio of the projection areas of the first portion and the second portion projected along a light emitting direction is greater than or equal to 10%. According to a possible embodiment, the first Bragg mirror is a P-type Bragg mirror or an N-type Bragg mirror. The vertical cavity surface emitting laser with the grating structure has the beneficial effects that the grating structure can be provided by the technical scheme that the contact layer is provided with the grating structure, the grating structure comprises a body and a plurality of convex parts, the convex parts are positioned on the body, grooves and electrode layers are formed between the two adjacent convex parts, the electrode layers are provided with light emitting holes, at least one part of the grating structure is exposed out of the light emitting holes, the electrode layers and the grating structure are covered by the protective layer, the protective layer corresponds to the shape of each convex part