Vertical cavity surface emitting laser

Abstract

To provide a vertical cavity surface emitting laser having a plurality of reflecting mirrors.SOLUTION: The vertical cavity surface emitting laser Z1 according to the present invention is provided with a plurality of reflectors. To be specific, the vertical cavity surface emitting laser Z1 of the present invention has a first resonance cavity C1 and a second resonance cavity C2, the second resonance cavity C2 is far away from the current limiting layer 13, and the light beam is mainly emitted after resonating in the second resonance cavity C2. With this structure, the influence of beam scattering caused by the current limiting layer 13 is solved, and the light emitting effect is improved.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vertical cavity surface emitting laser having multiple reflectors. [Background technology]

[0002] Conventional vertical cavity surface emitting lasers include a current limiting layer, which is typically made of oxide. When a beam resonates in the resonating chamber, the beam is often scattered by the current limiting layer, which affects the laser's light emission efficiency.

[0003] In the prior art, the above problem is solved by narrowing the limiting hole of the current limiting layer, which increases the electrical resistance of the laser, which is detrimental to the light emission of the laser device, or requires more electrical energy to emit light. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, how to improve the light-emitting efficiency of vertical cavity surface-emitting lasers by improving their structural design and overcome the above-mentioned defects has become one of the important problems that those skilled in the art are trying to solve. [Means for solving the problem]

[0005] The problem to be solved by the present invention is to provide a vertical cavity surface emitting laser including an active light emitting layer, a first reflector, a current limiting layer, a second reflector, and a third reflector.

[0006] In the vertical cavity surface emitting laser according to the present invention, opposing sides of the active light emitting layer are defined as a first side and a second side, respectively. A first reflecting mirror is located on the first side of the active light emitting layer and has a first reflecting surface. A current limiting layer is located on the second side of the active light emitting layer and has a limiting hole. A second reflecting mirror is located on the second side, and the current limiting layer is located between the second reflecting mirror and the active light emitting layer. Two opposing surfaces of the second reflecting mirror are defined as a transmitting surface and a second reflecting surface, respectively. The transmitting surface faces toward the current limiting layer, and the second reflecting surface is away from the current limiting layer. A first resonance chamber is formed between the second reflecting mirror and the first reflecting mirror. A third reflecting mirror is located on the second side, and the second reflecting mirror is located between the current limiting layer and the third reflecting mirror. The third reflecting mirror has a third reflecting surface and a light output surface facing each other, the third reflecting surface facing the second reflecting mirror, and a second resonant chamber is formed between the second reflecting mirror and the third reflecting mirror.

[0007] When a current is injected into the active light-emitting layer through the limiting hole, a first beam and a second beam are generated on the first and second sides of the active light-emitting layer, and the first beam is reflected by the first reflecting mirror to generate a first reflected beam. When the first reflected beam passes through the active light-emitting layer, the active light-emitting layer absorbs a portion of the first reflected beam and is further excited to generate the first beam and the second beam. The portion of the first reflected beam that passes through the active light-emitting layer is defined as the first transmitted beam. The second beam and the first transmitted beam that are reflected by the second reflecting mirror are defined as the second reflected beam. When the second reflected beam passes through the active light-emitting layer, the active light-emitting layer is again excited by the second reflected beam to generate the first beam and the second beam. Of the second beam and the first transmitted beam, the beam that passes through the second reflecting mirror and enters the second resonance chamber is defined as the second transmitted beam, and a laser beam is generated by the second transmitted beam resonating back and forth between the second reflecting mirror and the third reflecting mirror, and the laser beam is emitted from the light exit surface of the third reflecting mirror.

[0008] In the vertical cavity surface emitting laser according to the present invention, the current limiting layer is an oxide layer.

[0009] In the vertical cavity surface emitting laser according to the present invention, the first reflecting mirror, the second reflecting mirror and the third reflecting mirror are Bragg reflectors.

[0010] In the vertical cavity surface emitting laser according to the present invention, the reflectance of the first reflecting mirror is 99.9% or more.

[0011] In the vertical cavity surface emitting laser according to the present invention, the distance between the second reflecting mirror and the third reflecting mirror is greater than the distance between the first reflecting mirror and the second reflecting mirror. [Effects of the Invention]

[0012] In the vertical cavity surface emitting laser with multiple reflectors according to the present invention, a first resonant chamber and a second resonant chamber are formed by a first reflector, a second reflector, and a third reflector. This allows the beam to resonate mainly in the second resonant chamber, which is spaced apart from the current limiting layer. Therefore, in the vertical cavity surface emitting laser according to the present invention, the beam is relatively unaffected by the current limiting layer, and a laser beam can be generated and emitted after resonating in the second resonant chamber, thereby improving the light-emitting efficiency.

[0013] Furthermore, in the vertical cavity surface emitting laser according to the present invention, the thickness of the second reflecting mirror is designed so that the second transmitted beam in the second resonant chamber is reflected nearly 100% when it comes into contact with the second reflecting surface of the second reflecting mirror, which allows the transmitted beam to resonate so as to be concentrated within the second resonant chamber, and ultimately allows laser light to be emitted from the light output surface of the third reflecting mirror, which has a relatively low reflectivity. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing a state in which a vertical cavity surface emitting laser according to the present invention is used. DETAILED DESCRIPTION OF THE INVENTION

[0015] For a better understanding of the features and technical contents of the present invention, please refer to the detailed description and drawings of the vertical cavity surface emitting laser according to the present invention, however, the drawings are provided for reference and explanation only and do not limit the scope of the present invention.

[0016] The following describes the features of the vertical-cavity surface-emitting laser according to the present invention through more specific embodiments. Those skilled in the art can understand the advantages and effects of the vertical-cavity surface-emitting laser according to the present invention based on the disclosure of the present invention. The characteristic features described in the present specification can also be implemented or applied in other different specific embodiments. Various modifications and changes can be made to the details described in the present specification based on different perspectives and applications without departing from the concept of the present invention. The accompanying drawings are for simple schematic illustrations only and are not drawn to scale. The technical content of the vertical-cavity surface-emitting laser according to the present invention will be described in detail based on the following embodiments, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0017] In this specification, terms such as "first," "second," and "third" may be used to describe various elements or signals, but these elements or signals are not limited by these terms. These terms are mainly used to distinguish one element from another element or one signal from another signal. Furthermore, the term "or" used in this specification may include any one or a combination of multiple related listed items, depending on the actual situation.

[0018] Fig. 1 is a schematic diagram showing a state in which a vertical cavity surface emitting laser according to the present invention is used, in which the circuit board and metal electrodes are omitted. The vertical cavity surface emitting laser Z1 has multiple reflectors, specifically, an active light emitting layer 10, a first reflector 11, a current limiting layer 13, a second reflector 14, and a third reflector 12. Opposite sides of the active light emitting layer 10 are defined as a first side S1 and a second side S2, respectively. The first reflecting mirror 11 is located on a first side S1 of the active light-emitting layer 10. The first reflecting mirror 11 has a first reflecting surface 111. The current limiting layer 13 is located on the second side S2 of the active light-emitting layer 10, between the second reflector 14 and the active light-emitting layer 10. The current limiting layer 13 has a limiting hole 131. The second reflecting mirror 14 is located on the second side S2 between the current limiting layer 13 and the third reflecting mirror 12. Two opposing surfaces of the second reflecting mirror 14 are defined as a transmitting surface 141 and a second reflecting surface 142, respectively. The transmitting surface 141 faces the current limiting layer 13. The second reflecting surface 142 is away from the current limiting layer 13, and a first resonant chamber C1 is formed between the second reflecting mirror 14 and the first reflecting mirror 11. The third reflecting mirror 12 is located on the second side S2. The third reflecting mirror 12 has a third reflecting surface 121 and a light exit surface 122 that face each other. The third reflecting surface 121 faces the second reflecting mirror 14, and a second resonance chamber C2 is formed between the second reflecting mirror 14 and the third reflecting mirror 12.

[0019] When a current is injected into the active light-emitting layer 10 through the limiting hole 131, a first beam L1 and a second beam L2 are generated on the first side S1 and the second side S2 of the active light-emitting layer 10, respectively. After the first beam L1 is reflected by the first reflecting mirror 11, a first reflected beam L11 is generated. When the first reflected beam L11 passes through the active light-emitting layer 10, the active light-emitting layer 10 absorbs a portion of the first reflected beam L11 and is further excited by the first reflected beam L11 to generate the first beam L1 and the second beam L2. The portion of the first reflected beam L11 that is transmitted through the active light-emitting layer 10 is defined as a first transmitted beam L12. The second beam L2 and the portion of the first transmitted beam L12 that is reflected by the second reflecting mirror 14 are defined as a second reflected beam L21. When the second reflected beam L21 passes through the active light-emitting layer 10, the active light-emitting layer 10 is again excited by the second reflected beam L21 to generate the first beam L1 and the second beam L2. Of the second beam L2 and the first transmitted beam L12, the one that passes through the second reflecting mirror 14 and further enters the second resonance chamber C2 is defined as the second transmitted beam L22. When the second transmitted beam L22 resonates back and forth between the second reflecting mirror 14 and the third reflecting mirror 12, a laser beam L3 is generated. This laser beam L3 is emitted from the light-emitting surface 122 of the third reflecting mirror 12.

[0020] Here, the second reflected beam L21 is a part of the second beam L2 and the first transmitted beam L12 reflected by the second reflecting mirror 14. The active light-emitting layer 10 is excited by the second reflected beam L21 and generates the first beam L1 and the second beam L2 again. In this way, the first resonant chamber C1 contains the beams generated in succession.

[0021] On the other hand, the second transmitted beam L22 is the majority of the second beam L2 and the first transmitted beam L12 that has been transmitted through the second reflecting mirror 14. When this beam enters the second resonance chamber C2 and resonates back and forth, a laser beam L3 is generated and emitted from the light output surface 122.

[0022] In this embodiment, the second reflecting mirror 14 may be designed to have a different thickness. In this case, the second transmitted beam L22 in the second resonant chamber C2 can be reflected nearly 100% after reaching the second reflecting surface 142 of the second reflecting mirror 14, and the second transmitted beam L22 can be resonated back and forth within the second resonant chamber C2 to ultimately generate the laser beam L3.

[0023] The active light-emitting layer 10 includes multiple film layers (e.g., multiple undoped well layers and barrier layers that are alternately stacked) for forming multiple quantum wells. The materials of the well layers and barrier layers are determined depending on the wavelength of the beam to be generated. For example, if the beam to be generated is red light, the well layers and barrier layers are made of gallium arsenide and aluminum gallium arsenide (Al gallium arsenide), respectively. x Ga (1-x) When the beam to be generated is blue light, the barrier layer and well layer are preferably gallium nitride (GaN) layers and indium gallium nitride (InGaN) layers, respectively.

[0024] In this embodiment, the current limiting layer 13 may be an oxide layer.

[0025] In this embodiment, the first reflecting mirror 11, the second reflecting mirror 14, and the third reflecting mirror 12 may be Bragg reflectors. In other words, the first reflecting mirror 11, the third reflecting mirror 12, and the second reflecting mirror 14 may be Distributed Bragg Reflectors (DBRs) formed by alternately stacking two types of thin films with different refractive indexes, thereby allowing a beam having a predetermined wavelength to be reflected and resonated. In this embodiment, the reflectivity of the first reflecting mirror 11 is preferably 99.9% or higher.

[0026] In this embodiment, the second reflecting mirror 14 may be configured by stacking film layers containing multiple materials with different refractive indices. Furthermore, the number and thickness of the stacked layers may be adjusted according to the phase angle and interference requirements to obtain the required reflection effect.

[0027] In addition, in this embodiment, the distance H1 between the second reflecting mirror 14 and the third reflecting mirror 12 may be made larger than the distance H2 between the first reflecting mirror 11 and the second reflecting mirror 14 so that the vertical cavity surface emitting laser Z1 having multiple reflecting mirrors can output (emit, emit) purer laser light (stable mode).

[0028] It is worth noting that the proportion of the second beam L2 in the first beam L1 and the second beam L2 emitted when the active light-emitting layer 10 is excited by a current is greater than the proportion of the first beam L1. Also, under certain circumstances, the beam of the second beam L2 that passes through the second reflecting mirror 14 may be much larger than the beam that is reflected by the second reflecting mirror 14.

[0029] [Beneficial Effects of the Present Embodiment] In the vertical cavity surface emitting laser with multiple reflectors according to the present invention, a first resonant chamber and a second resonant chamber are formed by a first reflector, a second reflector, and a third reflector. This allows the beam to resonate mainly in the second resonant chamber, which is spaced apart from the current limiting layer. Therefore, in the vertical cavity surface emitting laser according to the present invention, the beam is relatively unaffected by the current limiting layer, and a laser beam can be generated and emitted after resonating in the second resonant chamber, thereby improving the light-emitting efficiency.

[0030] Furthermore, in the vertical cavity surface emitting laser according to the present invention, the thickness of the second reflecting mirror is designed so that the second transmitted beam in the second resonant chamber is reflected nearly 100% when it comes into contact with the second reflecting surface of the second reflecting mirror, which allows the transmitted beam to resonate so as to be concentrated within the second resonant chamber, and ultimately allows laser light to be emitted from the light output surface of the third reflecting mirror, which has a relatively low reflectivity.

[0031] The above disclosure is merely a preferred embodiment of the present invention, and does not limit the scope of the claims of the present invention. Therefore, all equivalent technical modifications made based on the contents of the specification and accompanying drawings of the present invention shall be included in the scope of the claims of the present invention. [Explanation of symbols]

[0032] Z1 Vertical Cavity Surface Emitting Laser 10 Active light-emitting layer 11 First reflector 111 First Reflecting Surface 12 Third reflector 121 Third Reflective Surface 122 Idemitsu surface 13 Current limiting layer 131 Restriction hole 14 Second reflector 141 Transparent surface 142 Second Reflective Surface C1 First resonating chamber C2 Second Resonating Chamber H1 distance H2 distance L1 First beam L11 First reflected beam L12 First transmitted beam L2 Second beam L21 Second reflected beam L22 Second transmitted beam L3 Laser Beam S1 First side S2 Second side

Claims

1. an active light-emitting layer, the opposing sides of which are defined as a first side and a second side; a first reflector located on the first side of the active light-emitting layer and having a first reflecting surface; a current limiting layer located on the second side of the active light emitting layer, the current limiting layer having a limiting hole; a second reflector located on the second side; a third reflector located on the second side; Including, the current limiting layer is located between the second reflecting mirror and the active light-emitting layer, two opposing surfaces of the second reflecting mirror are defined as a transmitting surface and a second reflecting surface, respectively, the transmitting surface faces the current limiting layer, and the second reflecting surface is away from the current limiting layer, and a first resonant chamber is formed between the second reflecting mirror and the first reflecting mirror; the second reflecting mirror is located between the current limiting layer and the third reflecting mirror, the third reflecting mirror has a third reflecting surface and a light output surface facing each other, the third reflecting surface faces the second reflecting mirror, and a second resonant chamber is formed between the second reflecting mirror and the third reflecting mirror; when a current is injected into the active light-emitting layer through the limiting hole, a first beam and a second beam are generated on the first side and the second side of the active light-emitting layer, respectively, the first beam is reflected by the first reflecting mirror and then a first reflected beam is generated, when the first reflected beam passes through the active light-emitting layer, the active light-emitting layer absorbs a part of the first reflected beam and is further excited to generate the first beam and the second beam, and a part of the first reflected beam that is transmitted through the active light-emitting layer is defined as a first transmitted beam; a beam of the second beam and the first transmitted beam reflected by the second reflecting mirror is defined as a second reflected beam, and when the second reflected beam passes through the active light-emitting layer, the active light-emitting layer is excited again by the second reflected beam to generate the first beam and the second beam; a second transmitted beam, which is one of the second beam and the first transmitted beam and which passes through the second reflecting mirror and enters the second resonance chamber; a laser beam is generated by the second transmitted beam resonating back and forth between the second reflecting mirror and the third reflecting mirror; and the laser beam is emitted from the light exit surface of the third reflecting mirror. A vertical cavity surface emitting laser characterized by:

2. the current limiting layer is an oxide layer; 2. The vertical cavity surface emitting laser according to claim 1.

3. the first reflecting mirror, the second reflecting mirror, and the third reflecting mirror are Bragg reflectors; 2. The vertical cavity surface emitting laser according to claim 1.

4. The reflectance of the first reflecting mirror is 99.9% or more.

2. The vertical cavity surface emitting laser according to claim 1.

5. the distance between the second reflecting mirror and the third reflecting mirror is greater than the distance between the first reflecting mirror and the second reflecting mirror; 2. The vertical cavity surface emitting laser according to claim 1.

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