CN109921284B - Asymmetric microdisk cavity edge emitting semiconductor laser array - Google Patents

Abstract

An asymmetric microdisk cavity edge-emitting semiconductor laser array belongs to the technical field of semiconductor lasers. The existing semiconductor laser linear array faces multiple technical problems on beam shaping and output coupling. In the invention, a single laser tube forming a laser array is an asymmetric microdisk cavity edge emitting semiconductor laser; the laser array structure comprises a front row of laser lines and a rear row of laser lines, wherein the front row of laser lines and the rear row of laser lines are positioned on the same substrate, 3-4 laser single tubes are arranged in a line at the same geometric center distance in the front row of laser lines, 2-4 laser single tubes are arranged in a line at the same geometric center distance in the rear row of laser lines, and the geometric center distance of the laser single tubes in the front row of laser lines is the same as that of each laser single tube in the rear row of laser lines; the light emitting directions of the laser single tubes are the same and face the front, and the distance between the light emitting axes of the laser single tubes in the rear row of laser linear arrays and the geometric center of the laser single tube closest to the laser single tube in the front row of laser linear arrays is half of the geometric center distance.

Description

Asymmetric Microdisk Cavity Edge-Emitting Semiconductor Laser Array

technical field

The invention relates to an asymmetric micro-disk cavity edge-emitting semiconductor laser array, which utilizes spiral, elliptical and helical asymmetric micro-disk cavities to form an array in the form of interstitial arrangement, greatly improving the output optical power of a semiconductor laser light source, and belongs to semiconductor The field of laser technology.

Background technique

Microdisk cavity edge-emitting semiconductor lasers have the characteristics of low threshold, small size, simple geometry, dynamic mode operation, and easy integration with other electronic components. However, it cannot meet the output optical power requirements of semiconductor laser light sources in the fields of all-optical networks and optoelectronic information, because the output optical power of microdisk cavity edge-emitting semiconductor lasers is lower than that of ordinary semiconductor lasers. Increasing the size of the laser to expand the gain region in the cavity will not increase the output optical power.

Compared with the circular microdisk cavity edge-emitting semiconductor laser, the asymmetric microdisk cavity edge-emitting semiconductor laser has a strong light output direction and high light output efficiency, so the existing technology arranges a plurality of asymmetric microdisk cavity edge-emitting semiconductor lasers in a line. , so as to improve the output optical power of the semiconductor laser light source. For example, the single tube of the limacon-shaped micro-cavity laser is arranged in a 1×3 line. The light-emitting direction of the emitting semiconductor laser is parallel to the epitaxial wafer. If it is arranged in an array, the light-emitting direction is required to be consistent, and the single-tube laser in the front row is bound to block the light output of the single-tube laser in the rear row. As far as the line is concerned, due to the limitation of the heat sink side length, too many single tubes cannot be arranged, for example, 1×4 will reach the limit.

In the prior art, a plurality of laser line arrays are stacked to form a laser line array array. In the laser line array array, each single laser tube is distributed in a façade, which is equivalent to a façade array, and outputs light. Power has been greatly improved. However, this solution is difficult to ensure the consistent light output direction of each laser tube constituting the laser array in the process of stacking multiple laser lines, and the heat dissipation problem of this laser line array is more prominent; Follow-up links such as output coupling face multiple technical difficulties.

SUMMARY OF THE INVENTION

The purpose of the present invention is to further improve the output optical power of the edge-emitting semiconductor laser light source in the form of a planar array, and at the same time to ensure that the light-emitting directions of the laser array devices are consistent and concentrated. We have invented an asymmetric microdisk cavity edge-emitting semiconductor laser array. , In the laser array, the single laser tubes in the front and rear rows are distributed in a plane, and the light-emitting directions are the same, and the front row does not constitute a shield for the rear row.

In the asymmetric microdisk cavity edge emitting semiconductor laser array of the present invention, the single laser tube constituting the laser array is an asymmetric microdisk cavity edge emitting semiconductor laser; it is characterized in that the front row of laser lines and the rear row of laser lines are located on the same substrate On the bottom, in the front row of laser lines, 3 to 4 single laser tubes are arranged in line with the same geometric center distance, and in the rear row of laser lines, 2 to 4 single laser tubes are arranged in line with the same geometric center distance , the geometric center distance of the single laser tubes in the front row of laser lines is the same as the geometric center distance of each laser single tube in the rear row of laser lines; the light output directions of the single laser tubes are the same and facing forward, and the laser lines in the rear row The optical axis of the outgoing light of the single laser tube is separated from the geometric center of the nearest laser single tube in the front row of laser lines by one-half of the geometric center distance.

The technical effect of the present invention is that, compared with the existing asymmetric microdisk cavity edge-emitting semiconductor laser line array, the number of single tubes of the laser array of the present invention can be doubled, and the output optical power can be doubled accordingly, which can be fully The fields of optical networking and optoelectronic information provide quasi-continuous semiconductor laser light sources with low threshold kilowatts and above. In addition, since each single tube constituting the laser array is fabricated on the same substrate, that is to say, each light-emitting point in the laser array is located in a plane, the light-emitting direction is the same, and the optical axis of the emitted light is parallel. The single laser tubes in the laser line are arranged staggered, that is, the single tubes in the rear row and the single tubes in the front row are arranged in an empty space, so that all the single tubes are arranged more compactly. Therefore, the laser array of the present invention can achieve the same light output direction, Concentration, on this basis, the subsequent beam shaping, multi-beam clustering, and output coupling will be easier.

Compared with the existing laser line array stacking array, the present invention belongs to a plane array, and the laser array substrate as a whole is in contact with the heat sink when the device is packaged, and the heat dissipation is good.

Description of drawings

FIG. 1 is a schematic top view of the structure of the edge-emitting semiconductor laser array using spiral microdisk cavities arranged in the first three and the second manner according to the present invention, and this figure is also used as an abstract drawing. FIG. 2 is a schematic top view of the structure of the edge-emitting semiconductor laser array according to the present invention, which adopts spiral micro-disk cavities arranged in the front four and the back four. FIG. 3 is a schematic top view of the structure of the edge-emitting semiconductor laser array using elliptical microdisk cavities arranged in the first three and the second manner according to the present invention. FIG. 4 is a schematic top view of the structure of the edge-emitting semiconductor laser array arranged in the form of three fronts and two backs by adopting the spiral microdisk cavity according to the present invention.

Detailed ways

In the asymmetric microdisk cavity edge emitting semiconductor laser array of the present invention, the laser single tube 1 constituting the laser array is an asymmetric microdisk cavity edge emitting semiconductor laser; the asymmetric microdisk cavity is a spiral microdisk cavity, an elliptical microdisk cavity or The spiral-shaped microdisk cavity is shown in Figures 1 to 4.

The front row of laser lines and the rear row of laser lines are located on the same substrate 2 . In the front row of laser lines, 3 to 4 single laser tubes 1 are arranged in line with the same geometric center distance, and in the rear row of laser lines, 2 to 4 single laser tubes 1 are arranged in line with the same geometric center distance. For example, in the front row of laser lines, 3 single laser tubes 1 are arranged in line with the same geometric center distance; Three after two arrays, as shown in Figure 1, Figure 3, and Figure 4. For another example, in the front row of laser lines, 4 single laser tubes 1 are arranged in the same geometric center distance, and in the rear row of laser lines, 4 laser single tubes 1 are arranged in the same geometric center distance, such as shown in Figure 2. The geometric center distance of the single laser tubes in the front row of laser lines is the same as the geometric center distance of each laser single tube in the rear row of laser lines. The light-emitting direction of each laser single tube 1 is the same and faces forward, and the optical axis of the emitted light of the laser single tube 1 in the rear row of laser lines is 1/2 away from the geometric center of the nearest laser single tube 1 in the front row of laser lines. A geometric center distance.

The light-emitting point of the single laser tube 1 in the rear row of laser lines is located at the vertex angle ∠A of the isosceles triangle ΔABC, and the two laser tubes in the front row of laser lines closest to the single laser tube 1 in the rear row of laser lines are located at the apex angle ∠A of the isosceles triangle ΔABC. The geometric centers of the single laser tubes 1 are respectively located at the base angles ∠B and ∠C of the isosceles triangle ΔABC, as shown in Figures 1 to 4; ∠A=60°～120°; when the asymmetric microdisk When the cavity is a snail-shaped microdisc cavity, the waist length of the isosceles triangle ΔABC is AB=AC=500～650 μm, and when the asymmetric microdisc cavity is an oval microdisc cavity, the waist length of the isosceles triangle ΔABC is AB=AC=350～ 500 μm, when the asymmetric microdisk cavity is a spiral microdisk cavity, the waist length of the isosceles triangle ΔABC is AB=AC=800-1000 μm. Determining the mutual positional relationship of the single laser tubes constituting the laser array of the present invention in this way can avoid the occurrence of light from the single laser tubes located in the rear row of laser lines and the microdisk cavity of the single laser tubes located in the front row of laser lines. Obvious thermal superposition phenomenon to ensure stable light output of the laser array and prolong the life of the laser array device. The operating temperature of the laser array device is kept within the normal range, which can ensure the luminous efficiency of the laser. Determining the mutual positional relationship of the single laser tubes constituting the laser array of the present invention in this way can also ensure the light emitting point density in the laser array, and improve the optical power density of the laser while making the device structure compact.

Example 1

The number of single laser tubes of the front-row laser line and the rear-row laser line is 4. As shown in Figure 2, the asymmetric microdisk cavity is a snail-shaped microdisk cavity, and the snail polar coordinate equation of the snail-shaped microdisk cavity is ρ( θ)=ρ ₀ (1+εcosθ), where ρ(θ) is the polar diameter, ρ ₀ is the characteristic radius, θ is the polar angle, ε is the deformation factor, and ρ ₀ is the characteristic radius of the spiral microdisk cavity, taking ρ ₀ =150 μm, ε=0.42. The distances AB and AC between the light-emitting point A of the single laser tube in the rear row of laser lines and the geometric centers B and C of the two closest laser single tubes in the front row of laser lines are equal, and the angle between AB and AC is ∠ A=120°, AB=AC=500μm, from this, it can be calculated that the geometric center distance of two adjacent laser single tubes in the front row of laser lines is about 850μm, which offsets the characteristic radius of the two snail-shaped microdisk cavity cavity, The cavity surfaces corresponding to the two snail-shaped microdisk cavities are about 550 μm apart. According to the beam far-field energy distribution diagram of the edge-emitting semiconductor laser of the spiral-shaped microdisk cavity obtained by the experimental measurement, it can be seen that the horizontal divergence angle of the emitted light from the spiral-shaped microdisk cavity is 35°, from which the single laser tube in the rear row of laser lines can be calculated. When the outgoing light passes through the middle of two adjacent laser single tubes in the front row of laser lines, the beam diverges to less than 300 μm in the horizontal direction, so there will be no thermal superposition phenomenon. The laser array was installed on the heat sink 3 to simulate the heat field of the heat sink, and no obvious thermal superposition phenomenon was found.

Example 2

The number of single laser tubes in the front row of laser lines is 3, and the number of single laser tubes in the rear row of laser lines is 2. As shown in Figure 3, the asymmetric microdisk cavity is an elliptical microdisk cavity, and the ellipse deformation factor ε is defined as The ratio of the major axis to the minor axis of the ellipse is taken as the deformation factor ε=1.2, and the length of the minor axis is 120 μm. The distances AB and AC between the light-emitting point A of the single laser tube in the rear row of laser lines and the geometric centers B and C of the two closest laser single tubes in the front row of laser lines are equal, and the angle between AB and AC is ∠ A=60°, AB=AC=500μm, from this, it can be calculated that the geometric center distance of two adjacent laser single tubes in the front row of laser lines is about 500μm, which offsets the lateral radius of the two elliptical microdisk cavity cavities, The lateral radius of the cavity is also the length of the semi-major axis of the ellipse, and the cavity surfaces corresponding to the two elliptical microdisk cavities are about 200 μm apart. According to the beam far-field energy distribution diagram of the edge-emitting semiconductor laser of the elliptical microdisk cavity measured experimentally, it can be seen that the horizontal divergence angle of the emitted light from the elliptical microdisk cavity is 10°, and thus the single laser tube in the rear row of laser lines can be calculated When the outgoing light passes through the middle of two adjacent laser single tubes in the front row of laser lines, the beam diverges to less than 100 μm in the horizontal direction, so there will be no thermal superposition phenomenon. The laser array was installed on the heat sink 3 to simulate the heat field of the heat sink, and no obvious thermal superposition phenomenon was found.

Example 3

其中ρ(θ)为极径，ρ₀为特征半径，θ为极角，ε为形变因子，将ρ₀作为螺旋形微盘腔腔体特征半径，取ρ₀＝200μm，ε＝0.1。后排激光器线列中的激光器单管的出光点A与前排激光器线列中两个最接近的激光器单管的几何中心B、C的距离AB、AC相等，AB与AC的夹角即∠A＝90°，AB＝AC＝900μm，由此可计算出前排激光器线列中的两个相邻激光器单管的几何中心距约为1270μm，抵减两个螺旋形微盘腔腔体特征半径，该两个螺旋形微盘腔对应的腔面相距约870μm。根据实验测量所得螺旋形微盘腔边发射半导体激光器的光束远场能量分布图，可知螺旋形微盘腔出射光的水平发散角为40°，由此可计算出后排激光器线列中的激光器单管的出射光从前排激光器线列中的两个相邻激光器单管中间经过时，光束在水平方向上发散到接近550μm，因此，不会出现热叠加现象。将该激光器阵列安装于热沉3之上，模拟热沉热场，未发现明显的热叠加现象。The number of single laser tubes in the front row of laser lines is 3, and the number of single laser tubes in the rear row of laser lines is 2. As shown in Figure 4, the asymmetric microdisk cavity is a helical microdisk cavity, and the helix of the helical microdisk cavity is The linear polar coordinate equation is

where ρ(θ) is the polar diameter, ρ ₀ is the characteristic radius, θ is the polar angle, ε is the deformation factor, ρ ₀ is the characteristic radius of the spiral microdisk cavity cavity, and ρ ₀ =200μm, ε=0.1. The distances AB and AC between the light-emitting point A of the single laser tube in the rear row of laser lines and the geometric centers B and C of the two closest laser single tubes in the front row of laser lines are equal, and the angle between AB and AC is ∠ A=90°, AB=AC=900μm, from this, it can be calculated that the geometric center distance of two adjacent laser single tubes in the front row of laser lines is about 1270μm, which offsets the characteristic radius of the two spiral-shaped microdisk cavity cavity, The cavity surfaces corresponding to the two spiral-shaped microdisk cavities are about 870 μm apart. According to the far-field energy distribution diagram of the edge-emitting semiconductor laser of the spiral-shaped microdisk cavity obtained by the experimental measurement, it can be seen that the horizontal divergence angle of the emitted light from the spiral-shaped microdisk cavity is 40°. When the outgoing light passes through the middle of two adjacent laser single tubes in the front row of laser lines, the light beams diverge to nearly 550μm in the horizontal direction, so there will be no thermal superposition phenomenon. The laser array was installed on the heat sink 3 to simulate the heat field of the heat sink, and no obvious thermal superposition phenomenon was found.

Claims (2)

1. an asymmetric micro-disk cavity edge emission semiconductor laser array, the laser single tube (1) that constitutes the laser array is an asymmetric micro-disk cavity edge emission semiconductor laser; it is characterized in that, the front row laser line array, the rear row laser line array are located On the same substrate (2), in the front row of laser lines, 3 to 4 single laser tubes (1) are arranged in line with the same geometric center distance, and in the rear row of laser lines, 2 to 4 single laser tubes are arranged. (1) Arranged according to the same geometric center distance, the geometric center distance of the laser single tubes (1) in the front row of laser lines is the same as the geometric center distance of each laser single tube (1) in the rear row of laser lines; the The light output directions of each single laser tube (1) are the same and face forward, and the optical axis of the output light of the single laser tube (1) in the rear row of laser lines is the geometric center of the nearest single laser tube (1) in the front row of laser lines. 1/2 of the geometric center distance. 2. The asymmetric microdisk cavity edge-emitting semiconductor laser array according to claim 1, wherein the asymmetric microdisk cavity is a spiral microdisk cavity, an elliptical microdisk cavity or a spiral microdisk cavity; The light-emitting point of the single laser tube (1) in the middle is located at the apex angle ∠A of the isosceles triangle ΔABC, and two of the laser lines in the front row closest to the single laser tube (1) in the rear row of laser lines The geometric center of the single laser tube (1) is located at the base angles ∠B and ∠C of the isosceles triangle ΔABC respectively, and ∠A=60°～120°. When the asymmetric microdisk cavity is a snail-shaped microdisk cavity, The waist length AB=AC=500～650μm of the isosceles triangle ΔABC, when the asymmetric microdisk cavity is an oval microdisk cavity, the waist length AB=AC=350～500μm of the isosceles triangle ΔABC, when the asymmetric microdisk cavity is When the cavity is a spiral microdisk cavity, the waist length of the isosceles triangle ΔABC is AB=AC=800-1000 μm.

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