阅读说明：本技术 一种基于半导体增益的低阈值Tamm态等离子激光器 (Low-threshold Tamm-state plasma laser based on semiconductor gain ) 是由 王涛 杨杰 张浩然 常浩泽 王高峰 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种基于半导体增益的低阈值Tamm态等离子激光器,该激光器由衬底,布拉格反射镜(DBRs),有源增益层,金属层和金属圆柱阵列组成。在性能上与传统的激光器相比,本发明的激光器谐振腔具有超窄线宽,进而使得Q值很高,阈值很低。在制备上,在实际的器件制备中用银层代替了传统的上层DBR,减少了激光器的体积。且本发明采用半导体增益材料替代了传统的增益,大大减小了制备工艺的复杂性,同时极大节约了激光器的制作成本,展示出了巨大的应用前景。(The invention discloses a low-threshold Tamm state plasma laser based on semiconductor gain. Compared with the traditional laser in performance, the laser resonant cavity has ultra-narrow linewidth, so that the Q value is high and the threshold value is low. In preparation, the traditional upper DBR is replaced by the silver layer in actual device preparation, and the volume of the laser is reduced. In addition, the semiconductor gain material is adopted to replace the traditional gain, so that the complexity of the preparation process is greatly reduced, the manufacturing cost of the laser is greatly saved, and the laser has a huge application prospect.)

1. A low threshold Tamm state plasma laser based on semiconductor gain is characterized in that: the laser device comprises a laser device structure consisting of a metal cylinder array, and sequentially comprises a substrate (1), a Bragg reflector (2) consisting of materials with different refractive indexes, a semiconductor gain layer (3), a metal layer (4) and the metal cylinder array (5) from bottom to top.

2. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the substrate (1) is made of GaAs, the refractive index is 3.34, and the thickness of the substrate is 1.5 mu m.

3. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the high-refractive index and low-refractive index materials of the Bragg reflector (2) are respectively GaAs/AlGaAs, the refractive indexes are respectively 3.34/2.97, the thickness of the GaAs/AlGaAs is 114nm/130nm, and the logarithm is 30 pairs.

4. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the semiconductor gain layer (3) is made of InGaAsP, the gain spectrum is 1450-1650 nm, and the thickness is 90 nm.

5. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the metal layer (4) is made of silver and has a thickness of 20-40 nm.

6. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the metal cylinder array (5) is made of silver, the height of the silver cylinders is 100-170 nm, the radius of the silver cylinders is 80-130 nm, and the distance between the centers of adjacent cylinders is 350 nm.

7. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the laser works in a 1550nm waveband and has an ultra-narrow linewidth.

8. A semiconductor gain based low threshold Tamm state plasma laser as claimed in claim 1 wherein: the cross section of a single periodic unit of the laser structure is in a shape that four right-angle sectors are cut off at four corners of a square.

Technical Field

The invention relates to the field of micro-nano laser devices, in particular to the structural design and characterization of a Tamm-state plasma laser taking a semiconductor gain material as active gain.

Background

The Tamm state plasma is a novel interface mode, the electric field is localized at the interface of two different materials, the intensity reaches the maximum value, after the interface is far away, the intensity is exponentially attenuated, the Tamm state plasma has no dependence on polarization, the loss is lower, a specific dispersion compensation element is not needed, and the preparation requirement is lower. Because the traditional surface plasma has dependence on polarization and poor performance in long-distance energy transmission, Tamm state plasma is a new direction for research. In the design of lasers, how to make the threshold of the lasers lower and how to make the lasers more compact to integrate in optoelectronic devices have been important issues in the field of laser research. Therefore, in order to generate the optical feedback necessary for the lasing effect, lasers of different geometries have been developed, such as distributed feedback lasers, vertical cavity surface emitting lasers or photonic crystal resonators. However, these structures still have the problems of complex structure, large device size and the like, and the manufacturing difficulty and cost of the laser are increased.

Nowadays, with the development of nano preparation technology, lasers based on different wave bands and different resonant cavity structures are realized one by one, wherein the laser of 1550nm wave band is higher than other wave bands in safety to human eyes and has good penetration capability, and the wave band is located at the lowest loss transmission window of quartz optical fiber, is the optimal working wavelength of optical fiber communication, has wide application in the fields of human eye safety laser ranging, laser radar, remote sensing, laser micromachining, environment detection and the like, and is the hotspot field of current research. However, the current fabrication technology of 1550nm band laser is still immature, and new structure needs to be designed and suitable gain material needs to be found to solve the problem.

Disclosure of Invention

In order to solve the problems of large volume and difficult preparation of the traditional laser, the invention provides a Tamm-state plasma laser based on semiconductor gain, wherein the working waveband is 1550 nm. The technical scheme adopted by the invention is as follows:

the utility model provides a low threshold value Tamm attitude plasma laser based on semiconductor gain, the laser instrument comprises the laser instrument structure by metal cylinder array, from up including the substrate down in proper order, Bragg reflector (DBRs) by different refractive index material constitution, semiconductor gain layer, metal level and metal cylinder array, and the radius of cylinder is defined as R, and the height is defined as H, and the array cycle is defined as D.

Preferably, the substrate is made of GaAs, has a refractive index of 3.34, and has a thickness of 1.5 μm.

Preferably, the DBR is made of materials with different refractive indexes, GaAs/AlGaAs respectively, the refractive index is 3.34/2.97, the thickness of the high-low refractive index material in each DBR is obtained by the formula d ═ λ/4n, so that the thickness of GaAs/AlGaAs is 114nm/130nm, and the number of DBR pairs is 30.

Preferably, the semiconductor gain layer material is InGaAsP, the gain spectrum of the semiconductor gain layer material is 1450-1650 nm, and the thickness of the semiconductor gain layer material is 90 nm.

Preferably, the metal layer is made of silver and has a thickness of 20-40 nm.

Preferably, the metal used by the metal column array is silver, the height of the silver column is 100-170 nm, and the radius of the silver column is 80-130 nm; the distance between the centers of adjacent cylinders is 350 nm.

Preferably, the laser operates in 1550nm band and has ultra-narrow linewidth.

Preferably, the cross section of a single periodic unit of the laser structure is in a shape that four right-angle sectors are cut off at four corners of a square.

The design method of Tamm state plasma laser based on semiconductor gain specifically adopts the following steps,

the method comprises the following steps: calculating the reflectivity of the DBR by using a transmission matrix method through Matlab, adjusting the logarithm of the DBR to enable the logarithm to reach the optimal parameter, and determining the logarithm of the DBR to be 30 pairs; making it have a reflectivity of more than 99.5% at 1550 nm;

step two: FDTD (noise Difference Time domain) is utilized to obtain a reflection spectrum, a resonant cavity mode is found according to the reflection spectrum, the cavity mode is designed to be 1550nm and is overlapped with a gain spectrum.

The invention realizes the design of a Tamm plasma laser by taking the semiconductor gain material InGaAsP as an active gain layer and respectively utilizing DBRs and silver layers with silver column arrays as high-reflectivity mirrors at two sides. On one hand, the existence of the silver column array greatly reduces the threshold value of the laser, and the preparation of the semiconductor gain is not difficult, thereby reducing the preparation difficulty of the device; on the other hand, the silver layer replaces the upper DBR to be used as a high-reflection mirror, so that the volume of the laser and the manufacturing cost are reduced.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic cross-sectional view of a semiconductor gain-based low-threshold Tamm-state plasma laser according to the present invention;

FIG. 2 is a cross-sectional view of a single periodic structure of a semiconductor gain based low threshold Tamm state plasma laser in accordance with the present invention;

FIG. 3 is a reflection spectrum of a DBR mirror of a low threshold Tamm state plasma laser based on semiconductor gain according to the present invention;

FIG. 4 is a reflection spectrum of a semiconductor gain based low threshold Tamm state plasma laser in accordance with the present invention;

FIG. 5 is an input-output curve of a semiconductor gain-based low threshold Tamm state plasma laser in accordance with the present invention;

FIG. 6 is a spectrum of a semiconductor gain-based low-threshold Tamm-state plasma laser simulated by FDTD Solution according to the present invention;

FIG. 7 is a graph of the lateral field distribution of a semiconductor gain-based low-threshold Tamm-state plasma laser simulated by FDTD Solution according to the present invention.

Detailed description of the preferred embodiments

In order to make the technical scheme, the theoretical design method and the device advantages of the invention clearer, the invention is further described in detail with reference to the attached drawings;

the invention provides a low-threshold Tamm state plasma laser based on semiconductor gain; the overall structure of the device is as shown in fig. 1 and 2, and comprises a substrate 1, a DBR2 composed of materials with different refractive indexes, a semiconductor gain layer 3, a metal layer 4 and a metal pillar array 5 in sequence from bottom to top; the substrate 1 is made of GaAs, has a high refractive index, can increase the reflectivity of the bottom, and has a thickness of 1.5 μm; the DBR2 is composed of materials with different refractive indexes, namely GaAs/AlGaAs, the refractive indexes are 3.34/2.97 respectively, 30 pairs of DBRs provide reflectivity of more than 99.5 percent, and the width of a stop band is 150 nm; as shown in fig. 3; the semiconductor gain material is InGaAsP, the gain spectrum of the semiconductor gain material is 1450-1550 nm, and the thickness of the semiconductor gain material is 90 nm; the semiconductor gain material is filled between the DBR and the metal layer to serve as a gain layer, so that the difficulty and the cost are reduced in manufacturing; the metal used by the metal column array 5 is silver, the radius is 100nm, the height is 150nm, the distance between the centers of adjacent columns is 350nm, and the metal column array is filled according to the array period; the cross section of the single-period structure of the laser is in a shape that four right-angle sectors are cut off at four corners of a square, wherein the side length of the square is 350nm, and the radius of the right-angle sector is 110 nm.

The design of the low-threshold Tamm state plasma laser based on the semiconductor gain comprises the following specific steps: firstly, calculating the reflectivity of the DBR by using a transmission matrix method through Matlab, as shown in FIG. 3, adjusting the logarithm optimization of the DBR to achieve the optimal parameter, and determining the logarithm of the DBR to be 30 pairs; then, FDTD is utilized to obtain a reflection spectrum, a resonant cavity mode is found according to the reflection spectrum, the found resonant cavity mode is shown in figure 4, the cavity mode is designed to be 1550nm and is overlapped with the gain spectrum; finally, three-dimensional modeling is carried out by utilizing an FDTD method through Lumrical software according to the optimal parameters, plane waves are selected for pumping in simulation, the pumping wavelength is 1065nm, and the pulse width is 4 ps; monitoring the light spectrum, the transmission spectrum and the field distribution condition by setting a time monitor and a power monitor; FIG. 5 is an input-output curve diagram of a semiconductor gain-based low-threshold Tamm-state plasma laser obtained by FDTD Solution modeling simulation; the simulation results are shown in fig. 6 and 7, which are respectively a spectrogram and a side electric field distribution diagram, and it can be seen that the low-threshold Tamm state plasma laser based on the semiconductor gain, which is designed by the invention, has the line width of 0.72nm and the Q value of 2153;

in conclusion, the design of the low-threshold Tamm-state plasma laser based on the semiconductor gain is simple in structure and small in size, the silver layer is used for replacing the traditional upper DBR in the actual device preparation, the complex preparation process is avoided, the preparation cost of the device is reduced, and the huge application prospect is shown.