阅读说明：本技术 一种基于氮化铝纳米线的激光器 (Laser based on aluminum nitride nanowire ) 是由 王英 叶佳慧 廖常锐 王义平 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种基于氮化铝纳米线的激光器,包括衬底、以及设置在衬底上的单根氮化铝纳米线；所述氮化铝纳米线平行于衬底,所述氮化铝纳米线的两个端面之间形成法布里-珀罗谐振腔。本申请的一种基于氮化铝纳米线的激光器,采用单根氮化铝纳米线作为增益介质,有利于实现波长为280nm以下的激光输出。(The invention discloses a laser based on an aluminum nitride nanowire, which comprises a substrate and a single aluminum nitride nanowire arranged on the substrate; the aluminum nitride nanowire is parallel to the substrate, and a Fabry-Perot resonant cavity is formed between two end faces of the aluminum nitride nanowire. According to the laser based on the aluminum nitride nanowire, a single aluminum nitride nanowire is used as a gain medium, and laser output with the wavelength of below 280nm is facilitated.)

1. A laser based on an aluminum nitride nanowire is characterized by comprising a substrate and a single aluminum nitride nanowire arranged on the substrate; the aluminum nitride nanowire is parallel to the substrate, and a Fabry-Perot resonant cavity is formed between two end faces of the aluminum nitride nanowire.

2. The laser of claim 1, further comprising a femtosecond laser excitation source.

3. The laser of claim 1, wherein the end facets of the aluminum nitride nanowires have a grating structure.

4. The laser of claim 1, wherein the end faces of the aluminum nitride nanowires

Has a film coating layer.

5. The laser of claim 2, wherein the femtosecond laser is an ultraviolet femtosecond laser and the laser is a solar blind ultraviolet laser.

6. The laser of claim 5, wherein the wavelength of the UV femtosecond laser is greater than 200nm and less than 400 nm.

7. The laser of claim 2, wherein the femtosecond laser has a repetition rate tunable from 1kHz to 200 kHz.

8. The laser of claim 1, wherein the substrate is MgF₂A substrate.

9. The laser of claim 1, wherein the aluminum nitride nanowires have a diameter of 0.05-1000 μm.

10. The laser of claim 8, wherein the aluminum nitride nanowires are 10-5000 μ ι η in length.

Technical Field

The invention relates to the technical field of lasers, in particular to a laser based on an aluminum nitride nanowire.

Background

Nanowire lasers are very popular in the fields of data storage, medical, biological, and chemical fluorescence sensing, among other applications. In the existing nanowire laser, the nanowire is CdS (cadmium sulfide), ZnO (zinc oxide), or GaN (gallium nitride), and the radiation wavelength of the nanowire laser already covers the range from near ultraviolet to visible light. Because the wide bandgap semiconductor materials have the advantages of high breakdown electric field, thermal conductivity, electron mobility and the like, the wide bandgap semiconductor materials have great development potential in the fields of high temperature, high frequency, radiation resistance and short wavelength luminescence.

However, the forbidden bandwidth of CdS is 2.45eV, and the corresponding light-emitting wavelength is 507 nm; the forbidden band width of ZnO is 3.2eV, and the corresponding light-emitting wavelength is 390 nm; the forbidden band width of GaN is 3.4eV, and the corresponding light-emitting wavelength is 364 nm. Under optical pumping, the excited radiation of the semiconductor nanowire is usually realized by using pump light with shorter wavelength, which greatly limits the output wavelength range and application of the nanowire laser, and the prior art can only realize the laser output of UV-A (output wavelength 315-.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a laser based on an aluminum nitride nanowire, which comprises a substrate and a single aluminum nitride nanowire arranged on the substrate; the aluminum nitride nanowire is parallel to the substrate, and a Fabry-Perot resonant cavity is formed between two end faces of the aluminum nitride nanowire.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the laser also comprises a femtosecond laser excitation source.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the end face of the aluminum nitride nanowire has a grating structure.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the end face of the aluminum nitride nanowire is provided with a coating layer.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the femtosecond laser is ultraviolet femtosecond laser, and the laser is a solar blind ultraviolet laser.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the wavelength of the ultraviolet femtosecond laser is more than 200nm and less than 400 nm.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the repetition frequency of the femtosecond laser is 1kHz-200kHz and is adjustable.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the substrate is MgF₂A substrate.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the diameter of the aluminum nitride nanowire is 0.05-1000 μm.

As an improvement of the laser based on the aluminum nitride nanowire provided by the invention, the length of the aluminum nitride nanowire is 10-5000 μm.

The application has the following beneficial effects:

the invention provides a laser based on an aluminum nitride nanowire.A single aluminum nitride nanowire is used as a gain medium, and a Fabry-Perot resonant cavity is formed between two end faces of the aluminum nitride nanowire, so that the aluminum nitride nanowire is simultaneously used as the gain medium and the resonant cavity of the laser; the nanowire is an aluminum nitride nanowire, and the aluminum nitride has a super-wide forbidden band width of 6.2eV, so that laser output below 280nm can be realized.

Drawings

FIG. 1 is a schematic diagram of an aluminum nitride nanowire-based laser according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a fabry-perot resonator of a laser based on aluminum nitride nanowires according to an embodiment of the present invention.

Reference numerals:

the device comprises a substrate (1), an aluminum nitride nanowire (2), a femtosecond laser (3), a left end face (5) and a right end face (4).

The specific implementation mode is as follows:

in order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Fig. 1 is a schematic structural diagram of a laser based on aluminum nitride nanowires according to an embodiment of the present invention.

As shown in FIG. 1, the laser based on the aluminum nitride nanowire provided by the invention comprises a substrate (1) and a semiconductor nanowire arranged on the substrate (1). The semiconductor nanowire of the present application is a single aluminum nitride nanowire (2). Wherein the aluminum nitride nanowire (2) is arranged in parallel to the substrate (1).

The aluminum nitride nanowire (2) has good single crystal quality, an atomically smooth surface and a high refractive index, and can effectively restrain light in a sub-wavelength size. The end faces of the aluminum nitride nanowire (2) have a certain reflectivity, so that the left end face (5) and the right end face (4) of the aluminum nitride nanowire (2) form two mirrors, as shown in fig. 2, and a Fabry-perot (F-P) resonant cavity is formed between the two end faces.

The single aluminum nitride nanowire (2) is used as a gain medium, the aluminum nitride has a super-wide forbidden band width of 6.2eV, the corresponding emission wavelength is 200nm-210nm, and laser output below 280nm can be realized. The laser with the structure has better optical mode characteristics, can generate high-brightness laser, and the generated laser is output from the end face of the aluminum nitride nanowire (2).

The laser also comprises an excitation source which can adopt an electric pumping mode or an optical pumping mode. Preferably, the excitation source of the present application is a femtosecond laser (3). The repetition frequency of the femtosecond laser (3) is 1kHz-200kHz and is adjustable, and the femtosecond laser has very high peak power density.

More preferably, the excitation source is an ultraviolet femtosecond laser (3), and the laser is a solar blind ultraviolet laser. The wavelength of the ultraviolet femtosecond laser is more than 200nm and less than 400nm, when the ultraviolet femtosecond laser is adopted, the excitation source is a pumping of two-photon absorption, and the aluminum nitride nanowire (2) realizes the population inversion and the laser output through the two-photon absorption. The solar blind ultraviolet laser output of the aluminum nitride nanowire (2) can be effectively realized by adopting ultraviolet femtosecond laser two-photon excitation with high peak power density. In a specific embodiment, the wavelength of the UV femtosecond laser is in the range of 210-390 nm.

If the adopted femtosecond laser wavelength is less than 200nm, the excitation source is linear pumping of single photon absorption. If the adopted pumping femtosecond laser wavelength is larger than 400nm, the excitation source is a nonlinear pumping of multi-photon absorption, and the efficiency is lower.

The high peak power density ultraviolet femtosecond laser two-photon excitation is preferably adopted in the embodiment of the application, compared with single-photon excitation, the ultraviolet femtosecond laser two-photon excitation has larger penetration depth, more efficient optical coupling can be obtained, non-radiative recombination caused by surface defects of nanowires is reduced, and the laser output performance of a laser is improved.

The aluminum nitride (AlN) has an ultra-wide forbidden band width of 6.2eV, the photon energy of ultraviolet femtosecond laser is 3.1eV-4.8eV according to a known light quantum energy formula E = (hc/lambda), so when the femtosecond laser is used as an excitation source, the aluminum nitride nanowire (2) can simultaneously absorb two femtosecond laser photons, under the action of the ultraviolet femtosecond laser of the external excitation source, electrons of the aluminum nitride nanowire (2) are transited to a high-energy-level state and realize the particle number inversion so as to generate excited radiation, laser with the wavelength of a solar blind ultraviolet band is emitted from the end face, and the output of the solar blind ultraviolet laser with the wavelength of about 200nm can be realized. For example, a solar blind ultraviolet band laser in the reference wavelength range of 200-210nm may be output. Therefore, deeper ultraviolet laser output of the nanowire ultraviolet laser is realized, and the ultraviolet laser in the waveband can be applied to the aspects of optical imaging, positioning identification, medical detection and the like.

The aluminum nitride nanowire (2) is used as a Fabry-Perot (F-P, Fabry-Perot) resonant cavity, stimulated radiation of the structure has good optical mode characteristics under ultraviolet femtosecond laser two-photon excitation, solar blind ultraviolet monochromatic light with high brightness can be generated, generated laser is output from the end face of the aluminum nitride nanowire, and the aluminum nitride nanowire is very suitable for being coupled to nano-photonics components and parts, such as quantum dots, metal nanoparticles, plasma waveguides and biological specimens.

The aluminum nitride nanowire (2) is used as a gain medium, the surface crystallization is good, the end surface is flat, and the diameter of the aluminum nitride nanowire (2) is 0.05-1000 mu m. The length of the aluminum nitride nanowire (2) is 10-5000 mu m.

As a preferable scheme, a grating structure is arranged on the end face of the aluminum nitride nanowire (2). The grating structure is, for example, an FBG grating structure engraved on the end face, and aims to enhance the end face reflection and reduce the mirror loss of the aluminum nitride nanowire. The light wave interacts with the metal grating when propagating in the nanowire and is reflected by the end face, thereby forming gain feedback. In order to improve the end face reflectivity, reduce the lasing threshold and improve the laser output efficiency, the grating structure is arranged on the end face of the aluminum nitride nanowire (2), and a coating layer can be arranged on the end face of the aluminum nitride nanowire (2). The plating film is, for example, a gold film. It is understood, however, that the grating structure and coating are not so limited. As a more preferable mode, the end face may be provided with the plating film and the grating at the same time, and the grating may be engraved on the end face before the plating film is formed.

The substrate (1) of the present embodiment is preferably a MgF2 substrate (1). MgF2 is a low-refractive-index crystal, and can effectively prevent leakage of optical signals.

The laser of the application has wide application in the fields of quantum computing, displaying, lighting, biological and gas sensing, medical diagnosis, high-density storage, material science and the like.

The application has the following beneficial effects:

the invention provides a laser based on an aluminum nitride nanowire.A single aluminum nitride nanowire is used as a gain medium, and a Fabry-Perot resonant cavity is formed between two end faces of the aluminum nitride nanowire, so that the aluminum nitride nanowire is simultaneously used as the gain medium and the resonant cavity of the laser; the nanowire is an aluminum nitride nanowire, and the aluminum nitride has a super-wide forbidden band width of 6.2eV, so that laser output below 280nm can be realized.

It is to be understood that the above-described embodiments are merely illustrative of some, but not restrictive, of the broad invention, and that the appended drawings illustrate preferred embodiments of the invention and do not limit the scope of the invention. This application is capable of embodiments in many different forms and is provided for the purpose of enabling a thorough understanding of the disclosure of the application. Although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to one skilled in the art that the present application may be practiced without modification or with equivalents of some of the features described in the foregoing embodiments. All equivalent structures made by using the contents of the specification and the drawings of the present application are directly or indirectly applied to other related technical fields and are within the protection scope of the present application.