Super-continuous white light nano laser and design scheme thereof

Abstract

The invention relates to a design scheme and a preparation method of a super-continuous white light nano laser. The innovation of the invention lies in that: (1) the adopted cavity is a nano resonant cavity capable of breaking through the optical diffraction limit; (2) the resonant wavelength of the adopted nano optical cavity is continuously adjustable; and (3) excitation can be carried out in an electric pumping mode. The technical core involved in the invention comprises the following steps: (1) obtaining a nanometer optical cavity with continuously tunable wavelength; (2) a nanometer optical cavity is adopted, and a periodic surface plasmon array substrate is optimized; and (3) integration of the continuously adjustable nano optical cavity and the white light seed light source. The super-continuous white light nanometer laser reduces dependence on complex optical elements and accurate alignment, overcomes the defect that the laser wavelength cannot be continuously adjusted, and has the advantages of being low in production cost, convenient to operate and good in performance.

Description

Technical Field

[0001] The present invention relates to the fields of nano laser technology and micro-nano optics, and in particular to a design scheme and a preparation method of a supercontinuum white light nano laser. Background Art

[0002] Monochromaticity is one of the excellent qualities of lasers. White light laser refers to a laser device with continuously adjustable wavelength. It not only has the excellent properties of monochromatic lasers such as directionality and polarization, but also has the advantage of a wide frequency coverage range. Compared with ordinary white light, white light lasers have the advantages of high peak power, strong directionality, good polarization, and strong spatial and temporal coherence. At present, white light lasers have been used in laser cutting, welding, medical imaging, military target indication and other fields, but traditional fiber, solid-state and gas white light lasers are limited by large size, susceptibility to temperature fluctuations and vibrations, poor stability and other issues, and cannot meet the needs of miniaturization and integration.

[0003] In the past decade, some progress has been made in the development of white-light lasers based on micron-scale optical cavities. Representative white-light radiation is achieved based on a combination of RGB three-color lasers or a mixture of blue lasers and yellow phosphors, but these methods require complex optical components and precise alignment, limiting the development of integrated applications. In recent years, with the emergence of new gain materials such as semiconductor nanosheets, colloidal quantum dots, and perovskites, optical feedback "cavities" including Fabry-Perot (FP) cavities, random laser (RC) cavities, distributed feedback (DFB) cavities, and whispering gallery mode (WGM) cavities have been constructed to support the simultaneous generation of RGB or RYGB lasers, providing new possibilities for white-light lasers, but how to effectively couple these emitters to multiple cavity modes remains a challenge.

[0004] Nanolasers are coherent light sources at the nanoscale, which will have revolutionary applications in super-resolution imaging, ultra-sensitive sensing, and as on-chip light sources in the field of optoelectronic interconnection. Accordingly, the idea, design, and application of supercontinuum white light nanolasers will be milestone inventions. However, there is no report on supercontinuum white light nanolasers. The main reason is the lack of nano-optical cavities: the optical cavity required for nanolasers must be able to break through the optical diffraction limit. However, this requirement is already difficult for monochromatic nanolasers, not to mention continuously adjustable nano-optical cavities. Therefore, the development of supercontinuum white light nanolasers requires not only technological breakthroughs, but also scientific innovations. Summary of the invention

[0005] In view of the deficiencies pointed out in the above background technology, the purpose of the present invention is to provide a design scheme and preparation method for a continuous white light nanolaser. The innovative points include: (1) obtaining a continuously adjustable nano-optical cavity; (2) combining the above "cavity" with a gain medium; and (3) the working mode of a supercontinuum white light nanolaser.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] (1) Preparation of periodic surface plasmon arrays and optimization of their properties, aiming to obtain continuously tunable nano-optical cavities;

[0008] (2) Optimization of periodic surface plasmon array substrate materials;

[0009] (3) Obtaining white light radiation source;

[0010] (4) Combining the periodic surface plasmon array optimized in steps (1) and (2) with the white light radiation source obtained in (3);

[0011] (5) Realize nano-laser with continuously tunable wavelength;

[0012] (6) Obtain white light nanolaser output.

[0013] In step (1), there are no strict requirements on the preparation method of the periodic surface plasmon array, including but not limited to direct writing lithography, nanoimprinting, ultraviolet holographic lithography, etc.

[0014] In step (1), there is no strict requirement for the arrangement of the periodic surface plasmon array, including but not limited to orthogonal arrangement, regular hexagonal arrangement or other arrangements.

[0015] In step (1), there is no strict requirement on the shape of the periodic surface plasmon array nanoparticles, including but not limited to spheres, cylinders, bow ties or other polygons.

[0016] In step (1), there is no strict requirement on the coating material of the periodic surface plasmon array, including but not limited to gold, silver, aluminum, copper, semiconductors, etc.

[0017] In step (1), there is no strict requirement for the coating thickness of the periodic surface plasmon array, which can be 50-200 nm.

[0018] In step (2), there are no strict requirements on the transparent periodic surface plasmon array substrate material, including but not limited to glass, quartz, flexibility, etc.

[0019] In step (3), there are no strict requirements on the composition of the white light radiation source, including but not limited to the combination of a blue light chip and yellow phosphor, a UV chip and a red, green and blue composite fluorescent material, and a red, green and blue three-primary color chip.

[0020] There is no strict requirement for the type of white light radiation source described in step (3), including but not limited to COB LED, QLED, PeLED, OLED and other light sources.

[0021] The integration of the periodic surface plasmon array and the white light radiation source in step (4) includes but is not limited to direct bonding and integrated manufacturing.

[0022] The present invention has the following advantages:

[0023] 1. The present invention realizes a continuously tunable nano-optical cavity, which has the advantage of being able to be tuned within a wide wavelength range.

[0024] 2. The periodic surface plasmon array prepared by the present invention serves as a nano-optical cavity, which breaks through the optical diffraction limit and can generate coherent light at the nanoscale, thus providing possibilities for high-density optoelectronic integration and fine optical operations.

[0025] 3. The present invention achieves high integration of the periodic surface plasmon array and the white light radiation source by optimizing the substrate material, thus meeting the requirements of miniaturization and integration.

[0026] 4. The present invention fully utilizes the luminescence advantages of a wide-spectrum white light radiation source and organically integrates the field enhancement effect and wavelength tunability of a periodic plasmon array to solve the challenge of effectively coupling YRGB emissions to multiple cavity modes at the same time.

[0027] 5. The present invention overcomes the complexity and high cost problems in the preparation process of traditional white light lasers, and achieves the dual advantages of cost-effectiveness and ease of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of the preparation of the periodic surface plasmon array provided by an embodiment of the present invention.

[0029] In the figure: 1-glass substrate; 2-photoresist; 3-plated metal; 4-ultraviolet curing agent; 5-substrate.

[0030] Figure 2 It is a SPR reflection spectrum diagram of surface plasmon arrays with different periods provided by an embodiment of the present invention.

[0031] In the figure: 1-period P = 330nm; 2-period P = 390nm; 3-period P = 425nm; 4-period P = 600nm.

[0032] Figure 3 It is a SPR reflection spectrum diagram of periodic surface plasmon arrays on different substrates provided in the embodiments of the present invention.

[0033] In the figure: 1-glass substrate; 2-flexible substrate; 3-WLED substrate.

[0034] Figure 4 Schematic diagram of a white light radiation source provided in an embodiment of the present invention.

[0035] In the figure: 1-substrate; 2-n-gallium nitride; 3-quantum well MQW; 4-p-gallium nitride.

[0036] Figure 5 It is a schematic diagram of a supercontinuum white light nanolaser provided in an embodiment of the present invention.

[0037] In the figure: 1- Lens.

[0038] Figure 6 It is a nano-laser spectrum diagram with continuously adjustable wavelength and its polarization diagram provided in the embodiment of the present invention.

[0039] Figure 7 It is a white light nano-laser spectrum diagram and its polarization diagram provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] 1. Preparation and screening of a periodic surface plasmon provided by the present invention Figure 1-3 The detailed steps are as follows:

[0042] (1) Preparation of periodic surface plasmon arrays: First, the glass substrate is cleaned and a positive photoresist is spin-coated. Next, the photoresist is pattern-exposed using a holographic lithography method and developed using a developer. After development, the photoresist is fixed with clean water and blown dry with nitrogen. Then, metal deposition is performed using the photoresist pattern as a template to obtain a surface plasmon array consistent with its surface morphology. Finally, a UV curing agent is used to transfer the pattern to prepare a wavelength-tunable nano-optical resonant cavity, such as Figure 1 shown.

[0043] (2) Screening of periodic surface plasmon arrays: By using different holographic lithography elements and exposure times, plasmon arrays with different periods and spectral properties can be obtained. By comparing the SPR reflection spectra of four plasmon arrays with different periods, it is found that the tunable wavelength range of the array with period p = 425nm is closest to the white light radiation source to the greatest extent, such as Figure 2 shown.

[0044] (3) Substrate optimization of periodic surface plasmon arrays: By transferring the plasmon array after metal deposition to glass, flexible transparent material PC and white light source, surface plasmon arrays on different substrates can be obtained. Their SPR spectra are as follows: Figure 3 As shown, it aims to achieve efficient integration with the gain medium.

[0045] 2. The design scheme of a supercontinuum white light nano-laser provided by the present invention is as follows Figure 4-7 The detailed steps are as follows:

[0046] (4) Obtaining a white light radiation source: Select sapphire or aluminum nitride as the substrate, deposit a gallium nitride n-type semiconductor layer, an alternating gallium germanium and gallium nitride quantum well structure, and a doped gallium nitride p-type semiconductor layer in sequence, and apply YAG:Ce yellow phosphor on the top. Finally, the chip is surface treated and metal electrodes are made to complete the preparation of the white light radiation source, such as Figure 4 As shown, or directly choose commercial LEDs.

[0047] (5) Combination of periodic surface plasmon arrays and white light radiation sources: through direct bonding or integrated manufacturing, such as Figure 5 As shown;

[0048] (6) Nanolasers with continuously adjustable wavelengths: Spectral acquisition of the integrated nanolasers can produce nanolasers with good directivity, linear polarization characteristics and continuously adjustable wavelengths in the visible light range, such as Figure 6 shown.

[0049] (7) Output of white light nanolaser: By focusing a continuous and tunable nanolaser within a certain range at one point, the output of white light nanolaser can be obtained. This laser not only has a brighter spot than ordinary white light, but also has good linear polarization characteristics, such as Figure 7 shown.

[0050] In specific implementation cases, different white light radiation sources can be prepared by changing the preparation method and the luminescent material.

[0051] In a specific implementation case, different periodic surface plasmon arrays can be prepared by changing the grating period and the metal material.

[0052] The above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A design scheme and preparation method of a supercontinuum white light nano-laser, comprising the following steps: (1) Preparation of periodic surface plasmon arrays and optimization of their properties, aiming to obtain continuously tunable nano-optical cavities; (2) Optimization of periodic surface plasmon array substrate materials; (3) Obtaining white light radiation source; (4) Combining the periodic surface plasmon array optimized in steps (1) and (2) with the white light radiation source obtained in (3); (5) Realize nano-laser with continuously tunable wavelength; (6) Obtain white light nanolaser output.

2. The preparation method according to claim 1, characterized in that In step (1), the preparation method of the periodic surface plasmon array can be direct writing lithography, nanoimprinting, ultraviolet holographic lithography, etc.

3. The preparation method according to claim 1, characterized in that: In step (1), the arrangement of the periodic surface plasmon array can be an orthogonal arrangement, a regular hexagonal arrangement or other arrangements.

4. The preparation method according to claim 1, characterized in that: In step (1), the shape of the periodic surface plasmon array nanoparticles can be a sphere, a cylinder, a bow tie or other polygons.

5. The preparation method according to claim 1, characterized in that: In step (1), the coating material of the periodic surface plasmon array can be gold, silver, aluminum, copper, semiconductor, etc.

6. The preparation method according to claim 1, characterized in that: In step (1), the coating thickness of the periodic surface plasmon array can be 50-200 nm.

7. The preparation method according to claim 1, characterized in that: In step (3), the composition of the white light radiation source can be a combination of a blue light chip and yellow phosphor, a combination of a UV chip and a red, green and blue composite fluorescent material, and a combination of a red, green and blue primary color chip.

8. The preparation method according to claim 1, characterized in that: In step (3), the type of white light radiation source can be COB LED, QLED, PeLED, OLED and other light sources.

9. The preparation method according to claim 1, characterized in that: In step (4), the periodic surface plasmon array and the white light radiation source may be integrated by direct bonding or integrated manufacturing.

10. The design and preparation method of a supercontinuum light nanolaser according to any one of claims 1 to 9, characterized in that: The supercontinuum white light nanolaser integrates a plasmon nano-optical cavity with continuously tunable wavelength and a broad-spectrum white light radiation source. The periodic surface plasmon array has the characteristics of breaking through the optical diffraction limit, super-strong field enhancement effect and wavelength coordination in the visible light range. The white light radiation source can be prepared by mature semiconductor technology. The efficient combination of the two realizes the output of white light nanolaser.

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