CN110323668A - A kind of infrared narrowband emitter - Google Patents

Abstract

The invention discloses an infrared narrow-band radiator. The infrared narrowband radiator produces medium and long-wave infrared narrowband radiation with a preset frequency _vIR , which includes a substrate grown sequentially from bottom to top, a pump light source, a first infrared resonant cavity, an infrared gain medium and a second infrared resonant cavity; Or it includes a substrate grown sequentially from bottom to top, a pumping light source and an infrared resonant cavity doped with an infrared gain medium. The forbidden band width of the infrared gain medium is equal to the energy of the required medium and long-wave infrared light. The infrared gain medium absorbs the pump light emitted by the pump light source to generate hot carriers. Multiple electron-hole pairs are generated at the edge of the energy band, and multiple electron-hole pairs provide gain for mid- and long-wave infrared light with a frequency v _IR through radiative recombination, and the frequency of the pump light is v _pump >2v _IR . The invention improves the radiation power spectrum density and directivity without the single crystal epitaxial growth of the medium and long wave infrared gain medium.

Description

An infrared narrowband radiator

technical field

The invention relates to the technical field of photo-thermal-electric energy conversion, in particular to an infrared narrow-band radiator.

Background technique

Mid- and long-wave infrared light sources are widely used in many fields such as gas detection and biological target detection. Taking gas detection as an example, many gas molecules have characteristic absorption peaks in the medium and long-wave infrared band, which are called fingerprint regions. The infrared light of these wavelengths is emitted by an infrared light source. If such molecules exist, the infrared light will be absorbed and the signal will be weakened. By detecting the intensity of the infrared signal, the existence of the corresponding molecule and its relative concentration can be detected. Different gas molecules have different fingerprint areas, the fingerprint area coverage ranges from a few nanometers to tens of nanometers, and the center wavelength range is also different. Therefore, narrow-band radiation requirements are put forward for medium and long-wave infrared light sources.

The existing medium and long-wave infrared narrowband radiators mainly have the following two implementation schemes: 1) medium and long-wave infrared quantum cascade lasers; 2) medium and long-wave infrared narrow-band thermal radiators.

Mid- and long-wave infrared quantum cascade lasers have good monochromatic characteristics, high spectral power density, and fast modulation, but often require single-crystal epitaxial growth of mid- and long-wave infrared gain media on the order of more than μm or even 10 μm, and the cost is extremely high. It has become the main factor limiting its application in medium and long-wave infrared detection.

The mid- and long-wave infrared narrow-band thermal radiator constructs a radiator surface with mid- and long-wave narrow-band absorption characteristics, and according to Kirchhoff's law, after heating the radiator, the radiator emits narrow-band mid- and long-wave infrared radiation to the outside. For any thermal radiator, its far-field radiation power spectral density cannot exceed that of a black body at the same temperature, so it has the disadvantage of low radiation power spectral density; in addition, because it is difficult to achieve particle number inversion by simple heating, the thermal radiator only has a resonator Without a gain medium, its spectral power spectrum is relatively broad, and the directivity of the radiation is relatively poor.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

The purpose of the present invention is to provide a monolithically integrated medium and long-wave infrared narrow-band radiator, which can achieve higher radiation power spectral density and directivity without the need for single crystal epitaxial growth of medium and long-wave infrared gain media, and has the advantages of preparation The method is simple and the cost is low.

To achieve the above object, the present invention provides the following scheme:

An infrared narrowband radiator, the infrared narrowband radiator includes a substrate grown sequentially from bottom to top, a pump light source, a first infrared resonant cavity, an infrared gain medium and a second infrared resonant cavity; the infrared narrowband radiator is used to generate mid- to long-wave infrared narrow-band radiation at a predetermined frequency v _IR ;

The infrared gain medium is used to absorb the pump light emitted by the pump light source to generate medium and long-wave infrared light, and the frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR ; The forbidden band width of the infrared gain medium is equal to the energy of the medium and long-wave infrared light; the first infrared resonant cavity and the second infrared resonant cavity are both formed by stacking N resonant units from bottom to top, wherein N≥2; the first infrared resonant cavity and the second infrared resonant cavity are used to resonate and frequency-select the mid- and long-wave infrared light, so as to generate mid- and long-wave infrared narrowband radiation with a preset frequency _vIR .

Optionally, the infrared gain medium is a narrow-bandgap semiconductor with multiple excitonic effects or a metalloid with multiple exciton effects;

The narrow bandgap semiconductor is one or more of PbSe nano quantum dots, PbS nano quantum dots, PbTe nano quantum dots, InAs nano quantum dots, InP nano quantum dots, CdSe nano quantum dots and CdTe nano quantum dots;

The metalloid is one or more of Sn nano quantum dots, CdHgTe nano quantum dots, Ag ₂ S nano quantum dots, CuAg nano quantum dots, carbon nanotubes and graphene.

Optionally, the size range of each nano quantum dot is 1-1000 nm.

Optionally, both the first infrared resonant cavity and the second infrared resonant cavity are one-dimensional photonic crystals;

The one-dimensional photonic crystal is a mid-to-long-wave infrared Bragg reflection grating or a mid-to-long-wave infrared distributed feedback grating; the resonant frequency of the one-dimensional photonic crystal is equal to the preset frequency v _IR .

Optionally, the resonant unit includes a first resonant layer and a second resonant layer arranged from bottom to top;

The first resonant layer is one or more of MgF ₂ layers, CaF ₂ layers, BF ₂ layers, YF ₃ layers, SrF ₂ layers, KBr layers and ZnS layers, and the second resonant layer is Ge layer and One or more of the Si layers.

The present invention also provides an infrared narrowband radiator, which includes a substrate grown sequentially from bottom to top, a pump light source, and an infrared resonant cavity doped with an infrared gain medium; the infrared narrowband radiator is used to generate mid- to long-wave infrared narrow-band radiation at a predetermined frequency v _IR ;

The infrared resonant cavity doped with an infrared gain medium is formed by stacking N resonant units doped with an infrared gain medium from bottom to top, wherein N≥2; the infrared resonant cavity doped with an infrared gain medium It is used to absorb the pump light emitted by the pumping light source to generate mid- and long-wave infrared light, and perform resonance frequency selection on the mid- and long-wave infrared light to generate mid- and long-wave infrared narrow-band radiation with a preset frequency v _IR ; the The frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR ; the forbidden band width of the infrared gain medium is equal to the energy of the medium and long-wave infrared light.

Optionally, the infrared gain medium is a narrow-bandgap semiconductor with multiple excitonic effects or a metalloid with multiple exciton effects;

The narrow bandgap semiconductor is one or more of PbSe nano quantum dots, PbS nano quantum dots, PbTe nano quantum dots, InAs nano quantum dots, InP nano quantum dots, CdSe nano quantum dots and CdTe nano quantum dots;

The metalloid is one or more of Sn nano quantum dots, CdHgTe nano quantum dots, Ag ₂ S nano quantum dots, CuAg nano quantum dots, carbon nanotubes and graphene.

Optionally, the size range of each nano quantum dot is 1-1000 nm.

Optionally, the infrared resonator doped with an infrared gain medium is a one-dimensional photonic crystal;

The one-dimensional photonic crystal is a mid-to-long-wave infrared Bragg reflection grating or a mid-to-long-wave infrared distributed feedback grating; the resonant frequency of the one-dimensional photonic crystal is equal to the preset frequency v _IR .

Optionally, the resonant unit doped with an infrared gain medium includes a first resonant layer doped with an infrared gain medium and a second resonant layer doped with an infrared gain medium arranged from bottom to top;

The first resonant layer doped with infrared gain medium is MgF ₂ layer doped with infrared gain medium, CaF ₂ layer doped with infrared gain medium, BF ₂ layer doped with infrared gain medium, doped with One or more of the YF ₃ layer doped with the infrared gain medium, the SrF ₂ layer doped with the infrared gain medium, the KBr layer doped with the infrared gain medium, and the ZnS layer doped with the infrared gain medium, the second The resonant layer doped with the infrared gain medium is one or more of the Ge layer doped with the infrared gain medium and the Si layer doped with the infrared gain medium.

Compared with prior art, the beneficial effect of the present invention is:

The invention proposes an infrared narrowband radiator. The infrared narrow-band radiator is a monolithically integrated medium and long-wave infrared narrow-band radiator, which includes a substrate grown sequentially from bottom to top, a pump light source, a first infrared resonant cavity, an infrared gain medium, and a second infrared resonant cavity; or It includes a substrate grown sequentially from bottom to top, a pump light source, and an infrared resonant cavity doped with an infrared gain medium; an infrared narrowband radiator is used to generate medium and long-wave infrared narrowband radiation with a preset frequency _vIR . The forbidden band width of the infrared gain medium is equal to the energy of the required medium and long-wave infrared light. The infrared gain medium absorbs the pump light emitted by the pump light source to generate hot carriers. Multiple electron-hole pairs are generated at the edge of the energy band, and multiple electron-hole pairs provide gain for mid- to long-wave infrared light of frequency v _IR through radiative recombination. The frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR . The invention improves the radiation power spectral density and the radiation directionality without the need of single crystal epitaxial growth of the medium and long wave infrared gain medium; and has the advantages of simple preparation method and low cost.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 is the structural representation of a kind of infrared narrowband radiator of embodiment 1 of the present invention;

Fig. 2 is a schematic structural view of an infrared narrowband radiator according to Embodiment 2 of the present invention;

FIG. 3 is a schematic diagram of the working principle of the mid-infrared gain medium in Embodiments 1 and 2 of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

Fig. 1 is a schematic structural diagram of an infrared narrowband radiator according to Embodiment 1 of the present invention.

Referring to Fig. 1, the infrared narrowband radiator of the present embodiment comprises a substrate 1, a pumping light source 2, a first infrared resonant cavity 3, an infrared gain medium 4 and a second Infrared resonant cavity 5; the infrared narrowband radiator is used to generate medium and long wave infrared narrowband radiation with preset frequency _vIR .

The infrared gain medium 4 is used to absorb the pump light emitted by the pump light source 2 to generate medium and long-wave infrared light, and the frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR ; the forbidden band width of the infrared gain medium 4 is equal to the energy of the medium and long-wave infrared light, the energy of the medium and long-wave infrared light E _g =hv _IR , h represents Planck's constant; the first infrared resonant cavity 3 and The structure of the second infrared resonant cavity 5 is the same, and they are all formed by stacking N resonant units sequentially from bottom to top, where N≥2; the first infrared resonant cavity 3 and the second infrared resonant cavity 5 A mode selection mechanism is provided for the mid- and long-wave infrared light, which is used for resonantly frequency-selecting the mid- and long-wave infrared light, so as to generate mid- and long-wave infrared narrowband radiation with a preset frequency _vIR .

As an optional implementation, the infrared gain medium 4 is a narrow bandgap semiconductor with multiple excitonic effects or a metalloid with multiple excitonic effects; the narrow bandgap semiconductor is PbSe nano quantum dots, PbS nano One or more of quantum dots, PbTe nano-quantum dots, InAs nano-quantum dots, InP nano-quantum dots, CdSe nano-quantum dots and CdTe nano-quantum dots; the metalloid is Sn nano-quantum dots, CdHgTe nano-quantum dots, One or more of Ag ₂ S nanometer quantum dots, CuAg nanometer quantum dots, carbon nanotubes and graphene. The size range of each nanometer quantum dot is 1-1000nm. In this embodiment, PbSe nano quantum dots are used to generate photoinduced hot carriers as a gain medium for visible light-infrared light conversion, that is, the infrared gain medium 4 is PbSe nano quantum dots.

As an optional implementation, both the first infrared resonant cavity 3 and the second infrared resonant cavity 5 are one-dimensional photonic crystals; the one-dimensional photonic crystals are medium-long-wave infrared Bragg reflection gratings or medium-long-wave infrared Distributed feedback grating; the resonant frequency of the one-dimensional photonic crystal is equal to the preset frequency v _IR . The resonant unit includes a first resonant layer 31 and a second resonant layer 32 arranged from bottom to top; the first resonant layer 31 is MgF ₂ layers, CaF ₂ layers, BF ₂ layers, YF ₃ layers, SrF ₂ layers , KBr layer and ZnS layer, and the second resonant layer 32 is one or more of Ge layer and Si layer. In this embodiment, both the first infrared resonant cavity 3 and the second infrared resonant cavity 5 are MgF ₂ /Ge periodic one-dimensional photonic crystals; the first resonant layer 31 is a MgF ₂ layer, and the second infrared resonant cavity The second resonant layer 32 is a Ge layer.

As an optional implementation, both the first infrared resonant cavity 3 and the second infrared resonant cavity 5 are two-dimensional photonic crystals; It is composed of medium and long-wave infrared gain medium materials; the resonant frequency of the two-dimensional photonic crystal is equal to the preset frequency v _IR .

In this embodiment, the pumping light source 2 is a blue GaN-based LED.

The preparation process and working principle of the infrared narrowband radiator in this embodiment will be introduced below.

1) Preparation process:

On a blue-light GaN-based LED tube core epitaxial wafer that has completed the post-process but has not been packaged, periodic MgF ₂ /Ge is deposited by electron beam evaporation, and the number of cycles is not less than 2 to form the first infrared resonant cavity 3 . A cycle of MgF ₂ /Ge is a resonant unit, the MgF ₂ layer is used as the first resonant layer 31, and the Ge layer is the second resonant layer 32. The optical path of MgF ₂ and Ge in each cycle is the required medium and long wave infrared light vacuum A quarter of the wavelength, that is, n _MgF2 × d _MgF2 = n _Ge × d _Ge = λ _{0 -IR} / ₄ , where n _MgF2 represents the refractive index of MgF2, d _MgF2 represents the thickness of MgF2, and n _Ge represents Ge The refractive index of , d _Ge represents the thickness of Ge, and λ _0-IR represents the vacuum wavelength of the desired mid- and long-wave infrared light.

Spin coating PbSe nano quantum dot suspension, the size range of the PbSe nano quantum dot is 1 ~ 100nm, the forbidden band width corresponding to the PbSe nano quantum dot is equal to the energy of the required medium and long wave infrared light, that is E _g-PbSe = hv _IR . v _IR is the preset frequency, which is the frequency of the desired medium and long wave infrared light.

Periodic MgF ₂ /Ge is deposited by electron beam evaporation, and the number of periods is not less than 2 to form the second infrared resonant cavity 5 . A cycle of MgF ₂ /Ge is a resonant unit, the MgF ₂ layer is used as the first resonant layer 31, and the Ge layer is the second resonant layer 32. The optical path of MgF ₂ and Ge in each cycle is the required medium and long wave infrared light vacuum A quarter of the wavelength, that is, n _MgF2 ×d _MgF2 =n _Ge ×d _Ge =λ _0-IR /4.

2) Working principle

Power on the blue GaN-based LED tube core to generate blue light with a vacuum wavelength λ _0-pump ≈ 410nm (hv _pump ≈ 3eV) as pump light, where λ _0-pump represents the wavelength of the pump light emitted by the pump light source, and v _pump Indicates the frequency of the pump light emitted by the pump light source. The forbidden band width E _g-PbSe of PbSe nano-quantum dots is ≈0.375eV, which is about 1/8 of the pump photon energy. Under the irradiation of pump light, PbSe nano-quantum dots generate photo-induced thermal carriers through transition, and the photo-induced thermal carriers relax to the energy band edge of PbSe to generate new electron-hole pairs. In this process, each PbSe nano-quantum dot can generate up to seven electron-hole pairs at the band edge for every pump photon absorbed. These electron-hole pairs emit infrared light with a peak vacuum wavelength λ _0-IR ≈3280nm (hv _pump ≈0.375eV) through direct recombination. The periodic MgF ₂ /Ge on both sides (the first infrared resonant cavity 3 and the second infrared resonant cavity 5) performs resonant frequency selection on the infrared light emitted by the quantum dots in the form of Bragg reflection, and finally generates a free space wavelength λ _0-IR ≈3280nm (hv _pump ≈0.375eV) narrow-band infrared radiation.

The infrared narrow-band radiator in Example 1 generates narrow-band radiation of mid- and long-wave infrared through monolithic integration, and realizes the improvement of radiation power spectral density and radiation without the need for single-crystal epitaxial growth of mid- and long-wave infrared gain media. directionality; and has the advantages of simple preparation and low cost.

Example 2

Fig. 2 is a schematic structural diagram of an infrared narrowband radiator according to Embodiment 2 of the present invention.

Referring to Fig. 2, the infrared narrowband radiator of the present embodiment, the infrared narrowband radiator comprises a substrate 1, a pumping light source 2 and an infrared resonant cavity 6 doped with an infrared gain medium that are grown sequentially from bottom to top; Infrared narrowband radiators are used to generate mid- and long-wave infrared narrowband radiation at a preset frequency v _IR .

The infrared resonant cavity 6 doped with an infrared gain medium is formed by stacking N resonant units doped with an infrared gain medium from bottom to top, wherein N≥2; the infrared resonator doped with an infrared gain medium The cavity 6 is used to absorb the pumping light emitted by the pumping light source to generate medium and long-wave infrared light, and perform resonant frequency selection on the medium and long-wave infrared light to generate medium and long-wave infrared narrow-band radiation with a preset frequency v _IR ; The frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR ; the forbidden band width of the infrared gain medium is equal to the energy of the medium and long-wave infrared light.

As an optional implementation, the infrared gain medium is a narrow bandgap semiconductor with multiple excitonic effects or a metalloid with multiple excitonic effects; the narrow bandgap semiconductor is PbSe nano quantum dots, PbS nano quantum dots point, PbTe nano quantum dots, InAs nano quantum dots, InP nano quantum dots, CdSe nano quantum dots and CdTe nano quantum dots; the metalloid is Sn nano quantum dots, CdHgTe nano quantum dots, Ag One or more of ₂ S nanometer quantum dots, CuAg nanometer quantum dots, carbon nanotubes and graphene. The size range of each nanometer quantum dot is 1-1000nm. In this embodiment, CdHgTe (CHT) nano quantum dots are used to generate photoinduced thermal carriers as a gain medium for visible light-infrared light conversion, that is, the doped infrared gain medium is CdHgTe (CHT) nano quantum dots.

As an optional implementation, the infrared resonant cavity 6 doped with an infrared gain medium is a one-dimensional photonic crystal; the one-dimensional photonic crystal is a mid-long wave infrared Bragg reflection grating or a mid-long wave infrared distribution feedback grating; The resonant frequency of the one-dimensional photonic crystal is equal to the preset frequency v _IR . The resonant unit doped with an infrared gain medium includes a first resonant layer 61 doped with an infrared gain medium and a second resonant layer 62 doped with an infrared gain medium arranged from bottom to top; the first doped The resonant layer 61 with infrared gain medium is MgF ₂ layers doped with infrared gain medium, CaF ₂ layers doped with infrared gain medium, BF ₂ layers doped with infrared gain medium, YF doped with infrared gain medium ₃ layers, one or more of SrF ₂ layers doped with infrared gain medium, KBr layer doped with infrared gain medium and ZnS layer doped with infrared gain medium, the second doped with infrared gain medium The resonant layer 62 of the medium is one or more of a Ge layer doped with an infrared gain medium and a Si layer doped with an infrared gain medium. In this embodiment, the infrared resonant cavity 6 doped with an infrared gain medium is ZnS/Ge periodic one-dimensional photonic crystal; the first resonant layer 61 doped with an infrared gain medium is a doped CdHgTe (CHT ) ZnS layer of nano quantum dots, the second resonant layer 62 doped with infrared gain medium is a Ge layer doped with CdHgTe (CHT) nano quantum dots.

As an optional implementation, the infrared resonant cavity 6 doped with an infrared gain medium is a two-dimensional photonic crystal; Gain medium material; the resonant frequency of the two-dimensional photonic crystal is equal to the preset frequency v _IR .

In this embodiment, the pumping light source 2 is a red AlGaInP-based LED.

The preparation process and working principle of the infrared narrowband radiator in this embodiment will be introduced below.

1) Preparation process:

On a red AlGaInP-based LED die epitaxial wafer that has completed the back-end process but has not been packaged, electron beam evaporation is used to evaporate ZnS/Ge doped with CdHgTe nano-quantum dots. The number of cycles is not less than 2, forming a doped infrared Gain medium for infrared resonator 6 . One cycle of ZnS/Ge is a resonant unit doped with an infrared gain medium, the ZnS layer doped with CdHgTe nanometer quantum dots is used as the first resonant layer 61 doped with an infrared gain medium, and the ZnS layer doped with CdHgTe nanometer quantum dots The Ge layer is the second resonant layer 62 doped with an infrared gain medium, and the optical path doped with CdHgTe quantum dots ZnS and Ge in each period is a quarter of the vacuum wavelength of the required medium and long-wave infrared light, that is, n _{ZnS -CHT} × d _ZnS-CHT = n _Ge-CHT × d _Ge-CHT = λ _0-IR /4, where n _ZnS-CHT represents the refractive index of the ZnS layer doped with CdHgTe nano-quantum dots, and d _ZnS-CHT represents The thickness of the ZnS layer doped with CdHgTe nano-quantum dots, nGe _-CHT represents the refractive index of the Ge layer doped with CdHgTe nano-quantum dots, and _dGe-CHT represents the thickness of the Ge layer doped with CdHgTe nano-quantum dots. The size of the CdHgTe nanometer quantum dot is 1-100nm, and the corresponding forbidden band width is equal to the energy of the required medium and long-wave infrared light, that is, E _g-CHT =hv _IR .

2) Working principle

The red AlGaInP-based LED tube core is energized to generate red light with a vacuum wavelength λ _0-pump ≈650nm (hv _pump ≈1.91eV) as pump light. The forbidden band width E _g-CHT of CdHgTe quantum dots is ≈0.477eV, which is about 1/4 of the pump photon energy. Under the irradiation of pump light, CdHgTe quantum dots generate photoinduced hot carriers through transition, and the photoinduced hot carriers relax to the band edge of CdHgTe to generate new electron-hole pairs. In this process, each CdHgTe quantum dot can generate up to three electron-hole pairs at the band edge for every pump photon absorbed. These electron-hole pairs emit infrared light with a peak vacuum wavelength λ _0-IR ≈2600nm (hv _pump ≈0.477eV) through direct recombination. Periodic ZnS/Ge performs frequency selection on the infrared light emitted by quantum dots in the form of distributed feedback, that is, frequency selection feedback is performed while generating gain, and finally produces a free space wavelength λ _0-IR ≈2600nm (hv _pump ≈0.477eV) narrowband infrared radiation.

The infrared narrow-band radiator in Example 2 generates narrow-band radiation of mid- and long-wave infrared through monolithic integration, and realizes the improvement of radiation power spectral density and radiation without the need for single-crystal epitaxial growth of mid- and long-wave infrared gain media. directionality; and has the advantages of simple preparation and low cost.

Although the infrared narrowband radiators in the above-mentioned embodiments 1 and 2 are different in structure, they are essentially realized based on the same working principle. FIG. 3 is a schematic diagram of the working principle of the mid-infrared gain medium in Embodiments 1 and 2 of the present invention. Referring to FIG. 3 , 11 is the incident pumping light, 12 is the photoinduced thermal carrier, 13 is the electron-hole pair, and 14 is the outgoing medium and long-wave infrared photon. The energy of the incident pump light 11 is several times of the forbidden band width of the gain material. After the gain material absorbs the pump photons, the electrons jump from the top of the valence band to the sub-level position of the top of the conduction band far beyond the bottom of the conduction band, generating photoinduced hot carriers12. Then the electron relaxes from the sub-level at the top of the conduction band, and the released energy allows other electrons to jump from the valence band to the bottom of the conduction band, generating multiple electron-hole pairs13. Then the multiple electron-hole pairs recombine and emit light, generating multiple mid- and long-wave infrared photons 14 .

What each embodiment in this specification focuses on is the difference from other embodiments, and the same and similar parts of the various embodiments can be referred to each other.

In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, there will be changes in specific implementation methods and application ranges. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. An infrared narrowband radiator, characterized in that, the infrared narrowband radiator comprises a substrate, a pumping light source, a first infrared resonant cavity, an infrared gain medium and a second infrared resonant cavity grown sequentially from bottom to top; The infrared narrowband radiator is used to generate medium and long wave infrared narrowband radiation of preset frequency v _IR ; The infrared gain medium is used to absorb the pump light emitted by the pump light source to generate medium and long-wave infrared light, and the frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR ; The forbidden band width of the infrared gain medium is equal to the energy of the medium and long-wave infrared light; the first infrared resonant cavity and the second infrared resonant cavity are both formed by stacking N resonant units from bottom to top, wherein N≥2; the first infrared resonant cavity and the second infrared resonant cavity are used to resonate and frequency-select the mid- and long-wave infrared light, so as to generate mid- and long-wave infrared narrowband radiation with a preset frequency _vIR . 2. a kind of infrared narrow-band radiator according to claim 1, is characterized in that, described infrared gain medium is the narrow bandgap semiconductor with multiple excitonic effect or the metalloid with multiple excitonic effect; The narrow bandgap semiconductor is one or more of PbSe nano quantum dots, PbS nano quantum dots, PbTe nano quantum dots, InAs nano quantum dots, InP nano quantum dots, CdSe nano quantum dots and CdTe nano quantum dots; The metalloid is one or more of Sn nano quantum dots, CdHgTe nano quantum dots, Ag ₂ S nano quantum dots, CuAg nano quantum dots, carbon nanotubes and graphene. 3. An infrared narrowband radiator according to claim 2, characterized in that the size range of each nano quantum dot is 1-1000 nm. 4. A kind of infrared narrowband radiator according to claim 1, is characterized in that, described first infrared resonant cavity and described second infrared resonant cavity are one-dimensional photonic crystals; The one-dimensional photonic crystal is a mid-to-long-wave infrared Bragg reflection grating or a mid-to-long-wave infrared distributed feedback grating; the resonant frequency of the one-dimensional photonic crystal is equal to the preset frequency v _IR . 5. A kind of infrared narrowband radiator according to claim 1, is characterized in that, described resonant unit comprises the first resonant layer and the second resonant layer that are arranged from bottom to top; The first resonant layer is one or more of MgF ₂ layers, CaF ₂ layers, BF ₂ layers, YF ₃ layers, SrF ₂ layers, KBr layers and ZnS layers, and the second resonant layer is Ge layer and One or more of the Si layers. 6. An infrared narrowband radiator, characterized in that, said infrared narrowband radiator comprises a substrate grown sequentially from bottom to top, a pump light source and an infrared resonant cavity doped with an infrared gain medium; said infrared narrowband radiation The device is used to generate medium and long-wave infrared narrow-band radiation with a predetermined frequency v _IR ; The infrared resonant cavity doped with an infrared gain medium is formed by stacking N resonant units doped with an infrared gain medium from bottom to top, wherein N≥2; the infrared resonant cavity doped with an infrared gain medium It is used to absorb the pump light emitted by the pumping light source to generate mid- and long-wave infrared light, and perform resonance frequency selection on the mid- and long-wave infrared light to generate mid- and long-wave infrared narrow-band radiation with a preset frequency v _IR ; the The frequency v _pump of the pump light and the preset frequency v _IR satisfy v _pump >2v _IR ; the forbidden band width of the infrared gain medium is equal to the energy of the medium and long-wave infrared light. 7. A kind of infrared narrowband radiator according to claim 6, is characterized in that, described infrared gain medium is the narrow bandgap semiconductor with multiple excitonic effect or the metalloid with multiple excitonic effect; The narrow bandgap semiconductor is one or more of PbSe nano quantum dots, PbS nano quantum dots, PbTe nano quantum dots, InAs nano quantum dots, InP nano quantum dots, CdSe nano quantum dots and CdTe nano quantum dots; The metalloid is one or more of Sn nano quantum dots, CdHgTe nano quantum dots, Ag ₂ S nano quantum dots, CuAg nano quantum dots, carbon nanotubes and graphene. 8. An infrared narrow-band radiator according to claim 7, characterized in that the size range of each nano quantum dot is 1-1000 nm. 9. A kind of infrared narrow-band radiator according to claim 6, characterized in that, the infrared resonant cavity doped with infrared gain medium is a one-dimensional photonic crystal; The one-dimensional photonic crystal is a mid-to-long-wave infrared Bragg reflection grating or a mid-to-long-wave infrared distributed feedback grating; the resonant frequency of the one-dimensional photonic crystal is equal to the preset frequency v _IR . 10. A kind of infrared narrow-band radiator according to claim 6, characterized in that, the resonant unit doped with an infrared gain medium comprises the first resonant layer doped with an infrared gain medium arranged from bottom to top and a second resonant layer doped with an infrared gain medium; The first resonant layer doped with infrared gain medium is MgF ₂ layer doped with infrared gain medium, CaF ₂ layer doped with infrared gain medium, BF ₂ layer doped with infrared gain medium, doped with One or more of the YF ₃ layer doped with the infrared gain medium, the SrF ₂ layer doped with the infrared gain medium, the KBr layer doped with the infrared gain medium, and the ZnS layer doped with the infrared gain medium, the second The resonance layer doped with the infrared gain medium is one or more of the Ge layer doped with the infrared gain medium and the Si layer doped with the infrared gain medium.