High energy disk laser thermal mirror effect control system

Abstract

The disclosure provides a large-energy disc laser thermal lens effect control system, comprising: a pump beam shaping system for outputting shaped pump laser; a disc crystal for generating large-energy laser under the excitation of the pump beam shaping system; a first detector for detecting the thermal distribution of the front surface of the disc crystal; a second detector for detecting the temperature change of the side surface of the disc crystal and / or the height change of the thermal expansion of the disc crystal and the thermal distribution of the side surface; wherein the first detector and the second detector are colloidal quantum dot mercury telluride infrared detectors, the first detector and the second detector are respectively connected with a control system, the control system adaptively regulates and controls the pump laser output by the pump beam shaping system based on the detection results of the first detector and the second detector, so as to control the thermal lens effect of the disc crystal, and further improve the optical performance of the large-energy disc laser.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of laser technology infrared imaging detector, in particular to a thermal lens effect control system of a high-energy disk laser. BACKGROUND

[0002] The application of solid-state laser systems with high output power, high efficiency and good beam quality has been popularized in industry and laboratory. Since Giesen et al. proposed the laser diode end-pumped disk TD (thin-disk) laser in 1993, it has further promoted the development of compact and efficient solid-state lasers. The composition thickness of the disk solid laser gain medium (disk crystal) is about 100-200 μm, which is much smaller than the radius of the gain medium. It is very easy to attach a heat sink system such as diamond, which has a compact optical structure, high optical-electrical conversion efficiency and extremely high heat dissipation efficiency. However, as the output power of the disk laser increases, the thin disk crystal in the high-energy disk laser will still change the refractive index of the disk due to heating, thermal expansion and thermal bending, resulting in thermal lens effect, which causes laser shift in the cavity and reduces the optical-electrical conversion efficiency of the laser. Therefore, solving the thermal lens effect of the disk crystal is one of the hot issues to break through the high-power and high-energy solid-state laser. The thermal infrared band covers the mid-infrared and long-infrared band, so an infrared detector with high performance and high precision is very important for measuring the thermal lens effect of the disk laser. Traditional infrared detectors are usually made of tellurium cadmium mercury, type II superlattice, indium antimonide and other bulk semiconductor materials, which need complex flip-chip bonding methods for synthesis, limiting the specifications, resolution and signal transmission of the detector. However, the emerging liquid nanometer semiconductor crystal (colloidal quantum dots CQD) has quantum confinement effect.

[0003] Therefore, the present application realizes direct silicon-based circuit board coupling integration by chemical solution synthesis, and the colloidal quantum dot detector has developed from a single-point detector to an imaging focal plane array, which can more accurately observe the thermal distribution and thermal change of the disk crystal surface in the disk laser. SUMMARY

[0004] The present disclosure aims to provide a thermal lens effect control system of a high-energy disk laser, which can solve at least one of the above technical problems. The specific scheme is as follows:

[0005] The present application provides a thermal lens effect control system of a high-energy disk laser, characterized in that it comprises:

[0006] A pump beam shaping system 5 is used to output shaped pump laser, and adjust the pump light to suppress the thermal lens effect of the disk crystal 3.

[0007] A disk crystal 3 generates high-energy laser under the excitation of the pump beam shaping system 5.

[0008] a first detector 10 for detecting the thermal distribution of the front surface of the disc crystal 3;

[0009] a second detector 20 for detecting the temperature change of the side surface of the disc crystal 3 and / or the height change of the disc crystal 3 due to thermal expansion and the thermal distribution of the side surface;

[0010] The first detector 10 and the second detector 20 are colloidal quantum dot mercury telluride infrared detectors, and the first detector 10 and the second detector 20 are respectively connected with a control system 4. The control system 4 adaptively regulates and controls the pump laser output by the pump beam shaping system 5 based on the detection results of the first detector 10 and the second detector 20, so as to control the thermal lens effect of the disc crystal 3.

[0011] In some embodiments, the colloidal quantum dot mercury telluride infrared detector comprises, in sequence: a substrate layer 11, a transparent conductive electrode layer 12, an electron transport layer 13, a mercury telluride quantum dot layer 14, a hole transport layer 15, a metal electrode layer 16, and a packaging layer 17.

[0012] In some embodiments, the substrate layer 11 is a glass substrate, which provides mechanical support and stability.

[0013] The transparent conductive electrode layer 12 is an indium tin oxide (ITO) conductive electrode layer, which serves as an electrode, allows photons to pass through, and collects electrons.

[0014] The electron transport layer 13 is a barium titanate electron transport layer, which is used for efficient electron transport.

[0015] The mercury telluride quantum dot layer 14 is a HgCl2-doped mercury telluride colloidal quantum dot layer, which is used for core light absorption and carrier generation.

[0016] The hole transport layer 15 is an indium tungstate hole transport layer, which is used for efficient hole transport.

[0017] The metal electrode layer 16 is an Au electrode layer, which serves as another electrode, forms a closed circuit, and collects holes.

[0018] In some embodiments, the imaging focal plane array of the colloidal quantum dot mercury telluride infrared detector is 1280×1024, which is configured to achieve 4×10 10 Jones average peak specific detectivity.

[0019] In some embodiments, the pump beam shaping system 5 comprises:

[0020] A laser diode pump light source 54 for outputting pump laser;

[0021] a first Fourier transform lens 53 for adjusting the pump laser into a frequency domain space;

[0022] a spatial light modulator 52 for adjusting the phase and amplitude of the pump laser in the frequency domain space;

[0023] a second Fourier transform lens 51 for adjusting the pump laser in the frequency domain space into a real domain space.

[0024] In some embodiments, the colloidal quantum dot mercury telluride infrared detector and the pump beam shaping system 5 form an adaptive system to achieve high-precision measurement of the thermal lens effect on the surface of the disc crystal 3, and further modulate the pump beam to suppress the focal length generated by the thermal lens effect.

[0025] In some embodiments, the equation of the refractive index of the disc crystal 3 changes with temperature is:

[0026]

[0027] where T0(x, y, z) is the temperature of the disc crystal 3 before pumping, T(x, y, z) is the dynamic temperature of the disc crystal 3 after pumping out light, is the thermal change coefficient of the refractive index of the disc crystal 3.

[0028] In some embodiments, the thermal focal length of the disc crystal 3 satisfies the following relationship:

[0029]

[0030] where P is the absorbed heat power, K(T) is the thermal conductivity of the disc crystal 3 with temperature change, w is the beam waist radius of the pump laser, α is the absorption coefficient, and L is the thickness of the disc crystal 3.

[0031] In some embodiments, the thermal change coefficient of the refractive index of the disc crystal 3 is 9×10 -6 K -1 .

[0032] In some embodiments, the thickness of the disc crystal 3 is 100-200 μm.

[0033] In some embodiments, the colloidal quantum dot mercury telluride infrared detector is formed by the following method:

[0034] Dissolve the inorganic mercury salt and elemental tellurium required for quantum dot synthesis into oleylamine as the reaction solvent; put the mixed solution into a glass bottle and heat on a hot plate, after the temperature of the hot plate reaches 100℃, inject triphenylphosphine using a pipette;

[0035] Using a pipette to add beta-mercaptoethanol to mercury telluride quantum dots, ultrasonic for 1 minute to take out the lower liquid;

[0036] Transferring mercury telluride quantum dots from a non-polar solvent to a polar solvent;

[0037] Controlling the polarity of quantum dots, doping by liquid phase method, introducing electrons or holes, adding HgCl2 or (NH4)2S to the intrinsic quantum dot solution to prepare n-type and / or p-type mercury telluride quantum dots.

[0038] In some embodiments, the polar solvent is a dimethylformamide solution.

[0039] The above scheme of the embodiments of the present disclosure has at least the following beneficial effects compared with the prior art:

[0040] The mercury telluride quantum dot detector in the present application has high device resolution, wide spectral regulation range, high average peak ratio detection rate, high preparation technology conversion efficiency, low cost, and small minimum noise equivalent temperature difference, and is suitable for monitoring the thermal mirror effect of the gain medium or the disc crystal in the disc laser. The colloidal quantum dot mercury telluride infrared detector made by the liquid phase synthesis chemical method can efficiently observe the thermal mirror effect change of the disc crystal in the disc laser.

[0041] The system is equipped with a pump wavefront shaping system and a mercury telluride quantum dot detector to form a self-adaptive combination. Through the mercury telluride quantum dot detector and the pump wavefront shaping, the detected data is fed back to the pump light shaping system, the pump light is adjusted to achieve the suppression effect of the disc crystal, and a high-precision measurement and suppression system of the thermal mirror effect of the gain medium of the large-energy disc laser is realized. The disc gain medium is the key to generating high-quality beams in the disc laser, so the manufacturing process of the large-energy disc laser can be further improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] The drawings incorporated into the specification and forming a part thereof, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained from these drawings without creative labor for those skilled in the art. In the drawings:

[0043] Figure 1 is a structural schematic diagram of a large-energy disc laser thermal mirror effect control system.

[0044] Figure 2 is a structural distribution of a colloidal quantum dot mercury telluride infrared detector device.

[0045] Figure 3The spectrum response of the colloidal quantum dot mercury telluride infrared detector. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the present application clearer, the following further describes the present application in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of the present application.

[0047] The terms used in the embodiments of the present application are only for the purpose of describing particular embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0048] It should be understood that the term "and / or" used herein only describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0049] Depending on the context, the word "if" as used herein can be interpreted as meaning "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (a stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detecting (a stated condition or event)" or "in response to detecting (a stated condition or event)".

[0050] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such product or system. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of another identical element in the product or system including the element.

[0051] The optional embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0052] The present application provides a large-energy disc laser hot mirror effect control system, comprising: a pump beam shaping system 5, a disc crystal 3, a first detector 10 and a second detector 20.

[0053] Specifically, in the embodiment, the pump beam shaping system 5 is used to output the shaped pump laser, and the pump light is adjusted to achieve the suppression of the thermal lens effect of the disc crystal 3. The pump light shaping system includes a plurality of pump source assemblies, which are parallel to the disc crystal 3 respectively. The pump light assembly is used for shaping the pump laser. The shaped pump light is perpendicular to the disc crystal 3, which is beneficial to the absorption of the pump laser by the disc laser.

[0054] Specifically, in the embodiment, the disc crystal 3 generates a large-energy laser under the excitation of the pump beam shaping system 5. The disc crystal has a thickness of 100-200 μm, which is much smaller than the radius of the gain medium. It is very easy to be attached to the heat sink system 2 such as diamond, and has a compact optical structure, high photoelectric conversion efficiency and high heat dissipation efficiency. With the increase of the output power of the disc laser, the extremely thin disc in the large-energy disc laser will change the refractive index of the disc due to heating, thermal expansion and thermal bending, produce thermal lens effect, make the laser in the cavity shift and the photoelectric conversion efficiency of the laser decrease. Through the adaptive combination of the pump wavefront shaping system and the mercury telluride quantum dot detector, the pump light is adjusted to achieve the suppression effect of the disc crystal.

[0055] Specifically, in the embodiment, the first detector 10 is used to detect the heat distribution of the front surface of the disc crystal 3, and feed back the detected heat distribution map to the computer control system 4 for monitoring the surface temperature of the disc crystal 3. The second detector 20 is used to detect the temperature change of the side surface of the disc crystal 3 and / or the height change of the thermal expansion of the disc crystal 3 and the heat distribution of the side surface of the disc crystal 3. The first detector 10 and the second detector 20 work simultaneously, feed back the measured heat distribution map and the focal length change of the crystal caused by the thermal lens effect to the computer control system 4, and the control system guides the pump light shaping 5 to output the pump light beam, and realizes the regulation of different heat distribution.

[0056] In the embodiment, the first detector 10 and the second detector 20 are colloidal quantum dot mercury telluride infrared detectors, and the first detector 10 and the second detector 20 are connected with the control system 4 respectively. The control system 4 adaptively regulates the pump laser output by the pump light beam shaping system 5 based on the detection results of the first detector 10 and the second detector 20, so as to control the thermal lens effect of the disc crystal 3, and realize the real-time thermal monitoring and thermal lens effect regulation of the disc crystal in the large-energy disc laser.

[0057] In the embodiment, the pump beam shaping system 5 comprises: a laser diode pump light source 54 for outputting pump laser; a first Fourier transform lens 53 for adjusting the pump laser into a frequency domain space; a spatial light modulator 52 for adjusting the phase and amplitude of the pump laser in the frequency domain space; and a second Fourier transform lens 51 for adjusting the pump laser in the frequency domain space into a real domain space.

[0058] The pump light shaping system 5 first performs Fourier transform through the first Fourier transform lens 53 to convert the beam in the real domain space into the frequency domain space (Fourier space). In the Fourier space, the spatial frequency information of the beam is explicitly separated, which facilitates accurate modulation. In the frequency domain space, the spatial light modulator 52 can control the interference and diffraction characteristics of the beam in the real domain space by adjusting the phase of each pixel point, so as to change the focusing and shape of the beam. By controlling the transmittance of each region, the intensity distribution of the beam in different regions is adjusted, which further affects the overall shape and mode of the beam. Then, the second Fourier transform lens 51 is used to convert it into the real domain space. This modulation can convert the original fundamental mode Gaussian beam TEM 00 into high-order mode TEM nn (n represents different order modes, and the adjustment range is 0-6), so as to change the energy distribution of the beam, optimize the heat distribution, and thereby suppress the focal length f generated by the thermal lens effect.

[0059] In the embodiment, the equation of the refractive index of the disc crystal 3 changing with temperature is:

[0060]

[0061] wherein T0(x, y, z) is the temperature of the disc crystal 3 before pumping, T(x, y, z) is the dynamic temperature of the disc crystal 3 after pumping out light, is the thermal change coefficient of the refractive index of the disc crystal 3.

[0062] Further, the change of the refractive index of the disc crystal 3 and the thermal expansion of the thickness can generate an optical path difference OPD along the z direction of the paraxial direction, and the relationship is as follows:

[0063] OPD = ∫Δn(x, y, z)dz

[0064] Further, according to the diffraction theory of scalar field, the optical path difference OPD caused by thermal effect is regarded as the phase of the lens in geometric optics, and the thermal focal length of the disc crystal 3 satisfies the following relationship:

[0065]

[0066] Where P is the absorbed thermal power, K(T) is the thermal conductivity of the disk crystal 3 as a function of temperature, w is the beam waist radius of the pump laser, α is the absorption coefficient, and L is the thickness of the disk crystal 3.

[0067] Furthermore, the coefficient of thermal change of the refractive index of the disc crystal 3 is 9 × 10⁻⁶. -6 K -1 .

[0068] In some embodiments, such as Figure 2 As shown, the colloidal quantum dot mercury telluride infrared detector comprises, in sequence: a substrate layer 11, a transparent conductive electrode layer 12, an electron transport layer 13, a mercury telluride quantum dot layer 14, a hole transport layer 15, a metal electrode layer 16, and an encapsulation layer 17.

[0069] Specifically, in this embodiment, the substrate layer 11 is a glass substrate, which provides mechanical support and stability;

[0070] The transparent conductive electrode layer 12 is an indium tin oxide (ITO) conductive electrode layer, which serves as an electrode to allow photons to pass through and collect electrons.

[0071] The electron transport layer 13 is a barium titanate electron transport layer, which is used to efficiently transport electrons, block holes, and reduce recombination.

[0072] The mercury telluride quantum dot layer 14 is a HgCl2-doped mercury telluride colloidal quantum dot layer, which is used for the absorption of core light and the generation of charge carriers, and determines the photoelectric performance of the device.

[0073] The hole transport layer 15 is an indium tungstate hole transport layer, which is used to efficiently transport holes, block electrons, and reduce electron-hole recombination.

[0074] The metal electrode layer 16 is an Au electrode layer, which serves as another electrode to form a closed circuit and collect holes.

[0075] The encapsulation layer 17 is an epoxy resin encapsulation layer, used to protect the device, extend the device's lifespan, and maintain the stable performance of the colloidal quantum dot mercury telluride infrared detector.

[0076] Specifically, in this embodiment, the colloidal quantum dot mercury telluride infrared detector is used to convert light signals into heat signals and transmit them to the computer control system 4 to accurately display the surface temperature of the disc crystal 3.

[0077] Specifically, in this embodiment, the imaging focal plane array of the colloidal quantum dot mercury telluride infrared detector is 1280×1024, configured to achieve 4×10 in the 4.6μm band. 10The average peak ratio detection rate, high resolution, high average peak ratio detection rate and low noise equivalent temperature difference of the Jones can more accurately observe the thermal distribution and change of the disc crystal surface, and realize the thermal mirror effect monitoring of the gain medium in the laser or the disc crystal in the disc laser.

[0078] Specifically, in the embodiment, the colloidal quantum dot mercury telluride infrared detector is formed by the following method:

[0079] Dissolve the inorganic mercury salt and elemental tellurium required for quantum dot synthesis into oleylamine as a reaction solvent; weigh the required inorganic mercury salt HgCl2 and elemental tellurium, and dissolve them in oleylamine. In an anhydrous and oxygen-free glove box, use a magnetic stirrer to heat to 120°C, continuously stir until all the solids are completely dissolved, and form a uniform mixed solution.

[0080] Put the mixed solution into a glass bottle and heat on a hot plate, slowly heat to 100°C under argon protection, after the hot plate temperature reaches 100°C, keep for 30 minutes to ensure the uniformity of the solution, use an anhydrous and oxygen-free pipette to slowly inject triphenylphosphine. The injection rate needs to be controlled at 1 milliliter per minute to ensure the stable growth and size uniformity of the quantum dots. According to the emission wavelength of the required quantum dots, accurately control the reaction temperature and time, high temperature and long reaction time will cause the size of the quantum dots to increase, and the emission wavelength to red shift. The practical temperature control system accurately adjusts the reaction temperature, and the growth of the quantum dots can be observed by infrared spectroscopy or other online monitoring methods.

[0081] Further, in order to realize the doping of mercury telluride quantum dots, ligand exchange needs to be performed, and the specific steps are as follows:

[0082] Use a pipette to add β-mercaptoethanol to the mercury telluride quantum dots, ultrasonic for 1 minute to remove the lower liquid, and realize the doping of the mercury telluride quantum dots by the mixed liquid phase ligand exchange method.

[0083] Transfer the mercury telluride quantum dots from a non-polar solvent to a polar solvent;

[0084] Control the polarity of the quantum dots, dope by liquid phase method, introduce electrons or holes, add HgCl2 or (NH4)2S to the intrinsic quantum dot solution to prepare n-type and / or p-type mercury telluride quantum dots. The device resolution of the mercury telluride quantum dot (HgTe CQDs) detector is high, the average peak ratio detection rate is high, and the lowest noise equivalent temperature difference is small, which is suitable for monitoring the thermal mirror effect of the gain medium in the laser or the disc crystal in the disc laser. It solves the defects of complex flip-chip bonding method of traditional infrared detector, limited specifications, resolution and signal transmission of the detector.

[0085] In the embodiment, the polar solvent is dimethylformamide solution.

[0086] The structure of the prepared shaped colloidal quantum dot mercury telluride detector is shown in Figure 2 The electrons are transported to the transparent conductive electrode through the ETL, while the holes are transported to the metal electrode through the HTL, forming a current signal. By measuring the current change, the intensity and wavelength of the incident light can be detected, realizing the photoelectric detection function. The spectral response of the prepared colloidal quantum dot mercury telluride detector at room temperature is shown in Figure 3 The results show that the colloidal quantum dot mercury telluride detector realizes a 4×10 10 The average peak ratio detection rate of Jones can more accurately observe the thermal distribution of the disc crystal surface in the disc laser. The controlled pump light shaping system and the high-precision colloidal quantum dot mercury telluride detector form an adaptive system, which can realize real-time thermal monitoring and thermal lens effect regulation of the disc crystal in the large-energy disc laser.

[0087] The following is a specific embodiment of preparing a colloidal quantum dot mercury telluride (HgTe) detector. The entire process needs to be carried out under anhydrous and anaerobic conditions to ensure the quality and performance of the quantum dots.

[0088] Material preparation:

[0089] ① Mercury telluride (HgTe) precursor (inorganic precursor): mercury chloride (HgCl2): 0.1 moles (about 22.2 grams); 0.1 moles (about 125.6 grams).

[0090] ② Solvents and ligands: oleylamine (OA) as the reaction solvent: 50 milliliters; tri-n-octylphosphine (TOP) as the injection agent: 10 milliliters; β-mercaptoethanol (β-ME) as the ligand displacement agent: 5 milliliters; dimethylformamide (DMF) as the polar solvent: 100 milliliters.

[0091] ③ Doping reagents: mercury chloride (HgCl2): for preparing n-type quantum dots, 0.005 moles (about 1.11 grams); ammonium thiocyanate ((NH4)2S): for preparing p-type quantum dots, 0.005 moles (about 0.195 grams).

[0092] Equipment preparation:

[0093] ① Anhydrous and anaerobic operation device (such as a glove box under argon or nitrogen protection)

[0094] ② High-purity glass reaction bottle (100 milliliter capacity)

[0095] ③ Hot plate and temperature control system

[0096] (iv) Pipette (water-free type)

[0097] (v) Ultrasonic cleaner

[0098] (vi) Separatory funnel

[0099] Preparation steps:

[0100] 1. Precursor dissolution

[0101] The required 0.1 mole of inorganic mercury salt HgCl2(approximately 22.2 grams) and 0.1 mole of elemental tellurium (approximately 125.6 grams) were weighed and dissolved in 50 milliliters of oleylamine. In an anhydrous oxygen-free glovebox, a magnetic stirrer was used to heat to 120°C, and stirring was continued until all solids were completely dissolved, forming a uniform precursor solution.

[0102] 2. Heating reaction

[0103] The uniform precursor solution was transferred to a high-purity glass reaction bottle. The reaction bottle was placed on a heating magnetic stirrer, and slowly heated to 100°C under argon protection, and kept at this temperature for 30 minutes to ensure the uniformity of the solution.

[0104] 3. Injecting trioctylphosphine

[0105] Under the reaction conditions of 100°C, 10 milliliters of trioctylphosphine (TOP) was slowly injected using an anhydrous oxygen-free pipette. The injection rate was controlled at 1 milliliter per minute to ensure the stable growth and size uniformity of the quantum dots.

[0106] 4. Controlling reaction temperature and time

[0107] The temperature and time of the reaction were precisely controlled according to the emission wavelength of the desired quantum dots. Higher temperature and longer reaction time usually resulted in larger quantum dot size, and thus the emission wavelength moved towards the red direction. Lower temperature (100°C) and shorter reaction time (30 minutes) were maintained. The temperature was appropriately increased (to 150°C) and the reaction time was extended (1 hour). The reaction temperature was precisely adjusted using a temperature control system, and the growth of the quantum dots was observed by infrared spectroscopy or other online monitoring methods.

[0108] 5. Anhydrous oxygen-free environment

[0109] During the entire synthesis process, the reaction system was ensured to be carried out under argon or nitrogen protection, and all reaction containers were coated with anhydrous drying agents (such as molecular sieves) to prevent the introduction of moisture and oxygen. After the synthesis was completed, the reaction bottle was sealed and continued to cool to room temperature under an inert atmosphere.

[0110] 6. Ligand exchange

[0111] To dope the HgTe quantum dots, a ligand exchange step is required: Take the completed quantum dot solution and slowly add 5 mL of β-mercaptoethanol (β-ME). Sonicate for 1 minute at 60% power using an ultrasonic cleaner to facilitate the replacement of the oleylamine ligand. After centrifugation (8000 rpm for 10 minutes), carefully remove the supernatant to remove unreacted oleylamine and impurities. Add the supernatant to 100 mL of dimethylformamide (DMF) and mix thoroughly to transfer the quantum dots from a non-polar solvent to a polar solvent. Use a centrifuge (8000 rpm for 10 minutes) to separate the untransferred impurities and take the supernatant as the quantum dot solution in a polar solvent.

[0112] 7. Doping control

[0113] Dope the quantum dots by liquid phase method to introduce electrons or holes to produce n-type or p-type HgTe quantum dots:

[0114] ① Preparation of n-type quantum dots

[0115] In a DMF solution, slowly add 1.11 g of mercury chloride (HgCl2) while continuously stirring for 30 minutes to ensure uniform incorporation of mercury ions into the quantum dot lattice and provide additional electrons.

[0116] ② Preparation of p-type quantum dots

[0117] In another DMF solution, slowly add 0.195 g of ammonium thiocyanate ((NH4)2S) while continuously stirring for 30 minutes to incorporate sulfur ions into the quantum dot lattice and form holes.

[0118] 8. Post-processing and characterization

[0119] After centrifugation of the doped quantum dot solution (8000 rpm for 10 minutes), discard the supernatant and add fresh DMF for repeated washing, at least three times to remove unreacted reagents and byproducts. After washing, the quantum dots are precipitated in dry DMF and thoroughly dispersed to ensure uniformity.

Claims

1. A high energy disk laser hot mirror effect control system, characterized by, The system comprises: a pump beam shaping system (5) for outputting shaped pump laser; a disc-shaped crystal (3) for generating high-energy laser under the excitation of the pump beam shaping system (5); a first detector (10) for detecting the thermal distribution of the front surface of the disc-shaped crystal (3); a second detector (20) for detecting the temperature change of the side surface of the disc-shaped crystal (3) and / or the height change of the disc-shaped crystal (3) due to thermal expansion and the thermal distribution of the side surface; wherein the first detector (10) and the second detector (20) are colloidal quantum dot mercury telluride infrared detectors, and the first detector (10) and the second detector (20) are respectively connected with a control system (4), and the control system (4) adaptively regulates and controls the pump laser output by the pump beam shaping system (5) based on the detection results of the first detector (10) and the second detector (20), so as to control the thermal lens effect of the disc-shaped crystal (3); the pump beam shaping system (5) comprises: a laser diode pump source (54) for outputting pump laser; a first Fourier transform lens (53) for adjusting the pump laser into a frequency domain space; a spatial light modulator (52) for adjusting the phase and amplitude of the pump laser in the frequency domain space; a second Fourier transform lens (51) for adjusting the pump laser in the frequency domain space into a time domain space.

2. The thermal lens effect control system of the high-energy disc-shaped laser according to claim 1, wherein the colloidal quantum dot mercury telluride infrared detector comprises, in sequence: a substrate layer (11), a transparent conductive electrode layer (12), an electron transport layer (13), a mercury telluride quantum dot layer (14), a hole transport layer (15), a metal electrode layer (16), and a packaging layer (17).

3. The thermal lens effect control system of the high-energy disc-shaped laser according to claim 2, wherein the substrate layer (11) is a glass substrate, which provides mechanical support and stability; the transparent conductive electrode layer (12) is an indium tin oxide (ITO) conductive electrode layer, which serves as an electrode, allows photons to pass through and collects electrons; the electron transport layer (13) is a barium titanate electron transport layer, which is used for efficient electron transport; the mercury telluride quantum dot layer (14) is a HgCl2-doped mercury telluride colloidal quantum dot layer, which is used for core light absorption and carrier generation; the hole transport layer (15) is an indium tungstate hole transport layer, which is used for efficient hole transport; the metal electrode layer (16) is an Au electrode layer, which serves as another electrode, forms a closed circuit, and collects holes. The equation of the refractive index of the disc-shaped crystal (3) changing with temperature is: The thermal focal length of the disc-shaped crystal (3) satisfies the following relationship:

4. The high energy disk laser thermal mirror effect control system of claim 1, wherein, The imaging focal plane array of the colloidal quantum dot mercury telluride infrared detector is 1280x1024, which is configured to realize 4x10 10 The average peak specific detectivity of Jones.

5. The high energy disk laser thermal mirror effect control system of claim 1, wherein, K(T) ； wherein, T 0(x,y,z) is the temperature of the disc crystal (3) before pumping, T (x,y,z) is the dynamic temperature of the disc crystal (3) after pumping out light, is the thermal variation coefficient of the refractive index of the disc crystal (3).

6. The high energy disk laser thermal mirror effect control system of claim 5, wherein, The colloidal quantum dot mercury telluride infrared detector is formed by the following method: ； wherein P is the absorbed heat power, Dissolve the inorganic mercury salt and elemental tellurium required for quantum dot synthesis into oleylamine as a reaction solvent; place the mixed solution in a glass bottle and heat on a hot plate, and after the temperature of the hot plate reaches 100 °C, inject tri-octyl phosphine with a pipette; is the thermal conductivity of the disc crystal (3) as a function of temperature, w is the beam waist radius of the pump laser, is the absorption coefficient, L is the thickness of the disc crystal (3).

7. The high energy disk laser thermal mirror effect control system of claim 5, wherein, The coefficient of thermal change of the refractive index of the disc crystal (3) is 9x10 -6 K -1 .

8. The high energy disk laser thermal mirror effect control system of claim 1, wherein, ​ ​ Adding beta-mercaptoethanol into the mercury telluride quantum dots by using a pipette, and taking the lower liquid after ultrasonic treatment for 1 minute; Transferring the mercury telluride quantum dots from a non-polar solvent to a polar solvent; Controlling the polarity of the quantum dots, doping by using a liquid phase method, introducing electrons or holes, adding HgCl2 or (NH4)2S into the intrinsic quantum dot solution to prepare n-type and / or p-type mercury telluride quantum dots.

9. The high energy disk laser thermal mirror effect control system of claim 8, wherein, The polar solvent is a dimethylformamide solution.

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