116 results about "Diamond crystal" patented technology

The present invention provides a high temperature resistant inorganic glue, a preparation method, an application and a method for limiting the drift of CVD seed crystals. The high temperature resistant inorganic glue comprises: 100 to 400 parts by weight of aluminum silicate; 50 to 200 parts by weight of aluminum phosphate; 50 to 400 parts by weight of copper oxide-copper-titanium-diamond composite material or copper oxide-titanium-diamond composite material; 50 to 200 parts by weight of phosphoric acid; and 100 to 400 parts by weight of a dispersant. The method for limiting the drift of CVD diamond seed crystals is to apply a high temperature resistant inorganic glue on the bottom of the CVD diamond seed crystal before the chemical vapor deposition growth of the CVD diamond seed crystal, press it flat on a molybdenum sheet and solidify it. The high temperature resistant inorganic glue of the present invention can withstand temperatures above 1200°C and is easy to glue and remove; the CVD diamond seed crystal is bonded to the molybdenum sheet by the high temperature resistant inorganic glue, and the seed crystal drift is limited during chemical vapor deposition growth.

The invention belongs to the technical field of chemical vapor deposition of diamond films, and particularly relates to a high-temperature pulse bias assisted diamond single crystal heteroepitaxial growth method, which comprises the following steps: carrying out ultrasonic cleaning and etching pretreatment on an Ir / YSZ / Si composite substrate; self-assembling a polystyrene nanosphere template on the surface of the substrate; placing the substrate covered by the template in a low-power oxygen plasma etching machine for etching to form a regular nano pit array; putting the etched substrate into a microwave plasma chemical vapor deposition (MPCVD) reaction cavity, and applying-300V short pulse bias voltage to realize nucleation of high-density diamond crystal nuclei; after the bias voltage is closed, conventional diamond epitaxial growth continues to be carried out in the MPCVD cavity; after the growth is finished, the self-supporting diamond film is separated through chemical dissolution, a nano pit template is formed through pre-etching, and one-time-300V short pulse bias is combined, so that high-density and highly-uniform sp3 crystal nucleus nucleation can be realized on the surface of the substrate, and the distribution consistency and nucleation efficiency of diamond crystal nucleation are improved.

The invention provides an argon gas cluster ion polishing machine and a diamond crystal workpiece polishing method. The polishing machine comprises a pulse control valve used for generating pulse type airflow beams, and a nozzle device, a beam splitter, an ionizer, an absorption electrode, an accelerator and a permanent magnet which are sequentially arranged in the spraying direction of the pulse type airflow beams. The nozzle device is used for spraying pulse type airflow beams; wherein the pulse type airflow beam comprises divergent argon atom airflow and neutral cluster particle flow concentrated on a central shaft; the beam splitter is used for screening and separating neutral cluster particles and argon atoms in the pulse type airflow beam; the ionizer is used for ionizing the neutral cluster particles into cluster ions; the suction electrode is used for guiding the ionized ionomer clusters to form an initially converged conical airflow beam; the accelerator is used for focusing and accelerating the conical airflow beam; the permanent magnet is used for separating ions with different masses to form a pure cluster ion beam; and high-quality polishing of the surface of the diamond crystal workpiece can be achieved.

The invention provides a bionic gradient-based TPMS double-channel heat exchanger structure design method, which relates to the technical field of heat exchanger design, and comprises the following steps: S1, creating a cube reference model, determining the position of each node in the reference model according to the spatial topological relation of a diamond crystal structure, and carrying out three-dimensional space connection to form a diamond unit cell support structure; s2, parametric modeling of the multiple tubular objects is conducted through a curved surface tool according to the diamond unit cell support structure, and a tubular curved surface network is generated; s3, performing equidistant offset operation on the tubular curved surface network to obtain a TPMS unit cell structure; s4, performing three-dimensional array on the TPMS unit cell structure to obtain an HRD lattice structure model; and S5, carrying out gradient parameterization regulation and control on the diameter of the fluid channel of the HRD lattice structure model. The heat exchanger has the beneficial effects that unification of light weight and high rigidity is achieved, and the heat exchange efficiency can be remarkably improved while high rigidity and light weight are achieved.

The invention discloses a preparation method of a high-quality self-supporting polycrystalline diamond substrate. The preparation method comprises the following steps: obtaining a larger first substrate and a smaller second substrate; the molybdenum substrate is a polished molybdenum metal substrate; sowing diamond seed crystals on the first substrate by using an ultrasonic sowing method, and growing a nanocrystalline diamond epitaxial layer by using a CVD (Chemical Vapor Deposition) process; cutting the first substrate by using precise laser to obtain an annular polycrystalline diamond solid seed crystal of which the inner diameter is greater than that of the second substrate; placing a second substrate in the inner diameter of the second substrate, guiding generated tiny diamond grains to the second substrate through a boundary induction mechanism and applying direct current bias voltage, and uniformly wrapping the tiny diamond grains to form a self-supporting polycrystalline diamond substrate; according to the preparation method of the self-supporting polycrystalline diamond substrate, the orientation consistency and the crystallization quality of a diamond film are remarkably improved, and the prepared self-supporting polycrystalline diamond substrate has the advantages of being low in surface roughness, compact in structure, simplified in follow-up process and the like.

The invention provides a high-power blue-light solid laser for urinary surgery, which comprises a pumping source, a pumping cavity, an annular water cooling structure, a titanium-doped sapphire slice crystal, an end mirror, a diamond crystal, a focusing system, a frequency doubling crystal, a coupling system and an optical fiber, the pumping cavity is used for reflecting 532nm pumping laser so as to focus the 532nm pumping laser on the titanium-doped sapphire slice crystal; the titanium-doped sapphire slice crystal generates 803nm laser based on 532nm pumping laser; the diamond crystal enables 803nm laser to form 900nm laser through Raman frequency shift; the focusing system is used for focusing the 900nm laser into the frequency doubling crystal so as to convert the 900nm laser into 450nm blue laser through nonlinear frequency conversion; the coupling system couples the 450nm blue laser into the optical fiber to form a stable high-power 450nm blue laser light source which can be applied to urinary surgery. The blue light laser is simple in structure, the problems that an existing blue light laser is low in output power and poor in light beam quality are solved, and operation safety and efficiency are improved.

Method of automated spatial patterning of defect centers (6) in a substrate, particularly a diamond crystal lattice (50), comprising the following steps: - providing a defect center (6) distribution to a machine-learning model, the machine-learning model being particularly trained to determine an output for displacement of at least one defect center (6) based on the provided defect center (6) distribution, the machine learning model providing an output for displacement of individual defect centers (6), - particularly providing a substrate, particularly diamond, comprising defect centers (6) in a bulk structure of the substrate, particularly a bulk diamond crystal lattice (50), - detecting the position of at least one defect center (6) in the bulk structure of the substrate, particularly the bulk diamond crystal lattice (50), and - displacing (61) the at least one defect center (6) in the bulk structure of the substrate, particularly the bulk diamond crystal lattice (50), particularly site-specific, in a defined direction.

The invention discloses a design method for crystal face layout and grinding direction of a diamond biological slicing cutter, and relates to the technical field of ultra-precision machining. The method comprises the following steps of: representing the geometric shape of a cutter by adopting a surface patch, respectively taking three crystal orientations (100), (010) and (001) of a monocrystal diamond crystal as an x axis, a y axis and a z axis, and describing a geometric model of the cutter by giving spatial positions of important nodes; setting a characteristic space, and considering deflection angles of a cutter relative to three crystal orientations of the single crystal diamond and grinding angles on front and rear cutting surfaces; setting three optimization targets of machining efficiency, blade use strength and blade straightness; and executing a genetic algorithm to iteratively output a feasible cutter sharpening scheme. A feasible crystal face layout and a grinding direction are tested based on an NSGA-II multi-target genetic algorithm, a surface patch is adopted to represent the geometrical shape of a tool, three optimization targets of machining efficiency, cutting edge strength and cutting edge straightness are comprehensively considered, and an optimal layout scheme is obtained through screening iteration.

The application relates to a deposition chamber structure and an MPCVD device, and belongs to the field of diamond synthesis devices. The technical scheme is as follows: a deposition chamber structure comprises a base, a tubular quartz window is fixedly arranged on the base, an upper cover is sealingly connected above the quartz window, a metal ring is arranged outside the quartz window, a plurality of horizontally arranged and vertically arranged microwave feeding slits are arranged in the middle region of the metal ring, a resonant metal cavity is arranged outside the middle region of the metal ring, the resonant metal cavity is used for being connected with a microwave source, a growth base capable of multi-stage lifting is arranged in the quartz window, the dimension of microwave feeding is increased, a discharge area is coupled above the growth base to form a plasma with the characteristics of large size, uniform stability and high energy density, the growth base can be lifted in multiple stages, the deposition quality of a growth sample is optimized, the deposition area of the growth sample is expanded, and preparation of a high-quality large-size diamond crystal is realized.

The utility model discloses a cleaning device for diamond crystals, and relates to the technical field of diamond machining. The screening device comprises a box body, a feeding mechanism and a cleaning and overturning mechanism are arranged in the box body, and two matched screening mechanisms are arranged in the box body; the screening mechanism comprises two fixing frames arranged in the box body, each fixing frame is provided with two elastic pieces, and a screening plate is arranged at one ends of the multiple elastic pieces. By means of the rotating rod, the cam sleeve can drive the material screening plate to continuously move upwards under the driving of the transmission mechanism, the material screening plate can be driven to rapidly move downwards after rising through the pressure of the rotating rod under the arrangement of the elastic piece, and the material screening plate and the elastic piece are matched for use, so that the material screening efficiency is improved. According to the diamond screening device, the screening plate can be rapidly vibrated, so that the situation that diamonds on the screening plate are accumulated during filtering can be avoided, and the diamond cleaning efficiency is improved.

The invention discloses a low-loss preparation method of a single crystal diamond wafer. The low-loss preparation method comprises the following steps: A, carrying out laser ablation on the surface of a single crystal diamond crystal ingot; b, performing laser-assisted polishing on the surface; c, the ultrafast pulse laser is modulated into N modified light spots, all the modified light spots are made to scan at the corresponding depth positions according to a preset path at the same time, and a scanning face formed by the same modified light spot covers the cross section of the single crystal diamond crystal ingot in the 100 crystal face direction, n laser modified layers distributed in the direction perpendicular to the 100 crystal face in the single crystal diamond crystal ingot are formed after scanning; d, performing stress-induced separation on the monocrystal diamond crystal ingot; e, performing laser ablation on the cutting surface of the single crystal diamond wafer; and F, the cutting face is subjected to laser-assisted polishing. According to the low-loss preparation method of the single-crystal diamond wafer, the material loss of the single-crystal diamond crystal ingot can be reduced, and the wafer yield of the single-crystal diamond crystal ingot can be increased.

The present invention proposes a multimode laser frequency comb device and a degenerate multimode control method. The device includes a diamond crystal, an optical frequency degeneration module, and a degeneracy control module. Based on the multimode laser frequency comb device, the present invention applies stress to the diamond crystal according to the degenerate multimode control method, regulating the lattice constant of the diamond crystal, thereby regulating the degeneracy of Raman vibrations and controlling the optical frequency degeneration mode. This converts an existing single-mode laser comb into a multimode laser comb output. This can generate a multimode optical frequency comb consisting of a single mode or multiple single-mode frequency combs with spectral width spacing. This multimode optical frequency comb has the advantages of wide wavelength coverage, large spectral spacing, and multiple spectral width spacings that are tunable.

The invention discloses a preparation method of a large-size diamond-based gallium nitride wafer, and belongs to the technical field of semiconductor materials. The method comprises the steps that gallium nitride wafers are separately placed in grooves of a diamond deposition tray for diamond deposition, the diamond nucleation process on the surface of gallium nitride is creatively designed, it is guaranteed that diamond crystal nuclei stably and orderly grow on the surface of the gallium nitride wafers, and a foundation is laid for subsequent stable and orderly deposition of a diamond substrate. According to the method, the problems of wafer warping, wafer fragmentation, diamond and gallium nitride stripping and the like caused by mismatching of thermal expansion coefficients of diamond and gallium nitride are solved, the thermal mismatching rate is reduced, and the bonding stability and the interface thermal conductivity between the gallium nitride wafer and the diamond substrate are improved.

The present invention belongs to the field of polishing equipment, and specifically provides a polishing equipment for diamond crystals and a polishing method thereof, wherein the polishing equipment for diamond crystals comprises: a support frame; a rotating table, which is rotatably arranged on the support frame, and a plurality of concentrically arranged annular liquid storage tanks are provided on the top surface of the rotating table; a driving mechanism, which is arranged on the support frame and used to drive the rotating table to rotate; and a polishing cloth, which is arranged on the rotating table and used for chamfering and polishing the diamond crystal. By arranging a plurality of concentrically arranged annular liquid storage tanks on the top surface of the rotating table, when the rotating table rotates, the polishing liquid in the annular liquid storage tanks splashes outward under the action of centrifugal force, thereby continuously infiltrating the polishing cloth facing the annular liquid storage tanks, maintaining sufficient water in the polishing cloth, thereby avoiding the phenomenon of crystallization of the polishing liquid in the polishing cloth. At the same time, the utilization efficiency of the polishing liquid is improved, the waste of the polishing liquid is reduced, and the cost of polishing is reduced.

The invention provides a multi-mode laser optical frequency comb device and a degeneracy degeneration multi-mode control method. The device comprises a diamond crystal, an optical frequency sparse generation module and a degeneracy control module. According to the embodiment of the invention, based on the multi-mode laser optical frequency comb device, stress is applied to the diamond crystal and the lattice constant of the diamond crystal is regulated and controlled according to a degenerate and degenerate multi-mode control method, so that the degeneracy of Raman vibration is regulated and controlled, the optical frequency sparse mode is controlled, and the existing single-mode laser optical comb is regulated into the multi-mode laser optical comb for output; the multi-mode optical frequency comb formed by the single-mode optical frequency comb capable of generating a single mode or a plurality of spectral width intervals has the advantages of being wide in wavelength coverage range, large in spectral interval, capable of generating a plurality of spectral width intervals and tunable in spectral width interval.

The invention relates to a sensor element (1), comprising: a crystal with colour centres, in particular a diamond crystal (2) with NV centres (7). The sensor element (1) has a lens (3) on which the crystal is fixed, wherein the lens (3) has an orientation aid (5) for fixing the crystal to the lens (3) with a predefined orientation, and wherein the lens (3) is transmissive for excitation light (9) for exciting the colour centres, in particular the NV centres (7), and / or is transmissive for fluorescent light (6) which is generated during the excitation of the colour centres, in particular the NV centres (7). The invention also relates to an optical sensor, in particular a magnetometer (12), comprising: a sensor element (1) which is designed as described above, and a magnetic field generator (14) for generating an offset magnetic field (B0) in the region of the crystal, preferably in the region of the diamond crystal (2), wherein the offset magnetic field (B0) is oriented along a magnetic field axis (15).

The invention provides substrate table system MPCVD equipment. The substrate table system MPCVD equipment comprises a microwave reflection table and a large molybdenum table which are arranged in a stacked mode. The substrate table is arranged on one side, far away from the microwave reflection table, of the large molybdenum table; wherein one side, far away from the microwave reflecting table, of the large molybdenum table is provided with an annular bulge, and the annular bulge is coaxial with the substrate table and surrounds the periphery of the substrate table. By means of the arrangement, the annular boss is arranged on the periphery of the substrate table, plasma formed above the substrate table can be evenly distributed, the temperature difference between the center and the edge is further reduced, it is guaranteed that the diamond growth rate is consistent, the stress of diamond crystals is reduced, and the cracking rate is reduced.

A quantum device according to the present invention comprises a first diamond crystal layer that has a first center point and is shaped to extend in four mutually orthogonal directions from the first center point, a second diamond crystal layer that has a second center point and is shaped to extend in four mutually orthogonal directions from the second center point, and a color center that is on one of the first diamond crystal layer and the second diamond crystal layer. The first diamond crystal layer and the second diamond crystal layer comprise a quantum bit element that is layered such that at least a portion of the first center point and the second center point overlap, a first optical waveguide that is connected to each of four first end parts of the first diamond crystal layer, and a second optical waveguide that is connected to each of four second end parts of the second diamond crystal layer.　

The present invention provides a diamond crystal growth device, which belongs to the field of diamond growth technology and solves the problem of poor diamond growth quality in the prior art. The present invention includes a first cavity, a growth zone is provided below the first cavity, and the growth zone is used to grow diamonds; an antenna, the antenna is arranged in the first cavity and located above the growth zone, and the antenna is used to excite the reaction gas to form plasma; and an adjustment component, the adjustment component includes an adjustment ring and a driving member, the adjustment ring is movably arranged above the antenna, the adjustment ring is used to constrain the shape of the plasma, and the driving member acts on the adjustment ring so that the adjustment ring has at least horizontal freedom of movement. The present application configures an additional adjustment component, uses the adjustment ring to constrain the shape of the plasma, and then adjusts the horizontal position of the adjustment ring through the driving member, thereby indirectly adjusting the horizontal position of the plasma, thereby achieving plasma position correction, and then improving the quality of diamond crystal growth.

The invention discloses a narrow-linewidth tunable Raman laser and an emission method, and relates to the field of Raman lasers, the narrow-linewidth tunable Raman laser comprises a half-wave plate, a pumping source and a focusing lens, the pumping source and the focusing lens are respectively arranged on two sides of the half-wave plate, and a laser resonant cavity is arranged on the other side of the focusing lens. A laser resonant cavity is arranged on one side of the laser cavity, a lock cavity frequency multiplier is arranged on the other side of the laser resonant cavity, a shaping lens group is arranged between the laser resonant cavity and the lock cavity frequency multiplier, a dichroic mirror is arranged on the other side of the lock cavity frequency multiplier, and the laser resonant cavity is of a V-shaped cavity structure formed by an input mirror, an output mirror and a reflective blazed grating. A diamond crystal is arranged between the input mirror and the output mirror, the reflection type blazed grating is arranged below the diamond crystal, the stability of the laser resonant cavity is improved through the design of the reflector in the cavity, wavelength adjustment accurate to 0.01 nm is achieved, and loss in the transmission process is reduced through the cavity locking frequency multiplier of an annular cavity structure.

Provided are a substrate for epitaxially growing a diamond crystal, having at least a surface made of a metal, in which the above surface made of the metal is a plane having an off angle φ of more than 0°, and the full width at half maximum of the X-ray diffraction peak from the (002) plane by the X-ray rocking curve measurement at the above surface made of the metal is 300 seconds or less; and a method of manufacturing a diamond crystal, including epitaxially growing a diamond crystal on the above surface made of the metal of the above substrate.

The invention provides a diamond surface quality online sorting method and system for MPCVD, relates to the technical field of diamond growth monitoring, is applied to MPCVD equipment, and the MPCVD equipment is used for generating diamond crystals. Preprocessing the original image to obtain a preprocessed image; s2, extracting and processing the preprocessed image through multi-dimensional surface features to respectively obtain texture features, light intensity distribution features and geometric morphology features of the diamond; s3, a quality evaluation model is constructed and used for inputting texture features, light intensity distribution features and geometric morphology features of the diamond and outputting a diamond surface quality detection result, online real-time monitoring of the surface quality in the MPCVD diamond growth process is achieved, a traditional off-line detection mode is broken through, and the quality of the diamond is evaluated. The problem that the surface defect of the crystal cannot be dynamically tracked within a hundreds of hours of growth cycle is solved.

Method (20) for displacing defect centers (6) in a substrate for quantum applications in a defined direction, the method comprising the following steps - in particular providing a substrate, in particular diamond, which comprises defect centers (6) in a bulk substrate structure, in particular a massive diamond crystal lattice (50), - detecting the position of at least one defect center (6) in the bulk substrate structure, in particular the massive diamond crystal lattice (50), and - Displacing (61) the at least one defect center (6) in the volume substrate structure, in particular the massive diamond crystal lattice (50), in particular in a location-specific manner, in a defined direction.

The invention discloses a deposition chamber structure and MPCVD equipment, and belongs to the field of diamond synthesis equipment. According to the technical scheme, the deposition chamber structure comprises a base, a tubular quartz window is fixedly arranged on the base, an upper cover is connected to the upper portion of the quartz window in a sealed mode, a metal ring is arranged on the outer side of the quartz window in a sleeving mode, and a plurality of transversely-arranged and vertically-arranged microwave feed-in gaps are formed in the middle area of the metal ring; the outer side of the middle area of the metal ring is sleeved with a resonance metal cavity, the resonance metal cavity is used for being connected with a microwave source, a growth base table capable of lifting in a multi-stage mode is arranged in the quartz window, the microwave feed-in dimension is increased, and plasma which is large in discharge area, uniform, stable and high in energy density is formed above the growth base table in a coupling mode. And the growth base table can be lifted in a multi-stage manner, so that the deposition quality of the growth sample is optimized, the deposition area of the growth sample is expanded, and the preparation of the high-quality large-size diamond crystal is realized.

Provided in the present disclosure are a substrate stage system and an MPCVD apparatus. The substrate stage system comprises a microwave reflection stage and a large molybdenum stage, which are arranged in a stacked manner; and a substrate stage, which is arranged on the side of the large molybdenum stage away from the microwave reflection stage, wherein an annular boss is arranged on the side of the large molybdenum stage away from the microwave reflection stage, and the annular boss is coaxially arranged with the substrate stage and surrounds the periphery of the substrate stage. In this way, by means of the arrangement of the annular boss on the periphery of the substrate stage, plasma formed above the substrate stage can be relatively uniformly distributed, such that the temperature difference between the center and the edge is reduced so as to ensure that the diamond growth rate is consistent, thereby reducing the diamond crystal stress and thus also reducing the splitting rate.

The invention provides a preparation method of a self-supporting substrate for uniform growth of diamond, and relates to the field of diamond crystal growth. The method comprises the following steps: 1) growing a special diamond layer and a self-supporting diamond layer to obtain a self-supporting diamond substrate; (2) plasma etching is conducted on the back face of the self-supporting diamond substrate; (3) polishing the growth surface of the self-supporting diamond substrate; the method comprises the steps of (1) preparing a base with a rough layer surface, (2) preparing a back surface of the self-supporting diamond substrate, (3) preparing a rough layer surface of the base, (4) taking the base with the rough layer surface, and placing the back surface of the self-supporting diamond substrate on the rough layer surface of the base, and (5) carrying out compression joint on the self-supporting diamond substrate and the base to obtain the self-supporting substrate.The self-supporting substrate provided by the invention is beneficial to realizing heat distribution of a uniform interface.

The application discloses a narrow linewidth tunable Raman laser and an emission method, relates to the field of Raman lasers, and comprises a half-wave plate, a pump source and a focusing lens which are arranged on the two sides of the half-wave plate, a laser resonant cavity is arranged on the other side of the focusing lens, a cavity locking frequency doubler is arranged on the other side of the laser resonant cavity, a shaping lens group is arranged between the laser resonant cavity and the cavity locking frequency doubler, a dichroic mirror is arranged on the other side of the cavity locking frequency doubler, the laser resonant cavity is arranged in a V-shaped cavity structure which is composed of an input mirror, an output mirror and a reflective blazed grating, a diamond crystal is arranged between the input mirror and the output mirror, and the reflective blazed grating is arranged below the diamond crystal. The stability of the laser resonant cavity is improved through the design of the cavity mirror, the wavelength adjustment is accurate to 0.01 nm, and the loss in the transmission process is reduced through the cavity locking frequency doubler of the ring-shaped cavity structure.

The invention discloses a three-stage step type nanoindentation creep test indenter and a preparation method thereof. A working part of the pressure head body is composed of three platform-shaped steps which are sequentially distributed in the direction of a central axis, the cross sectional areas of the three platform-shaped steps are increased in a stepped mode, the overall outline of the pressure head body is in a triangular pyramid shape, the surface of the pressure head body is an sp3 hybrid diamond crystal surface subjected to low-temperature catalytic molten salt etching treatment and without an amorphous carbon damage layer, and the curvature radius of the tip of the first step is smaller than 10 nm; the preparation method comprises the following steps: processing a blank by using a focused ion beam; performing pre-passivation to form a tungsten-containing solid precursor film; immersing into low-temperature molten salt containing a vanadium catalyst for reaction; and finally quenching and cleaning. According to the method, through a catalytic cooling and adsorption shielding cooperation mechanism, the sharp point sharpness is effectively kept while an amorphous carbon damaged layer is removed, parasitic creep interference caused by an amorphous layer is eliminated, and cross-scale graded high-precision testing is achieved.

The present invention provides a method for reducing mutual interference in the growth of diamond crystals based on edge coating treatment, which belongs to the field of diamond growth. The following steps are included: S1: Select suitable diamond seeds and clean the diamond seeds; S2: Perform coating treatment on the four sides of the diamond; S3: Place the seeds into the MPCVD chamber to grow diamond blanks; S4: Treat the blanks after the growth is completed to remove the polycrystalline and graphite at the edges to form diamond single crystals. The beneficial effect of the present invention is that, compared with the prior art: the present invention performs coating treatment on the seeds, so that the edges of the diamond seeds are no longer diamonds, do not have diamond lattices and atoms, and when diamond atoms fall onto the upper surface of the film, only polycrystalline diamond or graphite will be formed, which prevents the seeds from growing horizontally along the edges, thereby preventing the seeds from expanding horizontally and reducing mutual interference in the growth of diamond crystals.

The application discloses an ultrathin diamond clamping device, which comprises, from top to bottom, a graphite pressing block, a polycrystalline diamond limiting sheet, a polycrystalline diamond bottom sheet, a graphite bottom plate and graphite screws for fixing the above-mentioned elements; the polycrystalline diamond limiting sheet is provided with at least one rectangular notch, and the limiting groove for positioning the ultrathin diamond crystal sheet is formed by the rectangular notch and the polycrystalline diamond bottom sheet; the graphite pressing block covers the ultrathin diamond crystal sheet, the graphite screws pass through the graphite pressing block, the polycrystalline diamond limiting sheet and the polycrystalline diamond bottom sheet in sequence and are connected with the graphite bottom plate, the graphite pressing block is extruded by twisting the graphite screws, pressure is applied to the ultrathin diamond crystal sheet to realize clamping. According to the application, the ultrathin diamond clamping device has the advantages of low thermal load, small clamping stress, small radiation damage and the like, reliably supports the stable and efficient generation of the seed laser by the monochromator, and finally helps to realize the high-stability operation of the fully-coherent free electron laser.