75 results about "Crystal rotation" patented technology

A bulk, quasi-periodic phase-matched difference-frequency (DFG) process in field-poled LiNbO.sub.3 bulk crystal permits continuous tunability of the output radiation in the 3.0-4.1 .mu.m wavelength range through grating rotation. DFG in QPM-LiNbO.sub.3 crystal, carried out using a Nd:YAG laser and a high power semiconductor laser at the quasi-phased matching (QPM) degeneracy point, results in an ultra wide 0.5 .mu.m acceptance bandwidth, permitting crystal rotation-free wavelength tuning of 4.0-4.5 .mu.m, with 0.2 mW output power at 4.5 .mu.m.

A closed monocrystalline growth furnace for the molten salt method crystal growth comprises a ceramic bushing hearth wound with a resistance wire, a closed barrel-shaped hollow double-layer stainless steel outer furnace shell positioned outside the hearth, fireproof heat-insulation bricks/cotton arranged between the furnace shell and the hearth, a thermocouple traversing the furnace shell and extending to the outer wall of the hearth, and a fireproof heat-insulation brick furnace cover covering the upper port of the hearth, wherein the center and two sides of the furnace cover are provided with a first vertical central through hole and observation holes respectively; cooling water which flows in a circulating manner is contained in the furnace shell; the wall of the furnace shell is provided with an aspirating hole and an air inlet; the center of the cover of the furnace shell is provided with a second vertical central through hole opposite to the first vertical central through hole, and quartz glass windows; an atmospheric gas is filled to the inside of the furnace shell; a magnetofluid is arranged over the furnace shell and is connected with the furnace shell through a bellow; and a seed crystal rod traverses the magnetofluid, is connected with a universal knot, and is fixed on a crystal rotation head through the universal knot. The furnace enables crystals to grow under the atmospheric gas, the entry of impurities into the crystals to be reduced, the optical properties of the crystals to be improved, the extrinsic absorption generated by the crystals in an ultraviolet spectrum region to be removed, and the ultraviolet laser output power to be improved.

The invention discloses a production method of solar-grade czochralski silicon, and relates to the technical field of czochralski silicon. The production method comprises the following eight steps of charging, melting, stabilizing the temperature, seeding, shouldering, performing equal-diameter growth and ending. According to the production method disclosed by the invention, in the seeding process, the crystal rotation and the crucible rotation are set to be 8 revolutions per minute. The production method is simple and convenient to operate, easy to realize, capable of effectively reducing crystal defects which possibly appear in a crystallization process, lowering a problem of producing black chips and black angle plates in the czochralski silicon, remarkably improving the quality of the single crystal and prolonging the service life of the single crystal, avoiding returned goods due to product quality defects and saving unnecessary fund waste for the enterprises.

The invention discloses a method for preparing and using laser crystal mixed with the ytterbium doped gadolinium lanthanum calcium oxyborate, which relate to the field of the intraocular lens. At a temperature of about 1470 DEG C, the invention, at a crystal rotation speed of 5 to 20 rotations per minute and a pulling rate of 0.5 to 2mm per hour, produce the crystal of Yb<3+>:Gd<1-X>La<X>Ca<4>O(BO3)3 of high quality and larger dimension though a czochralski method. The crystal is a novel laser crystal, which can generate a laser output with a wavelength of about 1 Mum. The crystal also has the frequency-doubled effect and can get blue-green laser output through a self-frequency-doubling or self-mixing nonlinear optical method. A solid laser made from the crystal can be applied in the fields such as spectroscopy, biomedicine, military science and etc.

The invention discloses a processing technology for preparing single crystal silicon by the Czochralski method, which comprises the following steps: necking growth: when the temperature of the silicon melt is stabilized to a certain temperature, the seed crystal is immersed in the silicon melt, and the seed crystal is Increase the pulling speed at a certain rate to reduce the diameter of the seed crystal to 3-7mm; shoulder growth: after the necking growth is completed, reduce the crucible temperature and pulling speed, adjust the crucible rotation speed and crystal rotation speed, and increase the crystal to the required diameter; equal-diameter growth: after the shoulder growth is completed, adjust the crucible temperature, pulling speed, crucible rotation speed and crystal rotation speed, so that the diameter of the ingot is maintained between plus and minus 2mm; the present invention adds pure boron to the single crystal silicon raw material, The mass ratio of pure boron to monocrystalline silicon raw materials is 5%-15%, so that the resistivity of monocrystalline silicon can reach 300Ω/CM, and the radial uniformity of resistivity is within 3%; reduce the oxygen content in silicon melt It effectively inhibits the entry of oxygen from the silicon melt into the silicon crystal, improves work efficiency, and reduces the oxygen content of the silicon crystal.

The invention relates to a method for adjusting the growth temperature of a silicon carbide monocrystal. The method comprises the following steps: enabling a seed crystal and a crucible to be coaxial and to rotate in opposite directions; controlling the temperature field and temperature distribution of a melt by controlling the crystal rotation speed and the crucible rotation speed; enabling an induction coil to be fixed; adjusting the silicon carbide subliming plane to be in the highest point of an induction coil magnetic field all the time by lifting the crucible. The method is stable in temperature change and high in product quality.

The single crystal extraction method is used for shortening the extraction time from the forming of a straight body part to crystal excision from a meltwater, extracting single crystal and improving a rate of finished products. The method comprises a first process, a second process and a third process. The first process forms the straight body part (C2), and the second process is behind the first process. In the final process of forming the straight body part, a lower protruded shape (C3) protruded downwards is formed at the lower end of the crystal, and the third process is configured to cut the lower protruded shape formed in the second process from the silicon meltwater. In the second process, the field density of the horizontal magnetic field is controlled lower than the first process in the range of 800 to 1000 gausses, the crystal extract speed is controlled lower than the first process in the range of 0.2 to 0.5 mm/min, the crystal rotation speed is controlled lower than the first process in the range of 1 to 3 rpm, and the crucible rotation speed is controlled in the range of 0.5 to 5 rpm.

The invention discloses a laser crystal of ytterbrium doped calcium oxygen borate yttrium lanthanum, a preparation method and an application thereof. The invention relates to the field of an artificial crystal, in particular to a laser crystal of ytterbrium doped calcium oxygen borate yttrium lanthanum (Yb3+:Y<1-X>LaXCa4O(BO3)3), the preparation method and the application thereof. At a temperature of about 1500 DEG C, the invention, at a crystal rotation speed of 5 to 20 rotations per minute and a pulling rate of 0.5 to 2mm per hour, produce the crystal of Yb3+:Y<1-X>LaXCa4O(BO3)3 of high quality and larger dimension though a czochralski method. The crystal is a novel laser crystal, which can generate a laser output with a wavelength of about 1 micrometer. The crystal also has the frequency-doubled effect and can get blue-green laser output through a self-frequency-doubling or self-mixing nonlinear optical method. A solid laser made from the crystal can be applied in the fields such as spectroscopy, biomedicine, military science and etc.

The invention relates to a crystal rocking curve measurement method based on an energy resolution detector, comprising the steps of 1, selecting an X-ray tube anode target material and voltage/current parameters based on an X-ray energy range {E} for measurement; 2, determining a Bragg diffraction angle range {theta B}, a crystal rotation angle range {theta T} and a rotation stepping angle; 3, measuring a crystal diffraction energy spectrum of each rotation angle within the {theta T}; 4, correcting the effect of scattering factors in the crystal diffraction energy spectrums; 5, extracting the diffraction strength of X-ray of energy Ej in {E} within a unit interval when theta Ti = theta Bi, so as to obtain a strength variation curve of Ej; 6, performing diffraction peak fitting on the strength variation curve; 7, figuring out a first-order derivative of a fitted diffraction peak, selecting absolute values of a part of the diffraction peak where the slope of the first-order derivative is not less than 0, i.e., the left and right branches of a rocking curve, and splicing to obtain the rocking curve of Ej; 8, repeating steps 5-7 until {E} is traversed, thereby obtaining the rocking curve of the X ray of all energies in {E} to a certain lattice plane of a crystal.

A single crystal production method based on the Czochralski method comprises controlling a number of crucible rotations and crystal rotations so that a number of vibrations for driving a melt, determined on the basis of the number of crucible and crystal rotations during a single crystal growing procedure, is outside a range from 95% to 105% of a number of sloshing resonance vibrations of the melt. In another embodiment, the method comprises controlling a number of rotations of a crystal and crucible, so that when a number of vibrations for driving a melt, determined by the number of crucible and crystal rotations during a single crystal growing procedure, is within a range from 95% to 105% of a number of sloshing resonance vibrations of the melt, the number of vibrations of the melt due to sloshing does not exceed 2000 times during a period when the number of vibrations is within that range.

The present invention relates to artificial crystal, and is especially one kind of self-frequency doubling laser crystal material Yb3+:Gd1-xYxCa4O(BO3)3 and its preparation process. The crystal belongs to the moniclinic system, has space group Cm; has the crystal cell parameter of a=8.080 angstrom, b=16.014 angstrom, c=3.539 angstrom, beta=101.18 deg, and V=449.0 cubic angstrom; and refractive index of 1.69. The monocrystal is grown in Czochralski process at the grown temperature of 1481-1550 deg.c, pulling rate of 0.5-3 mm/hr, crystal rotation speed of 15-40 rpm. The monocrystal has high quality and large size.

The invention relates to a computer imaging technique, especially an X-ray CT data collecting method and rebuilding method, wherein the invention uses diffraction strengthen waist imaging method to use two methods that sample rotation axle is vertical to crystal rotation axle and sample rotation axle is parallel to the crystal rotation axle, to combine and convert collected four groups of CT data, to make rebuild function meet rotation constant property, and use traditional CT method to rebuild the three-dimension distribution of three refractive indexes. And said method comprises that: S1, finding the conditions of X-ray diffraction strengthen waist image; S2, collecting four groups of CT data; S3, combining and converting CT groups, to meet rotation constant property; S43, using traditional CT method to rebuild the three-dimension distribution of refractive indexes in sample.

The invention provides a continuous pulling monocrystalline silicon growth method, and belongs to the field of semiconductor material preparation, wherein the method comprises the steps of material melting, stabilization, neck guiding, shoulder releasing, shoulder rotating, equal diameter and tail ending, wherein the material melting power is gradually increased and heated in the early stage, thematerial melting power in the medium stage is kept at the stable power, and the material melting power is reduced in the later stage; the rotating directions of crystal rotation and pan rotation are opposite in the stabilization process, the temperature of a thermal field is adjusted to the neck guiding temperature, and a feeding device is kept in a feeding state; the crystal growth speed is reduced in the shoulder releasing process, the feeding device is in the feeding state, and the feeding amount is gradually increased; the shoulder rotating process is increased on the basis of the shoulderreleasing; the given temperature in the early stage of the equal diameter process, and the temperature is controlled, and the temperature is reduced in the early stage. According to the continuous pulling monocrystalline silicon growth method, the feeding amount in the crystal growth crucible can be reduced, the continuous feeding of the monocrystalline furnace is achieved, the secondary feedingtime is reduced, the synchronous feeding and crystal growth are achieved, the initial crystal growth crystal source in the crucible is less, and the resistivity distribution is more uniform.

The invention relates to a single crystal growth method of monopotassium phosphate with large caliber and high quality, comprising the following steps: when seed crystal forms a cone, initial growth temperature lowers to the temperature of 0.5 DEG C below solution saturating point, and cone forming begins; cooling rate is controlled at 0.05 DEG/ day; the mode of cooling by stage is adopted after the seed crystal is in phragmocone; the crystal is in phragmocone until 50 DEG C; cooling rate is kept to 0.05 DEG C/ day; at the temperature of 50-35 DEG C, cooling rate is kept to 0.1 DEG C/ day; at the temperature of 35 DEG C to room temperature, cooling rate is kept to 0.15 DEG C/ day; a crystal rotation mode adopts the following circulation sequence: quickening, positive rotating, slowing down, stalling, quickening, reverse rotating, slowing down and stalling; seed crystal rotates at time interval as follows: 20 seconds, 60 seconds, 20 seconds, 20 seconds, 20 seconds, 60 seconds, 20 seconds and 20 seconds; and the positive rotating rate and the reversal rate are kept to 40-60 turns/ minute.

The invention provides a vertical laser interferometry device and method for measuring a flat crystal absolute surface shape, and adopts a method of three-plane mutual inspection to measure the absolute surface shape of three flat crystal working faces. The device comprises the following parts of a device main body containing a laser emitter, a filter, a beam splitter, a collimating lens, an imaging objective lens, an image detector and a processing portion; a reference flat crystal carrying device located directly under the collimating lens and disposed with the same optical axis of the collimating lens for carrying the flat crystal as a reference flat crystal; and a flat crystal rotation carrying device located directly under the reference flat crystal carrying device and disposed with the same optical axis of the reference flat crystal carrying device for carrying the flat crystal as the flat crystal to be tested, wherein the flat crystal rotation carrying device has a fixed disk, arotation carrying portion and a defining portion, and the defining portion is used for limiting the rotating disk to the first position when the rotating disk is switched to a first position and limiting the rotating disk to the second position when the rotating disk is switched to a second position.

The invention relates to a Ce3xGy3(1-x-y)Y3yAl5O12 doped garnet high-temperature scintillation crystal and a preparation method thereof. The chemical formula of the crystal is Ce3xGy3(1-x-y)Y3yAl5O12, the processing steps are as below: the Ce3xGy3(1-x-y)Y3yAl5O12 crystal is grown with a medium-frequency induction heating pulling method, a heating unit is an iridium crucible, the raw materials are weighed according to proportion after calcination, the raw materials are pressed into blocks by a static pressure machine after weighing, matching and uniform grinding and mixing, sintering is performed at the temperature of 1,300 DEG C and solid-phase reaction happens, and the sintered raw materials are preserved in a drying cabinet; zirconium oxide and aluminum oxide are used as an insulation cover and an insulation material respectively, an observation hole is sealed by a gem piece, the inside of a hearth is protected by inert gas, the crystal growth temperature is about 1,950 DEG C, the pulling rate is 0.5-5 mm/h, and the crystal rotation speed is 10-30 rpm. The crystal has the advantages that the crystal growth cost is low, large size is easy to prepare, high-concentration doping is realized, the scintillation property is excellent and the like.

The invention relates to a crystal growth interface electrical signal acquisition system which comprises a crucible, a seed rod, a crystal rotation mechanism and an electrical signal acquisition unit;the crystal rotation mechanism is isolated with an outside furnace body and comprises a crystal rotation rod, a coulpler, a double-shaft motor and an electrical slip ring; the crystal rotation rod iselectrically connected with the seed rod and in a hollow structure, and a conductive core is arranged in the crystal rotation rod; the lower end of the coupler is connected with the conductive core;the double-shaft motor comprises a motor bracket, a motor main shaft and a motor auxiliary shaft, and the motor main shaft is connected with the upper end of the coupler; the fixed end of the electrical slip ring is fixed on the motor bracket, and the free end of the electrical slip ring is electrically connected with the motor auxiliary shaft; the two ends of the electrical signal acquisition unit are electrically connected with the crucible and the fixed end of the electrical slip ring respectively. According to the crystal growth interface electrical signal acquisition system, high-speed acquisition and stable transmission of interface electrical signals can be realized.

This invention provides a crystal rotation lift and pulls equipment that has damping. It is consisted of flanged shaft, flexibie disc, conical surface rotary table, friction cone, seed rod, supporting enclosure and motor. Two flexible discs are fixed between the lower end of the flanged shaft and the upper end of the conical surface rotary table separately, the keep a certain pressure. The friction cone is fixed at the place of conical surface of conical surface roa\tary table, the lower end of the friction cone is connecdted with seed rod, the conical surface rotary table is fixed on the supporting enclosure by bearing, and it can rotate freely. The supporting enclosure is fixed on the motor. This invention transforms the fixed coupling direct drive between the motor and the seed rod into friction drive. It can bring relative slip, so it can eliminate the torque caused by inertia of the motor, and then it will work as active protecion equipment.

A laser crystal mixed with the ytterbium doped lanthanum potassium molybdate and the preparation method as well as the use thereof relate to the field of the intraocular lens.At a temperature of about 1070 DEG C, the invention, at a crystal rotation speed of 5 to 20 rotations per minute and a pulling rate of 0.5 to 2mm per hour, grows the crystal of Yb<3>:KLa(MoO4)2 of high quality and larger dimension through the czochralski method. The crystal is a novel laser crystal, which can generate a laser output with a wavelength of about 1 Mum. A solid laser made from the crystal can be applied in the fields such as spectroscopy, biomedicine, military science and etc.