8 results about "Thin crystal" patented technology

This application discloses a method and device for fabricating a periodically polarized ultrathin lithium niobate / lithium tantalate device, belonging to the field of nonlinear optical device manufacturing. The method includes: fabricating and polarizing periodic electrodes on a provided ferroelectric crystal wafer to form a periodically polarized master wafer; bonding the master wafer to a carrier substrate using optical resin-assisted bonding or direct bonding to form a composite structure; thinning and polishing the side of the master wafer away from the carrier substrate to obtain an ultrathin periodically polarized crystal functional layer; and fabricating the structure of the ultrathin periodically polarized crystal functional layer to obtain a periodically polarized ultrathin lithium niobate / lithium tantalate device. This method avoids the inherent problems of high-voltage breakdown and poor domain quality in existing technologies when directly polarizing ultrathin crystals by placing the high-risk polarization step on a thick, stable wafer.

The application provides a preparation method and a centering device of a size-controllable ultrathin high-quality echo wall optical crystal microcavity, and the method comprises the following steps: cutting a crystal material into a wafer and grinding and thinning the crystal thickness by using a polishing disc; placing an optical crystal microcavity blank on a microscope stage, adjusting two-dimensional adjustment knobs of the stage, and making the center of the optical crystal microcavity blank coincide with an origin of an objective micrometer scale; making a clamping rod with an adhesive adhered to a bottom end penetrate a top end through hole of a clamping rod fixing frame, and making the clamping rod align with the origin of the objective micrometer scale; adjusting the height of the clamping rod, making the optical crystal microcavity blank be pasted and fixed on the bottom end of the clamping rod by ultraviolet curing glue, and completing centering; taking the clamping rod off the clamping rod fixing frame, chamfering an outer circle of the optical crystal microcavity blank; grinding the outer circle surface of the optical crystal microcavity wafer by using sandpaper; polishing the optical crystal microcavity wafer, and obtaining the optical crystal microcavity based on the polished optical crystal microcavity wafer.

This invention discloses a multi-stage cascaded laser frequency doubling device, belonging to the field of laser frequency doubling technology. It includes a front-end frequency doubling module and at least one cascaded frequency doubling module arranged sequentially along the optical path. The cascaded frequency doubling module includes a second-harmonic crystal, a third-harmonic crystal, a beam splitter, a delay adjustment device, and a beam combiner. The front-end frequency doubling module, beam splitter, second-harmonic crystal, beam combiner, and third-harmonic crystal are connected sequentially. By extending the multi-stage continuous cascaded crystal architecture, the long crystal is split into a sequence of thin frequency doubling crystals, suppressing time drift and pulse broadening. Each stage is equipped with a multi-band fully transparent film system to reduce dispersion. Furthermore, a beam splitting and beam combining bypass and dynamic time delay compensation are designed to achieve precise spatiotemporal beam combining of ultraviolet light, enabling femtosecond lasers to possess both high efficiency, low broadening, and excellent pulse quality.

This invention provides a method and system for analyzing the surface shape changes of coatings on ultrathin crystal devices based on finite element analysis, belonging to the field of data processing technology. The method includes: calculating the displacement gradient tensor of subdomain elements to obtain entropy correction coefficients; correcting the amplitude of a uniformly distributed mechanical load based on the entropy correction coefficients to obtain a final uniformly distributed mechanical load; reloading the final uniformly distributed mechanical load into a numerically corrected configuration, repeating the solution and load correction process until the absolute difference of the entropy correction coefficients between two adjacent iterations is less than a preset tolerance, obtaining a final convergent potential field; and extracting the nodal displacement distribution on the substrate surface based on the final convergent potential field to obtain the surface shape change result. This invention can more accurately solve the displacement field and surface shape changes of ultrathin crystal devices after coating, effectively improving the convergence stability and numerical reliability of surface shape analysis.

The application discloses an ultrathin defect-free ZIFs@GO composite film, a preparation method and application thereof, and comprises the following steps: 1) preparing GO by a modified Hummers method; 2) depositing GO on a polymer base film to prepare a GO composite film; and 3) growing ZIFs coordination polymers on the GO composite film by an interfacial counter-diffusion method to prepare the composite film. The application optimizes the ZIFs synthesis conditions and reduces non-selective defects to improve the separation performance of the ZIFs film. In the reverse diffusion process, GO acts as a barrier to make the precursor diffuse along the interlamellar gap and greatly slow down the diffusion rate; by optimizing the driving force of diffusion in the solution, the ZIFs crystallization rate can be accurately matched, the ZIFs growth content can be effectively reduced, and the generation of intercrystalline defects can be reduced. The GO lamella is rich in oxygen functional groups, which provides sites for the heterogeneous nucleation of ZIFs, especially at the edges and defects of the GO lamella, so that the non-selective defects in the GO film can be effectively reduced; meanwhile, the nanoscale limitation enables the ZIFs heteroepitaxial growth to be carried out along the two-dimensional channel instead of the vertical direction, which is beneficial to the formation of an ultrathin crystal structure and realizes the preparation of the ultrathin defect-free composite film.

The utility model relates to the field of fine crystal bar machining auxiliary devices, in particular to a diameter fine crystal bar machining auxiliary tool. Comprising a placing plate, a plurality of rolling wheels are installed on the lower surface of the placing plate, a fixing plate is installed on the upper surface of the placing plate, a moving device is installed on one side of the fixing plate, a handle is fixedly connected to the other side of the fixing plate, an adjusting structure is arranged on the inner wall of the placing plate, and the adjusting structure comprises an auxiliary plate. The auxiliary plate is slidably connected with the placing plate, a plurality of connecting holes are formed in the two sides of the auxiliary plate, the two sides of the placing plate are fixedly connected with two positioning plates, and the inner walls of the two positioning plates are rotatably connected with the same screw rod. According to the auxiliary tool for machining the diameter fine crystal bar, the area of the placing plate can be increased, so that the fine crystal bar is more stable in the placing process, the fine crystal bar is prevented from being suspended, and the safety of the fine crystal bar is further improved.

This invention relates to the field of molecular sieves, specifically to an SCM-36S molecular sieve, its preparation method, applications, compositions, and methanol conversion methods. This molecular sieve exhibits specific X-ray diffraction pattern characteristics. The SCM-36S molecular sieve with the X-ray diffraction pattern characteristics of this invention has thin crystal thickness, large external specific surface area, high acidity, high concentration of strong acids, and rapid molecular diffusion, resulting in high activity and stability. Using the molecular sieve of this invention in alkylbenzene cracking reactions or methanol conversion to olefins and / or aromatics yields high reactant conversion rates, product yields, and long service life.

The application discloses a time-domain spectrum system capable of generating and detecting ultra-wideband terahertz pulses. The system comprises a laser light source, a light splitting module, an optical path adjustment coupling module, a terahertz emission module, a sample detection module and an electro-optic sampling module. After the laser pulses output by the laser light source are split, the pump light is chopped, modulated, expanded and irradiated to a spin terahertz emitter to generate ultra-wideband terahertz pulses of 0.1-10 THz. After the terahertz pulses interact with the sample through a confocal off-axis parabolic mirror, the terahertz pulses are collimated and output again. The detection light formed by light splitting is adjusted in optical path and coincides with the terahertz pulses in time and space, and is focused on an ultra-thin ZnTe crystal in the <110> crystal direction. Finally, the terahertz time-domain signal is obtained through electro-optic sampling. The system has the functions of emitting and detecting ultra-wideband terahertz pulses, and can be used not only in the fields of material detection and physicochemical analysis, but also in the precise verification of the characteristics of other terahertz sources and detection crystals.