126 results about "Ktp laser" patented technology

The invention provides a laser plasma sound barrier and magneto-rheological antiknock array collaborative protection method. The method comprises the following steps: firstly, constructing a collaborative protection structure consisting of a laser plasma sound barrier layer and a magneto-rheological antiknock array layer; a shock wave leading signal is detected in real time and input into a preset multi-dimensional feature model, the model dynamically generates a protection strategy, and a sound barrier instruction and an anti-explosion instruction are output respectively. The laser plasma sound barrier layer outputs specific reverse sound waves according to a sound barrier instruction and attenuates shock waves through destructive interference; meanwhile, the magneto-rheological anti-explosion array layer instantaneously solidifies a magnetic field according to an anti-explosion instruction, and shock wave energy is efficiently absorbed. According to the laser plasma sound barrier and magneto-rheological anti-explosion array cooperative protection method provided by the invention, the cooperative protection structure and the preset multi-dimensional feature model are constructed, so that the cooperative effect of the sound barrier and the anti-explosion array is realized, the response speed to shock waves is increased, the energy processing efficiency is improved, and the adaptability and reliability of protection are enhanced.

The invention relates to the technical field of capacitor films. The invention discloses a preparation process of a high-performance polypropylene capacitor film. The preparation process comprises the following steps: A1, preparing a polypropylene capacitor film; a2, carrying out surface cleaning and activation pretreatment on the polypropylene capacitance film; a3, evaporating a gradient modified layer on the surface of the pretreated polypropylene capacitance film; a4, carrying out laser plasma synergistic treatment and crystallinity regulation and control on the modified polypropylene capacitor film; and A5, coating the outer layer of the modified polypropylene capacitance film with a functional layer, and carrying out annealing post-treatment to prepare the high-performance polypropylene capacitance film. The mechanical strength and the electrical stability are improved through nano filler dispersion, two-way stretching and crystallinity regulation and control; through the collaborative design of surface cleaning and activation and a gradient functional layer, excellent interface bonding force and environmental adaptability are given; and by means of technologies such as multi-source evaporation and laser plasma co-processing, precise regulation and control and diversified expansion of the performance are achieved, the method is suitable for various scenes, and the process repeatability is good.

The invention discloses a multi-physics coupling modeling method based on nanosecond laser etching microgroove resistance reduction simulation, relates to the technical field of laser processing, and is used for solving the problem of optimization of a microgroove resistance reduction effect in a laser etching process. According to the method, the drag reduction effect of the microgroove in the laser etching process is simulated by establishing a coupling model of a plurality of physical fields such as heat transfer, fluid dynamics and material removal. Specifically, an adaptive grid technology is adopted to accurately calculate a temperature field and a flow field in an etching process, and meanwhile, a pulse laser equivalent processing method is introduced to model influences of different scanning times and laser power, so that etching process parameters are optimized. According to the method, the drag reduction effect under different parameters can be efficiently predicted, a theoretical basis is provided for microgroove design and laser etching process optimization, and the method has a wide application prospect.

The invention discloses a preparation method of a solar cell, the solar cell and a photovoltaic module, and the preparation method comprises the following steps: providing a silicon wafer, the surface of which comprises a first region and a second region; sequentially forming a doping structure, a dielectric layer and a mask on the surface of the silicon wafer; carrying out patterning opening on the mask by adopting a laser process, and removing the mask in a first region; removing all the dielectric layer in the first region by adopting a wet etching process, and forming a window penetrating to the doping structure along the thickness direction of the silicon wafer in the dielectric layer; removing the mask in a second area on the surface of the dielectric layer; and preparing an electrode in contact with the doping structure at the window of the dielectric layer. According to the method, suede damage and passivation loss caused by windowing of the dielectric layer through laser and other processes can be remarkably reduced, a metallized structure with excellent electrical performance is obtained, the filling factor and the open-circuit voltage are remarkably improved, and the battery efficiency and the assembly power are greatly improved.

The invention relates to the technical field of optical fiber connectors, and discloses an easy-to-assemble optical fiber connector, which comprises an optical fiber connector, and is characterized in that the optical fiber connector cannot be limited in an adapter, and an elastic telescopic column recovers to the original length under the action of an internal micro spring, so that a third annular plate is driven to be separated from the interior of a second annular plate; when the optical fiber connector is separated from the adapter, the optical fiber connector contacts the joint of the optical fiber connector and the adapter, and the optical fiber connector is gradually separated from the adapter under the action of an elastic telescopic column and a third annular plate until the optical fiber connector and the adapter are in a separated state, so that the phenomenon that the optical fiber connector is separated from the adapter due to the influence of external factors such as high-power laser between the optical fiber connector and the adapter is avoided. And the temperature between the two parts is gradually increased, so that the internal components of the two parts are damaged, and even the open fire phenomenon between the two parts can be avoided.

The present invention discloses a laser plasma three-wavelength interference diagnostic device and an adjustment method thereof. The device includes a detection light source system, a plasma excitation system, a detection optical path system and a receiving system. The laser plasma generated by the laser excitation device is placed in the detection optical path of the Mach-Zehnder interferometer. The white pulse light source generated by the detection light source device is used as the detection light. The Mach-Zehnder interferometer divides the detection light into two beams, one beam passes through the laser plasma area, and the other beam is used as a reference light. The two beams meet after passing through the Mach-Zehnder interferometer. The receiving system includes an RGB filter grating and a color CCD. The light after meeting is divided into three beams of light with different wavelengths through the RGB filter grating to form three interference fringe patterns. The device can simultaneously obtain three interference fringe patterns carrying laser plasma phase information, obtain more data graphs, and make the results more accurate, effective and comprehensive.

An easy-to-adjust X-ray source enhancement system based on a cascaded high-density structure comprises a linear gas nozzle, a metal target, a fixed sleeve, a fixed rod and a three-dimensional mobile platform, and can effectively generate a two-stage high-density structure to enhance radiation of a betatron X-ray source. The device has the advantages of simplicity in operation, compact structure, generation of two-stage high-density structure distribution and good stability. The invention relates to the field of interaction of ultra-short and ultra-strong laser plasmas, in particular to a process of accelerating and driving high-brightness X-rays by laser tail field electrons, in the first stage, generated density falling edges are used for generating electron injection, and stable generation of large-charge electrons is promoted. And the second stage utilizes the characteristics of the high-density platform region to enhance the lateral oscillation of electrons, thereby improving the X-ray radiation energy and photon yield.

The invention provides a gas target generation method and device and an accelerator, and relates to the technical field of laser plasma accelerators. The gas target generation method provided by the invention comprises the following steps: placing a blocking sheet at a gas outlet; the gas target material is accelerated and sprayed out through a gas outlet so as to generate oblique shock waves, and then a gas target is formed; the laser pulse and the gas target act to form a tail wave field formed by plasma, ionization injection is carried out, and the complex phase and density gradient injection process is accelerated. Accelerating electrons are captured in the ionization injection process in the gas target density uniform distribution section, and electron beams reaching the deceleration phase return to the acceleration phase again through the acceleration multiphase process in the density rising section of the gas target, so that the acceleration distance is prolonged; through the density gradient injection process in the gas target density descending section, the charge quantity of electron beams is increased, the transverse amplitude is increased, and the number of single luminous photons of the Betatron X-rays is further efficiently increased.

The invention discloses an electromagnetic shielding case formed based on ultrafast laser plasma, and the electromagnetic shielding case comprises an ultrafast laser which is used for emitting ultrafast laser; the phase modulation element is used for carrying out annular modulation on the phase of the ultrafast laser to enable the cross section of a light beam to be in an annular shape; and the focusing device is used for pre-focusing the annular modulation light emitted by the phase modulation element in air to form a hollow cylindrical plasma cylinder, and the plasma cylinder is used for being nested at the periphery of equipment to be shielded so as to realize a signal shielding effect. Therefore, the generation and dissipation process of the ultrafast laser plasma is very rapid and can be completed on the nanosecond-level time scale, rapid response to electromagnetic waves can be achieved, and the method is suitable for occasions where the shielding effect needs to be dynamically adjusted.

The invention provides a method for measuring and compensating drifting and jittering of the position of an X-ray source, and relates to the technical field of X-rays. The method for measuring and compensating the drift and jitter of the X light source position comprises the steps that the original point of the initial position of the X light source driven by a laser plasma accelerator is collected; collecting the real-time jitter offset of the X light source in the application time; counting a real-time jitter offset, and calculating to obtain an average jitter offset within a specified time; the position of the laser target spot is adjusted according to the average jitter offset, so that the offset of the X light source is fed back and pre-compensated; and correcting a corresponding result generated by the X light source through data post-processing. According to the invention, through the synergistic effect of the method for adjusting the position of the laser target spot and the method for post-processing the data, the high-frequency jitter of the average jitter offset and the real-time jitter offset generated in the application process is compensated and corrected, and the precision and accuracy of the obtained result are improved.

The invention relates to the technical field of photoetching machine chip manufacturing. The invention relates to a method for changing wavelength of light waves by adding a deuterium medium to a photoetching machine. The method is characterized by mainly comprising a glass container (1) and deuterium (2). Light sources such as laser pass through the deuterium (2) in the glass container (1), the deuterium (2) and the light sources such as laser generate resonance, and the resonance generates light with shorter wavelength.

The present invention relates to a laser precision adjustment device, comprising: a first power source, an output end of which is used to provide a driving force for moving along a first direction; a linkage module, which is connected to the output end of the first power source and has multiple connecting parts, and the multiple connecting parts are driven by the first power source to move at equal intervals along the first direction; multiple support plates, with one support plate correspondingly connected to one connecting part; multiple mirror modules, with one mirror module installed on a support plate and comprising a reflector group and a galvanometer, the reflector group being used to receive and reflect laser light emitted by the laser module, and the galvanometer being used to receive reflected light from the reflector group and perform precision compensation; the multiple connecting parts are equidistantly moved in the first direction to realize equidistant adjustment of multiple lasers, and the laser light is highly precisely compensated in the galvanometer after being reflected by the reflector group, so that the product yield is high, the production capacity is high, the structure is relatively simple, it is easy to operate, the maintenance cost is low, the debugging is convenient, and the long-term operation stability is high.

The invention discloses a laser plasma additive composite welding device which comprises a workbench, a moving mechanism, a composite welding assembly and a rolling device, the moving mechanism comprises a transverse moving device, a longitudinal moving device, a vertical moving device and a portal frame, and a mounting part is arranged on a movable part of the vertical moving device; the composite welding assembly and the rolling device are arranged on the installation part at intervals, the composite welding assembly comprises a laser welding head and a plasma welding head, the rolling device comprises a support, a roller part and an elastic part, the upper portion of the support is connected with the installation part, the lower portion of the support is movably connected with a movable strip, and the movable strip is provided with a rotating shaft for being rotationally connected with the roller part. The elastic piece acts between the support and the movable strip, and the roller piece is sleeved with a heat-resisting ceramic sleeve. According to the plate-shaped part repairing device, the pressing roller device is driven by the moving mechanism to move, and the repairing material is pressed into the molten pool in a rolling mode, so that the damaged area of the plate-shaped part is fully filled with the repairing material, and the quality of the repaired plate-shaped part is guaranteed.

This article is a polishing pad comprising a polishing layer and a cushioning layer laminated together. The partial design features a configuration in which a plate-shaped window made of a transparent material is fitted into a recess formed in the polishing layer, and the product is used by transmitting light such as laser light through the window.

The present application relates to a kind of adjustable thrust and specific impulse of multi-working substance mixed effect laser plasma micro-propeller, solid working substance supply system includes multiple solid working substance, wherein one solid working substance is located in the middle, the rest is uniformly arranged in the periphery of the solid working substance in the middle along the circumferential direction, each solid working substance is fixed on the installation base by fixed assembly B, the material of each solid working substance is two or more than two in metal, high molecular polymer, energy material;Laser system includes control power supply and multiple laser assembly, the number of laser assembly is same with the number of solid working substance, one-to-one correspondence, wherein one laser assembly is located in the middle, the rest is uniformly arranged in the periphery of the laser assembly in the middle along the circumferential direction.The present application can make the thrust and specific impulse generated by propeller can be adjusted in a large range by adjusting the independent action of laser and single solid working substance or the coupling effect of laser and multiple types of solid working substance, satisfy more complex space task.

This application provides a method, apparatus, and accelerator for generating a gas target, relating to the field of laser plasma accelerator technology. The method for generating a gas target includes placing a baffle plate at a gas outlet; accelerating a gas target material and ejecting it through the gas outlet to generate an oblique shock wave, thereby forming a gas target; and using a laser pulse to interact with the gas target to form a wake field composed of plasma, resulting in ionization injection, accelerated phase re-phase, and density gradient injection processes. This application captures accelerated electrons during the ionization injection process in the uniform density distribution section of the gas target, extends the acceleration distance by allowing the electron beam, which has reached a deceleration phase, to return to the acceleration phase during the accelerated phase re-phase process in the density rising section of the gas target, and increases the charge and transverse amplitude of the electron beam during the density gradient injection process in the density falling section of the gas target, thereby efficiently increasing the single-emittance number of Betatron X-rays.

The application relates to a kind of plasma diagnostic method and device based on femtosecond laser filament probe, belong to laser plasma diagnostic technical field, method utilizes the high peak power characteristics of femtosecond laser to form the femtosecond filament probe with only hundred microns in diameter and only several millimeters in length, and the internal substance of plasma can be excited again.Spectra signals when using and not using femtosecond filament probe are collected respectively, and the element information at the position of femtosecond filament probe at this moment is obtained by differentiating the spectrum.By scanning the relative position of femtosecond filament probe and plasma, the material content information at different spatial positions in plasma can be obtained, and by changing the delay time when femtosecond laser pulse and plasma are generated, the material distribution information in plasma at different time can be obtained, and the four-dimensional distribution information of the material in plasma can be obtained by coincidence of the spectrum under different positions and different delay times.

The invention relates to a technology for enhancing the cohesiveness of a carbon-carbon matrix and a SiC ceramic powder coating, and relates to the technical field of high-end brake materials, and the specific bonding steps are as follows: taking a carbon fiber preform plate as a raw material, placing in an isothermal chemical vapor deposition furnace, depositing for 150-200 hours at 1000-1100 DEG C and normal pressure, and increasing the density to 1.3 g / cm < 3 > to obtain a carbon / carbon composite material blank; according to the technology for enhancing the cohesiveness of the carbon-carbon matrix and the SiC ceramic powder coating, coating preparation is completed through three steps of CNC mechanical slotting, phenolic resin-SiC powder hot pressing and primary fusion siliconizing, and laser / plasma surface modification or 1-5 [mu] m isotropic carbon transition layer deposition needed in the prior art is completely replaced; equipment is simplified from a laser / plasma or high-temperature CVD (Chemical Vapor Deposition) system to a conventional CNC (Computer Numerical Control), a hot press and a siliconizing furnace, and the investment of a single production line is reduced by more than 30%; the production period is shortened from 7-10 days to 2-3 days, manpower and energy consumption are synchronously reduced, the unit cost is reduced by 25%-40%, and low-cost and large-scale industrial production is truly achieved.

The invention provides a mold sticking excess material cleaning device and method. The mold sticking excess material cleaning device comprises a heating table, a supporting rod, a mold table and a scraping piece. The bottom end of the supporting rod is connected with the side face of the heating table. The mold table is arranged above the heating table. The mold table is of a frame structure, and the bottom face of the side face of the mold table is connected with the top face of the heating table. And the scraping blade is connected with the upper end of the supporting rod. When the mold sticking excess material cleaning device is used for cleaning mold sticking excess materials, the scalding risk does not exist, safety and effectiveness are achieved, and operation is convenient and fast; the die surface cannot be damaged, and the service life of the die is prolonged; extra conditions such as mold cleaning glue and laser are not needed, the structure is simple, and the cost is low.

The invention provides an image bright field correction method and device for a laser plasma accelerator, electronic equipment and a storage medium, and relates to the technical field of X-ray imaging. The method comprises the following steps: acquiring dark fields and initial X-ray beam spot images of an X-ray bright field calibration detector and an X-ray imaging detector to obtain coordinates of an initial X-ray beam spot center; under the condition that the imaging sample is moved in, a real-time unprocessed X-ray beam spot image obtained by the X-ray bright field calibration detector and a real-time unprocessed projection image obtained by the X-ray imaging detector are obtained, so that a real-time beam spot image and a real-time imaging image are obtained, and coordinates of a real-time X-ray beam spot center are obtained; according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, the X-ray beam spot center is obtained, and a final real-time projection image is obtained. According to the invention, the accuracy of bright field correction is improved by measuring the X-ray beam spot in real time and combining geometric space mapping and coordinate transformation.

The utility model discloses a laser obstacle removing device, which relates to the technical field of laser equipment, and comprises an optical ranging aiming lens, a laser emission lens, an electric holder and a control panel, and the optical ranging aiming lens and the electric holder are respectively arranged at the top and the bottom of the laser emission lens. The optical ranging aiming lens is used for measuring the distance between the laser obstacle removing device and a target, a distance signal is used as a focusing parameter to guide the laser emitting lens to focus, the optical ranging aiming lens transmits a target image back to the control panel, and the laser emitting lens is used for bearing input and output of high-energy laser. The focus of a laser beam is adjusted through a distance signal of an optical ranging aiming lens, the electric holder has the rotating freedom degree in the horizontal direction and the vertical direction, the functions of system rotation, aiming, laser focusing and emitting and the like are achieved through a control panel, and the problems that a laser obstacle removing device is complex in structure, not attractive in appearance, incomplete in function and high in practicability are solved. And the operation is troublesome.

The invention provides a calibration device and method for an ultraviolet wavemeter, and relates to the technical field of atomic filtering, and the calibration device comprises the steps: a tunable continuous laser generates narrow-linewidth continuous laser; the first non-polarization beam splitting prism performs beam splitting on the narrow-linewidth continuous laser to obtain first laser and second laser; the wavelength meter obtains a measurement wavelength value of the first laser; the second non-polarization beam splitting prism performs equal-proportion beam splitting on the second laser to obtain third laser and fourth laser; the first photoelectric detector obtains the first signal intensity of the third laser; the atomic light filter absorbs energy at the central wavelength of the fourth laser by using alkali metal barium steam in a metastable state and outputs fifth laser; the second photoelectric detector obtains the second signal intensity of the fifth laser; and the control system scans a preset wave band, records a plurality of preset wavelength values and ratios between the plurality of corresponding second signal intensities and the plurality of first signal intensities to obtain a transmittance curve, and calibrates the wavemeter according to the absorption peak position of the transmittance curve.

A laser-plasma synergistic surface treatment method for CFRP / titanium alloy heterojunctions belongs to the field of heteromaterial bonding technology. First, nanosecond pulsed lasers are used to etch the surfaces of CFRP and titanium alloy to be bonded, constructing a micro-nano composite structure. Then, atmospheric pressure cold plasma is used to activate the etched surfaces, grafting polar functional groups. Finally, the two are bonded and cured using an adhesive. This invention achieves a dual enhancement effect of "mechanical interlocking" and "chemical bonding" by organically combining "laser etching to construct micro-nano physical structures" and "plasma activation to introduce chemical functional groups," significantly improving the interfacial bonding strength of CFRP / titanium alloy heterojunctions. Compared with single treatment methods, this invention can increase the joint shear strength by more than 38%, and the failure mode changes from interfacial failure to cohesive failure. It has advantages such as environmentally friendly process, good controllability, and significant effects, and has broad application prospects in aerospace, high-end equipment manufacturing, and other fields.

The invention discloses a device and a method for testing transmission of electromagnetic waves in an ultrafast laser plasma channel. The device comprises a linear antenna, a signal generating device and a signal receiving and analyzing device, the linear antenna adopts a coaxial copper inner core; the two linear antennas are arranged at the two ends of the ultrafast laser plasma channel respectively, one linear antenna serves as a transmitting antenna, and the other linear antenna serves as a receiving antenna; the signal generating device is connected with the transmitting antenna and used for transmitting electromagnetic wave signals. The signal receiving and analyzing device is connected with the receiving antenna; wherein the electromagnetic wave signal is transmitted to the signal receiving and analyzing device through the transmitting antenna, the ultrafast laser plasma channel and the receiving antenna in sequence, and the signal receiving and analyzing device is used for analyzing the transmission characteristics of the electromagnetic wave signal of the to-be-detected wave band in the ultrafast laser plasma channel. Therefore, the process of transmitting the electromagnetic waves by the plasma channel can be conveniently analyzed, and the transmission test efficiency of the electromagnetic waves in the ultrafast laser plasma channel is improved.

Protective eyewear that may provide a full field of view while shielding users from unsafe, harmful, or unwanted visual elements, including high-intensity sources such as lasers, is described. Such shielding may include, for instance, capturing, attenuating, transforming, filtering, and / or otherwise processing such unsafe, harmful, or unwanted visual elements for presentation to users. The protective eyewear may enhance visual elements, such as by increasing brightness or contrast. The protective eyewear may allow users to see visual elements outside their normal or expected range such as ultraviolet and infrared. The protective eyewear may include one or more cameras that may capture visual information associated with the user environment. The captured information may be analyzed and processed such that harmful or unwanted visual elements are removed and / or otherwise processed to be made safe for viewing. After processing, the captured information may be rendered and provided via a display of the protective eyewear.

The utility model discloses a laser-plasma dual-energy-source composite directional energy deposition device which comprises a connecting plate. The laser assembly comprises a laser and a laser deposition head, and the laser emits laser to the laser deposition head; the plasma assembly comprises a plasma welding machine and a plasma stacking and covering head, and the plasma welding machine outputs plasma electric arcs to the plasma stacking and covering head; and the powder feeding assembly comprises a powder feeder and a powder uniformizing device, and the powder feeder is connected with the powder uniformizing device and supplies metal powder to the powder uniformizing device. The internal structure of the part is formed through the plasma stack covering head, and the outline of the part is formed through the laser deposition head, so that higher machining efficiency is achieved when the internal structure of the part is machined, and higher machining precision is achieved when the outline of the part is machined. The utility model relates to the technical field of laser 3D printing.

The invention discloses a controlled aerosol laser-induced breakdown spectroscopy detection method and device, and relates to the technical field of laser plasma emission spectroscopy. The method comprises the following steps: placing a to-be-detected sample with fixed mass in a closed cavity filled with inert gas; ablating all the to-be-detected samples in the closed cavity by using laser with fixed wavelength, mixing ablated to-be-detected sample particles with inert gas to form aerosol with uniform mass density, and exciting the aerosol to form plasma; the plasma spontaneously emits light; one or more of pressure intensity, double-pulse excitation and resonance excitation in the closed cavity are regulated and controlled, so that the intensity of light emitted by the plasma is enhanced; and obtaining the content of the to-be-analyzed element in the to-be-detected sample according to the intensity-enhanced plasma emitted light. According to the method, the influence of the matrix effect on the laser-induced breakdown spectroscopy technology can be reduced, and the quantification accuracy is improved.

This invention provides a frequency-domain shaping laser-plasma resonance sintering system using aerosol jetting. The localized strong electromagnetic field excited by LSPR can induce electron cloud rearrangement and chemical bond reconstruction at the interface of adjacent nanoparticles, forming an atomic-level interdiffusion transition layer. This invention precisely controls the laser wavelength through frequency-domain shaping technology to match the LSPR characteristic peaks of the nanoparticles, maximizing the local electromagnetic field enhancement effect. This allows for the completion of nanoparticle melting and necking formation at ultra-low laser power, overcoming the energy efficiency limitations of traditional post-processing techniques such as high-temperature furnace heating. Simultaneously, this process is completed within the femtosecond to picosecond timescale, avoiding component segregation caused by high-temperature thermal diffusion and significantly improving the bonding strength of the nanoparticle interface. Furthermore, it achieves nanoscale selective heating, completing particle melting and necking formation at ultra-low laser power, avoiding overall thermal damage.

The invention relates to a preparation method and application of a self-repairing conductive pattern of a polydimethylsiloxane substrate, amino silicon oil (PDMS-NH2) is used as a main material, a metal salt is added, the amino silicon oil is cross-linked and cured, and a PDMS material containing metal particles is formed. Wherein the metal salt and the amino silicon oil (PDMS-NH2) form metal coordination, so that the self-repairing function of the PDMS is improved, and the metal particles can be further reduced into metal simple substances by means of laser, plasma and the like, so that active sites are provided for chemical plating reaction, and a conductive image with self-repairing capability is formed on the surface of the PDMS through the chemical plating reaction. The preparation method has the advantages of being simple in preparation process, short in technological process, low in equipment investment, high in cost performance, recyclable and the like, and can be widely applied to preparation of conductive interconnection patterns of intelligent electronic products such as foldable screen electronic devices, flexible sensors and wearable devices.

This article is a polishing pad comprising a polishing layer and a cushioning layer laminated together. The partial design features a configuration in which a plate-shaped window made of a transparent material is fitted into a recess formed in the polishing layer, and the product is used by transmitting light such as laser light through the window.