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Laser crystal development trend

February 22, 2019 by zengbin  

From the perspective of the entire VUV, UV and IR grade MgF2 optics, device and machine equipment, the developed countries such as the United States and Japan are major industrial countries, and they have a monopoly position in large-scale production of nonlinear optical crystals such as LiNbO3. Small-scale materials such as KTP, BBO, LBO, etc., mainly dominated by China and Lithuania. In terms of device manufacturing, due to the strong technical strength and good industrial base, developed countries such as the United States and Europe occupy a decisive dominant position. Developed countries such as China can only provide low-cost plano/spherical/aspherical/cylindrical MgF2 optics materials to developed countries and earn a small profit. 1) Development of ultraviolet light to shorter wavelength bands The development of all-solid-state deep ultraviolet (200nm) coherent light source is one of the most advanced research projects in the field of optoelectronics in the world. This is because UV lasers have important applications in many high-tech fields, such as the new generation of integrated circuit lithography. All-solid-state UV-coherent light source; in photoelectron spectroscopy and spectroscopy, there is an urgent need for a tunable all-solid-state deep-UV coherent light source, which will play a key role in promoting the development of deep ultraviolet spectroscopy and spectrometers, and will open up A new field of material science research; deep ultraviolet coherent light sources will also greatly promote the development of laser precision machinery processing industry. Since there is no laser crystal directly outputting deep ultraviolet wavelength, the key problem of solving solid-state deep ultraviolet laser light source is concentrated on the development and application development of NLO frequency conversion crystal in the ultraviolet band, which is very attractive to the development of related industrial development and technological progress. Human. 2) Improvement of existing nonlinear optical crystal properties and development of new crystals One of the most typical examples is the stoichiometric ratio of LiNbO3 (abbreviated as SLN). Due to the improved structural integrity, SLN has a superior flying over the performance of the conventional uniform lithium niobate (CLN). If the practical technology is solved, It will revolutionize the field of optoelectronics and optical communication. - BBO is a wholesale large size infrared Silicon optics that is first used to quadruple the 1064 nm laser output from Nd:YAG to obtain 266 nm ultraviolet light. It has been used for decades in this field of frequency conversion. However, when the output of the 266 nm laser exceeds 180 mW, the crystal is damaged by photorefractive damage. Recently developed mature CLBO crystals, not only crystal growth is easier than BBO, the single crystal grows larger than BBO, and it is not broken when the output of 266nm reaches 40 watts. In this area, CLBO has a tendency to replace BBO.

Crystal type and blank

February 21, 2019 by zengbin  

There is a direct relationship between the crystal blank and the quality of the molded product. By the way, most VUV, UV and IR grade MgF2 optics can be molded into molded articles. However, a low-cost plano/spherical/aspherical/cylindrical MgF2 optics having a high softening point has a slight reaction with the mold due to a high molding temperature, so that the life of the mold is short. Therefore, from the viewpoint that the mold material is easy to select and the service life of the mold can be prolonged, a crystal suitable for molding under low temperature (about 600 ° C) should be developed. However, the developed crystals suitable for low temperature molding must conform to the requirements of being able to inexpensively manufacture blanks and materials that do not contain environmental pollution (such as PbO, As2O3). There are requirements for wholesale large size infrared Silicon optics blanks used in compression molding: The surface of the blank before the press must be kept very smooth and clean; 2 in the appropriate geometry; 3 have the required capacity. The blanks are generally selected from spherical, round or spherical shapes and are formed by cold grinding or hot forming.

Laser crystal composition

February 20, 2019 by zengbin  

The laser crystal consists of two parts, a matrix crystal and an activated ion. The various physicochemical properties of laser crystals are mainly determined by the matrix crystal, and its spectral properties are mainly determined by the activated ions. However, the LiSAF, LiSGaF and LiCAF laser crystals and the activating ions interact with each other, so the activation ions have a certain influence on the physicochemical properties of the laser crystal, and the influence of the matrix crystal on its spectral properties is sometimes quite important. As the matrix crystal of the laser crystal, most of the optical crystals are currently used. However, it is not suitable for any kind of optical crystal to be used as a laser crystal. The laser crystal must meet the basic requirements. The following are summarized: In the illuminating mechanism that activates ions, metastable state must be formed to form a three-level or four-energy vertical mechanism; and the metastable state is required to have a long life, so that the number of particles is easy to accumulate and reverse. In order to make the laser crystal have higher efficiency and low oscillation value, the four-level is superior to the three-level in terms of the energy level mechanism. When the energy interval between the final state and the ground state is greater than 1000 cm-1, the final energy level is almost empty at room temperature. Therefore, pumping at room temperature is also prone to particle number inversion. At present, various activated ions of laser light have been generated in the wholesale LiSAF, LiSGaF and LiCAF laser crystals, with Nd3+ ion ****, which is a four-level mechanism, and the distance between the final state of the large size GTR-KTP nonlinear crystal and the ground state energy level is about 1950 cm. Laser crystals must have a variety of spectral properties. Including absorption spectroscopy properties, it is required to have a wide and many absorption bands in the radiant light of the excitation source, a high absorption coefficient, and the absorption band and the peak of the radiation band of the light source overlap as much as possible, which is beneficial to make full use of the excitation light source. Energy; fluorescence spectral properties, generally require that its fluorescence band is small and narrow, so that the output energy is not dispersed; at the same time, in order to convert the absorbed excitation light energy into laser energy as much as possible, the quantum efficiency of fluorescence is required to be as high as possible. The internal energy loss is as small as possible.

What is a laser crystal?

February 19, 2019 by zengbin  

There is a very interesting kind of VUV, UV and IR grade CaF2 optics that produces different charges at both ends when you squeeze or stretch it. This effect is called the piezoelectric effect. A crystal that produces a piezoelectric effect is called a piezoelectric crystal. Crystal (α-quartz) is a well-known piezoelectric crystal. Common piezoelectric crystals are: sphalerite, cubic boron, tourmaline, zincite, GaAs, barium titanate and its derived structural crystals, KH2PO4, NaKC4H4O6·4H2O (rose salt), sugar and so on. Piezoelectric crystals are electronic materials that are second only to single crystal silicon. They are used to manufacture electronic components for selecting and controlling frequencies. They are widely used in various fields of electronic information industry, such as color TV, air conditioner, computer, DVD, and cordless communication. Especially in high-performance electronic devices and digital devices, the application is expanding. The low-etching tunnel density piezoelectric crystal is an essential material for the production of SMD frequency chips and mobile phone frequency chips. The main types of piezoelectric crystal products are: Z rod, Y rod, thickness sheet, frequency sheet. Piezoelectric effect of customized large size and special shape CaF2 optics Some crystals, when subjected to an external force in a certain direction, will have a polarization phenomenon inside, causing the charged particles to be relatively displaced, thereby generating charges of opposite magnitude and opposite signs on the crystal surface; when the external force is removed, it is restored to no Charged state. The amount of charge generated by the force of the crystal is proportional to the amount of external force. This phenomenon is called the piezoelectric effect. Conversely, if an electric field is applied to the crystal, the crystal will mechanically deform in a certain direction; when the applied electric field is removed, the deformation will also disappear. This phenomenon is called the inverse piezoelectric effect and is also called the electrostrictive effect. Principle of piezoelectric effect The cause of piezoelectricity is related to the crystal structure. The positive and negative charges centered on each other are pressed and separated to form an electric dipole, so that the ends of the procurement high efficiency optical window in a specific direction have different amounts of charge. Common features of piezoelectric crystals: crystal point groups (symmetric) have no center of symmetry. Among the 32 point groups of the crystal, 21 point groups do not have a symmetry center, but the crystal of the point group 432 does not exhibit piezoelectricity, so that the crystals of 20 point groups have piezoelectricity.

Application of optical components

February 15, 2019 by zengbin  

Quantum well semiconductor high-powercustom infrared spherical/aspherical/cylindrical Silicon lenses have important applications in laser processing of precision mechanical parts, and also become the most ideal and high-efficiency pumping source for solid optical components. Due to its high efficiency, high reliability and miniaturization This has led to the continuous updating of solid optical components. Let's take a look at some common optical components: In the printing and medical fields, high-power VUV grade LiF optics components are also used. In addition, such as long-wavelength optical components (in 1976, people used Ga[nAsP/InP to realize long-wavelength optical components) for optical communication, short-wavelength optical components were used. Optical disc readout. Since NaKamuxa realized GaInN/GaN blue optical components, visible optical components have been widely used in optical disc systems, such as CD players, DVD systems and high-density optical memory visible-surface emitting optical components in optical discs, printers, displays. There are important applications in this, especially for red, green and blue-emitting optics. Blue-green optical components for underwater communication, laser printing, high-density information reading and writing, deep water detection and applications For large screen color displays and high definition color TV sets. In summary, visible light optical components are widely used in color display light sources, optical storage read and write, laser printing, laser printing, high density multispectral/cleartran and standard CVD ZnS optics storage systems, bar code readers, and pump sources for solid optical components. Uses. New optical components for quantum cascade lasers are used in environmental detection and medical inspection. In addition, since optical components can achieve wavelength tuning by changing magnetic fields or adjusting current, and laser output with narrow line width can be obtained, the use is utilized. Optical components can be studied in high-resolution spectroscopy. Tunable optical components are an important tool for the rapid development of laser spectroscopy in the study of material structure. High-power mid-infrared (3.5 lm) LD in infrared countermeasures, infrared illumination, laser radar, atmospheric window, Wide-ranging applications such as free space communication, atmospheric monitoring, and chemical spectroscopy.

Optical components for mass production optics

February 12, 2019 by zengbin  

The production of semiconductor procurement high efficiency optical windowcomponents on silicon wafers has long been a goal of the electronics industry, but it has proven to be challenging. Now, researchers at the A*STAR Institute have developed a new manufacturing method that is cheap, simple, and scalable. Hybrid silicon optics combine the luminescent properties of III-V semiconductors such as gallium arsenide and indium phosphide with proven silicon fabrication techniques. These optical components have attracted considerable attention because they can integrate photonic and microelectronic components into a single silicon chip, resulting in inexpensive, mass-produced optics. They have broad application prospects, from short-range data communication to high-speed, long-distance customizable Anti-Reflection (AR) Coated optical window transmission. However, in the current production process, optical components are fabricated on separate III-V semiconductor wafers and then individually aligned to each silicon device - a time consuming and expensive process that limits the optics on the chip. Quantity. To overcome these limitations, DorisKeh-TingNg from the A*STAR Data Storage Institute and colleagues have developed an innovative method for producing hybrid micro-cavities for mixed III-V semiconductors and silicon-on-insulator (SOI) films. This greatly reduces the complexity of the manufacturing process and makes the device structure more compact. Oblique-angle scanning electron microscope image of a 500 nm diameter microdisk. Image courtesy of A*STAR Data Storage Institute “It is very challenging to etch the entire cavity,” Ng said. “Currently, there is no single etching recipe and mask that allows etching throughout the microcavity, so we decided to develop a new method.” By first attaching the III-V semiconductor film to a silicon oxide (SiO2) wafer using an SOI interlayer thermal bonding process, they create a strong bond, eliminating the need for an oxidant such as a piranha etchant or hydrofluoric acid. . Moreover, by using a dual hard mask technique to etch into the microcavities of the desired layer, they eliminate the need to use multiple overlay lithography and etch cycles - a challenging process procurement high efficiency optical lens parts. Ng explained: "Our approach reduces the number of manufacturing steps, reduces the use of hazardous chemicals, and the entire process requires only one lithography step to complete." For the first time, this work introduces a new heterogeneous core configuration and integrated fabrication process that combines low temperature SiO2 interlayer bonding with a dual hard mask, single lithography pattern. Ng said: "This process not only creates heterogeneous nuclear devices, but also greatly reduces the difficulty of the manufacturing process, and can be used as another hybrid microcavity in the research field."

The correct choice of cutting blades

January 24, 2019 by zengbin  

First, the occasion of use When we choose the cutting piece, we first choose the right one depending on the occasion of the cutting piece. Because the performance requirements of the cutting piece are different for different occasions, it is important to choose a reasonable cutting piece. We need to choose the China cutting disc for metal according to the occasion we use, which can increase the safety factor, improve work efficiency and reduce our use cost. Second, the choice of cutting blades for ordinary cutting blades Ordinary cutting machines usually refer to fixed cutting machines, cutting machines with a power of low price disc for metal is required to have a certain rigidity. Therefore, under normal circumstances, we will use a cutting piece with a thickness of 3.8 mm. Shandong grinding wheel manufacturer: inspection before grinding machine 2018-04-14 09:25:07 Longshun Mill Industry Co., Ltd. Read 1) Check if the fasteners are loose, if necessary, tighten them. 2) Focus on checking whether the grinding wheel has cracks and replace it if necessary. Inspection method: Tap the grinding wheel with a wooden stick to make a crisp sound. 3) Move the grinding wheel by hand to observe whether the grinding wheel is flexible and light, and listen to the sound. 4) Check if the direction of rotation of the grinding wheel is correct, and the grinding debris will fly downward from the grinding wheel in the correct direction. 5) Start the power supply. If the vibration and noise are abnormal, stop it immediately and hang it up, and let the maintenance worker overhaul. 6) Check that the gap between the outer circle of the grinding wheel and the workpiece carrier should be ≤ 3mm. 7) Check if the grounding of the grinder is intact

Rapid development of cutting sheet processing industry

January 23, 2019 by zengbin  

Casting workpieces can be divided into two categories from materials: ferrous metal castings such as grey cast iron, ductile iron, alloy cast iron, and cast steel. One type is non-ferrous metal castings such as cast copper alloys, cast aluminum alloys; with the development of the mechanical industry, the performance of various casting alloys has been greatly improved, and the machining of castings is increasingly using high-speed cutting and drying. Cutting, high-speed cutting and 14 inches cutting disc are the fastest growing cubic boron nitride cutting discs and diamond cutting discs. Diamond cutting grades are available in CDW10, CDW20, CDW30 for finishing, medium finishing and roughing. Casting as a blank forming process, the performance of castings is mainly determined by casting. With the development of the machinery industry, various high hardness, high strength, high wear resistance, corrosion resistance and high temperature resistance of castings are becoming more and more. Processing and cutting sheets also exhibit high hardness, high speed machining, high efficiency and high precision with the processing requirements of these castings. CBN and PCD cutting sheets provide the basis for cutting blades for difficult-to-machine materials and high-speed cutting. For example, the BN-K1 new grade cutting piece is used to rough-process large-scale castings of high-chromium anti-wear white cast iron and heat-resistant and corrosion-resistant high-cobalt chromium-molybdenum casting alloy. The BN-S30 grade is used to tell the processing of gray cast iron, and the BN-K20 high speed fine car is used for high strength ductile iron. The cast aluminum alloy was processed at a high speed of 1000 m/min or more using a CDW10 grade PCD cutting piece. With the mass production and high performance requirements of castings, machining is also becoming more and more inclined to high-speed cutting and dry cutting; in the 21st century, new machine tools and numerical control technology and new material cutting sheets will be more and more popular, helping casting and machining. . CBN and PCD cutting discs are pioneers in the localization of high quality cutting disc supplier, dedicated to hard material processing and high-speed machining. Its "tailor-made" service, professional, efficient and fast-responding service, provides complete cutting blade products and solutions for high-hardness cutting and high-speed cutting.

Type of bonding agent for diamond grinding wheel

January 21, 2019 by zengbin  

Diamond wheel binders are mainly used for the bonding of abrasives, and there are many types of binders in diamond wheels. Firstly, we divide diamond grinding wheel binder into inorganic binder and organic binder. The inorganic binder can be divided into ceramic binder, metal binder and rhombohedral binder, and organic binder can be divided into resin binder. And rubber binder. Below, Terry Tools will give you a detailed introduction to the types of bonding agents for diamond wheels. Resin bond: It has good elasticity and polishing effect. After forming the fiber cutting disc Chinese supplier, it still has good self-sharpness, is not easy to block, has less dressing, and has higher grinding efficiency, lower grinding temperature, and ground surface. The finish is high, so the application range is very wide. Combined with diamond abrasive to form a resin bond diamond grinding wheel, often used in cemented carbide workpieces, steel-based cemented carbide workpieces, and semi-finishing, fine grinding of some non-metallic materials; combined with resin binder to form resin bond cube Boron nitride grinding wheel, mainly used for sharpening of high vanadium high speed steel tools and semi-finishing and fine grinding of tool steel, die steel, stainless steel and heat resistant alloy workpieces. However, the resin binder has poor grip on the abrasive and poor heat resistance, which leads to large wear of the grinding wheel under high temperature grinding, especially when the heavy load is ground, and is often improved by using a metal coated abrasive. . Ceramic bond: This bond has a stronger bonding strength to the abrasive than the resin. After the grinding wheel is formed, the work surface has good chip resistance, so it is not easy to block, the cutting is sharp, the grinding efficiency is high, and the amount of thermal expansion is small, and the processing precision is easily controlled. These characteristics are favorable for the smooth progress of the grinding process. In the shaping and dressing of the durable cutting off wheel, it is relatively easy to operate, and is generally used for rough grinding, semi-finishing, and large-scale forming grinding. Metal bond: contains two major categories of bronze bond and electroplating bond. Electroplating bonding agent is a bonding agent with higher bonding strength. Generally, single or multi-layer abrasive grains are plated on a metal substrate by electroplating. The number of abrasive grains per unit area on the working surface of the bonding agent grinding wheel is several The binder is much higher and the abrasive particles are exposed to the surface of the binder, resulting in sharp cutting and high grinding efficiency.

How to improve the workpiece rotation speed during cbn grinding wheel cutting

January 18, 2019 by zengbin  

When the cbn grinding wheel is used for cutting, the workpiece rotation speed is increased, and the workpiece size is poorly discontinuous. The hardness of the selected grinding wheel is too large: replace the grinding wheel of appropriate hardness. The 14 inches cutting disc has a shock pattern on the outside. The feed is too large: reduce the feed. The grinding wheel is hard: reduce the hardness. Speed up the dressing. The grinding wheel is not flattened: the grinding wheel is re-trimmed to the machine: to check the vibration of the machine and the surrounding environment. The continuity of the common workpiece size is relatively poor. The hardness of the selected grinding wheel is too low: replace the grinding wheel of appropriate hardness. Long-life end face grinding resin cbn grinding wheel. After grinding, the surface roughness of the workpiece is relatively poor. The speed of the workpiece is too slow: speed up the workpiece. The coolant is not well filtered: check that the filter system that adjusts the coolant is normal. The feed rate is too large: the feed rate is appropriately slowed down. The grinding wheel speed is too low: adjust the rotation speed of the grinding wheel. Grinding wheel is not in place: adjust or replace the cbn wheel dresser to re-trim. The high quality cutting disc supplier particle size is not matched: replace the matching grinding wheel. The unique properties of superhard materials have been exploited from time to time, with the advancement of science and technology in China. The technical level of super-hard data products has been improved from time to time, and the application fields have expanded from time to time. The super-hard data products industry has become an indispensable part of the national economy and national defense construction. With the increasing naiveness of cbn grinding wheel technology and the rapid take-off of China's economy, the country has accumulated more and more progress in the manufacturing technology of cbn grinding wheel tools, and has strong manufacturing capabilities.