Why Use Asphera For Flat Optic Needs: Some Information About Fluoride Windows, Sapphire Windows, and Alpha Quartz Windows

Vinh Tran • October 27, 2022

Asphera windows offers high-quality LiF windows, sapphire windows, and alpha quartz products. Our innovative products are perfect for both residential and commercial properties. With over 35 years of experience, we are dedicated to providing our clients with the best possible service and products.

LiF Windows


Lithium fluoride (LiF) windows have been used extensively in the past to allow diagnostics to be placed in the target chamber to observe the shock wave as it propagates through the different materials. However, these windows have a relatively low melting point and are easily damaged by the high temperatures and pressures generated by the shock wave.


Lithium Fluoride windows are commonly used for optical components (windows, wedge windows, lenses, prisms) in a wide spectrum band from vacuum ultra-violet to infrared and is transparent over the entire range of 0.140μm to 7μm.  It is used in fabricating first surface mirrors for CO2 lasers. The high transmission, low absorption, and stable physical and optical properties of lithium fluoride enable its use as a protective window over a wide range of environments, especially those that are chemically aggressive or erosive.


LiF crystals are optically isotropic and insoluable in water. They are resistant to most chemical reagents except for HF acids. The lithium fluoride window is often used as a viewport in high-pressure cells and reactors because of its resistance to attack by HF acid.  Its refractive index is the lowest out of all common infrared materials.  We offer micro-windows 1.6 mm diameters in thickness as low as 150um up to large 100 mm diameters and 50 mm thicknesses in (100) and (110) orientations.


Sapphire Windows


Sapphire windows are much more resistant to the high temperatures and pressures generated by shock waves, and can therefore be used to observe the shock wave more accurately.  Sapphire is a single crystal form of aluminum oxide (Al2O3) that is transparent over a wide range of wavelengths from the ultraviolet to the infrared. It has a high melting point and is resistant to attack by most chemicals.


Sapphire windows are used in a variety of applications where high strength, thermal resistance, and optical transparency are required. They are often used as viewports in high-pressure cells and reactors because of their resistance to attack by HF acid. Sapphire windows can also be used in high-temperature environments and in applications where a wide range of wavelengths need to be transmitted.


We offer sapphire windows in a variety of sizes and thicknesses. Our standard sizes are 1.6 mm in diameter and 150 um thick, but we can also provide larger windows up to 100 mm in diameter and 50 mm thick.


Alpha Quartz Windows


Alpha quartz is also being considered as a potential window material for this application due to its high melting point and resistance to damage.   Alpha quartz is a type of quartz that has a higher melting point and is more resistant to damage than other types of quartz. It is often used in high-temperature applications and in environments where a wide range of wavelengths need to be transmitted.


We offer alpha quartz windows in a variety of sizes and thicknesses. Our standard size is 1.6 mm in diameter and 150 um thick, but we can also provide larger windows up to 100 mm in diameter and 50 mm thick.


No matter what your needs are, we can help you find the right window material for your application. Contact us today to learn more about our products and services.


By Brian September 13, 2022
In the field of optics, aspheric lenses are gaining in popularity. This is because they offer many advantages over traditional spherical lenses. In this article, we will discuss what aspheric lenses are and how they differ from spherical lenses. We will also explore the benefits of using aspheric lenses in optical systems. What Is An Aspheric Lens? Aspheric lenses are lenses with a non-spherical surface. This means that the lens is not curved in a perfect circle. Instead, it has an irregular shape. The advantage of this is that aspheric lenses can correct for spherical aberration. Spherical aberration is a type of distortion that occurs when light passes through a spherical lens. This distortion can cause images to appear blurred. By using an aspheric lens, this distortion can be corrected. Aspheric lenses allow optical engineers to correct aberrations using fewer components than spherical optics since the former provides greater aberration correction than multiple surfaces of the latter. Given this, many spherical lenses may be replaced with smaller amounts of aspheric ones to achieve comparable or superior optical outcomes while reducing system size, simplifying the manufacturing procedure, and producing imaging lenses that are less expensive and outperform traditional spherical component assemblies. Costs And Benefits Of Using Aspheric Lenses. Aspheric lenses are not without their drawbacks, however. Aspheric lenses are more difficult to produce using conventional fabrication processes such as grinding and polishing since aspheric lens components are more intricate than spherical ones. As a result, aspheric lenses had not been widely used until recently. Nowadays, aspheric lenses may be created by the glass molding technique: a preform or near-net-shape glass is fed into heated molds within a molding machine, pressed between two mold halves, and then cooled and released from the molds. Glass molding is an efficient way to create complex shape accurate optical components at high efficiency. The cost of each lens produced using this method is less than that of standard aspherical manufacturing techniques, making it an excellent choice for high volume production. The issue with glass molding is that the high temperatures required to soften the glass can easily damage the mold, which shortens its lifespan. Furthermore, since it takes time to heat and cool down the mold, this process is inefficient. Consequently, for a long time there has been a demand for optical glasses that have a low softening temperature so they can be molded more easily. Glass material for molding has additional standards, such as transparency, scratch resistance, temperature stability in optical properties, and refractive index. Although plastic lenses are mass-produced at a lower cost, glass is better in terms of hardness, refractive index, light permeability, and stability to environmental changes such as temperature and humidity. In addition, it is important to provide a wide variety of glass materials for molding convenience to meet customers' needs. Asphere Manufacturing Methods There are four main methods of manufacturing aspheres: precision glass molding, precision polishing, diamond turning, and molded polymer aspheres. Precision glass molding is a process where a piece of glass is heated and then formed into the desired shape. This method is typically used for small batch sizes or when intricate shapes are needed. Precision polishing is a method where the asphere is created by grinding and then polishing the surface to achieve the desired shape. This method is typically used for larger batch sizes. Diamond turning, or Single Point Diamond Turning (SPDT), is a process where a diamond-tipped tool is used to cut the asphere into the desired shape. This method is typically used for small batch sizes or when precision is critical. Molded polymer aspheres are created by injection molding a piece of polymer into the desired shape. This method is typically used for larger batch sizes. Visit Here for more information about Aspherical Lens manufacturing methods. If you are designing an optical system, consider using aspheric lenses. They can provide superior performance at a lower cost than traditional spherical lenses. Do you have any questions about aspheric lenses? Leave a comment below and we will try to answer them!
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