Normal glass is generally clear and transparent. But while that’s true, reflection can make viewing things through it difficult, and anti-reflective glass is used in its place. This type of glass reduces the amount of light that can bounce off its surface, making it great for situations that require clear viewing. So, what is anti reflection glass and where do you need it?
What is Anti Reflective Glass?
Anti reflective glass, which is also commonly shortened to AR glass, is a special type of glass that has been coated to reduce light reflections. As a result, it appears more transparent and makes the view through it clearer than that of normal, uncoated glass.
Non reflective glass is made by coating normal glass — usually low iron glass — with a special thin, transparent material. This material must offer a clear view. On the other hand, the coating must provide a refractive index that is different from that of the glass substrate.
A single layer may be used to make anti-reflective glass film, or it can be multiple layers (up to 10 or more) with varying degrees of thickness. Most often, several layers are used. These offer enhanced performance when it comes to reducing reflections, ensuring a transparency level that make the glass almost invisible.
How Does Non Reflective Glass Work?
An anti reflective glass sheet works by offering more than one reflection interfaces. These are air to film boundary and the film to glass boundary. When incident light hits the glass, part of it is reflected by the coating, and another part the glass surface, but with a change of phase. This is what happens then:
- The change of phase causes the wavelengths that get reflected to interfere destructively.
- This cancels them out, eliminating reflections that your eyes would see if the glass was uncoated.
- The result is a crisp, clear view through the glass, clearer than what normal glass can produce.
- In terms of figures, anti reflection glass can reduce reflectance to as low as less than 1% and offer up to 99% transmission.
- Compare that with normal glass that only allows up to 92% transmission and about 8% reduction in reflections.
- Using multiple layers of the AR film creates even more reflection interface (coating to coating), enhancing the amount of interference.
Note that even when needed tough for demanding conditions, strengthened AR glass can achieve a reduction of up to 3% of the reflected light, allowing for both enhanced visibility and strength.
Tough AR glass can be heat or chemically-strengthened glass such as gorilla glass, or it can be heat treated glass with other properties such as anti-smudge, UV isolation, and so on.
Anti Reflective Glass Coating
Antireflective glass coating is the optical layer that, when applied to glass or other substrate, helps decrease the amount of reflections. A single or several coatings may also be used, depending on the required performance. Multiple coats are more effective, since they refine the antireflective performance of the glass.
Anti Reflection Coating Principle
The anti reflection coating principle is based on how light interacts with different types of light transmission media. The coating, having a specific thickness that’s different from that of the glass, interacts with light to cause destructive interference with the wavelengths that are being reflected.
By using multiple coatings, most reflections are eliminated. The number of coatings mostly depends on the required performance of the substrate, or the wavelengths that need to be reflected, both in the visible and invisible parts of the spectrum.
Manufacturers may use different methods to apply anti-reflective glass film, such as sputtering, spin coating, or vapor deposition. It’s good to note that coatings of AR glass are transparent and do not introduce any coloration to the glass, which means optimum light transmittance among other benefits.
Types of Anti Reflective Coatings for Glasses
Different types of anti-reflective coating for glasses are available. Mostly, these are oxides such as silicon dioxide and titanium dioxide that, in addition to being transparent, can offer varying degrees of optical properties.
Other compounds, such as magnesium fluoride and yttrium fluoride, are also used, especially if a less costly coating is required. Anti-reflective glass coatings are also commonly classified into broadband coatings, V coatings, and.
Broadband coatings offer anti reflection across a range of wavelengths, while V coatings are called so for the characteristic shape of their refractive indices. These are are designed to offer antireflection for a smaller range of wavelengths.
Benefits of Anti Reflective Glasses
Anti-reflective glasses benefits range from visual appeal to the ability to reduce glare and other advantages. When used in different applications, it offers a higher transparency than normal glass, with light transmission that surpasses 98%.
This type of glass also offers a higher color rendering index of up to 99, owing to the increased transmission. Objects appear more real and in their true colors, just they would without any glass. By reducing reflections, AR glass allows pleasant viewing that also doesn’t tire the eyes.
When used on store fronts or other display structures, for example, AR glass makes items clearer to view and with enhanced contrast in their colors. On optical devices, anti-reflective glass increases their effectiveness, enabling clear views.
What is Non Reflective Glass Used For?
Non reflective glass, which is another name for anti-reflective glass, is u123rsed in many different industries, where it offers clear, unobstructed views by reducing the amount of wavelengths that get reflected back. Common applications include the following:
- Anti reflection display glass for retail storefronts and car showrooms
- For electronic product displays such as smartphone screens
- Non reflective glass for automotive windshields
- Viewing windows and the lenses of optical devices
- Optical sensor cover glasses
- Anti reflection glass windows for both residential and commercial buildings
- Museum display cases
- As viewing glass for use in zoos and sports facilities
- Anti-reflective glass for eyes
- Non reflective glass for picture frames
- Digital signage glass
- Anti-reflective glass for photovoltaic panels
- To protect heritage sites and structures without obstructing views
Anti-reflective glass plays a crucial role in many different industries and applications, from storefront displays and phone screens, to the display cases of museums and the viewing windows of optical instruments. In all these cases, the glass offers pleasing, unobstructed view that’s devoid of reflections, which makes it an indispensable product in a broad range of industries.