Anti Reflection Coatings Alleviate Ghosting in Beam Splitters
July 14, 2010
Anti Reflection Coatings help to alleviate ghosting problems experienced in beam splitters.
A beam splitter is an optical device used to split incident light entering it by allowing approximately half of the light to transmit and continue along the originating path while reflecting the remaining light along a separate path. In this way the beam splitter provides two identical beams or images at about half the strength of the incident light.
Ghosting occurs in a beam splitter when a small percentage of the incident light reflects off the secondary surface of the beamsplitter instead of being transmitted out of the beamsplitter. As the incident light approaches a 45 degree 50/50 beamsplitter half of the light will reflect and half will transmit as intended. Once the transmitted light enters the beamsplitter, it transmits most of that light out of the other side of the beam splitter along the intended path but also reflects a small portion of that light. This causes a dim ghost image to accompany the initial reflected light.
Anti Reflection coatings reduce the amount of light that is unintentionally reflected by the coated surface. In this particular situation, the secondary surface of the beamsplitter is coated with an anti reflection coating in order to drastically reduce the amount of light that is being reflected by that surface. This helps to promote the integrity of the two divergent images.
Abrisa uses cost effective techniques for creating quality anti reflection coatings and beamsplitter coatings. For more information about how anti reflection coatings on beamsplitters can help your application, please call us at 877.6.ABRISA (877.622.7472) or email us.
Anti Reflection Coatings and Chemically Strengthened Glass used in Touch Screen Displays
May 26, 2010
The first day of exhibits at SID 2010 (Society for Information Display) brought to the forefront the advances being made in touch screen technology and how anti reflection coatings and chemically strengthened glass greatly benefit these cutting edge devices.
Touch screen displays offer a wide variety of challenges for developers from dealing with the comparative light levels of the device and the environment to addressing concerns regarding the scratch and damage resistance of the display.
Comparative light level differences between the device and the environment present an ongoing dilemma for developers. As a device is used in a dark environment, very little light emission is required to create an appropriately readable display. As soon as you take the device outside in the bright afternoon sun however, things look a bit different. Excessive environmental light reflecting off the display has a tendency to drown out low levels of light emission. One somewhat effective solution is to ramp up the amount of light the device emits, but will then drain the battery of the device more quickly. Another way to help alleviate this particular problem is to coat the display glass with an anti reflective coating. This greatly increases the readability of the device without reducing the battery life. In combination with an anti reflection coating some developers have opted to use light sensing to determine when environmental light is elevated and throttles up the amount of light the device emits, then when the environmental light is reduced again, from walking indoors for instance, the device throttles light emission levels back down. Between these two solutions touch screen displays are effectively dealing with glare problems experienced in outdoor situations.
Scratch and damage resistance is another concern when dealing with touch screen displays. These devices are intended to be touched, and beyond that they are intended to have fingertips dragged along their surface. If the potential for scratches and other damage to the display stopped with sliding skin contact then that would be relatively simple to address, but there are other concerns with finger contact on a touch screen display. Fingernails, rings and gloves are just a starting point for possibly damaging contact. One way to address this particular problem is to chemically strengthen the glass used in the display. Glass undergoing the chemical strengthening process can become upwards of five times harder, and thus more resistant to damage. In addition to this is the option of using a scratch resistant thin film coating that will further protect the display from scratches. There is another type of damage that these solutions may help prevent, and that is from cleaning cloths as these displays are subjected to skin oils.
Displays need to be cleaned now and then. Even displays that are not intended to be touched still collect dust and unintended particles that degrade the image being displayed. Oils from skin contact are a particularly prominent issue when it comes to touch screens however, and as such they need to be cleaned regularly. One way to help reduce the amount of cleaning chemicals and potentially abrasive contact from cleaning cloths is to utilize an oleophobic coating. This thin film coating will encourage skin oils to bead up and not adhere to the display. As such it is easier to remove the oils with a cleaning cloth and fewer cleaning chemicals are then needed to ensure cleanliness of the display.
For more information about Abrisa’s Anti Reflection Coatings and Chemically Strengthened Glass please call 877.6.ABRISA (877.622.7472), email us or visit our booth at SID 2010 (booth 500).
Hot Mirror Applications for use with Digital Photography
July 8, 2009
Front Surface Mirrors for Optics
July 1, 2009
AR Coatings
May 28, 2009
AR coatings are often critical components in optical systems with multiple lenses, or other optics where the maximum possible light energy is needed. AR coatings help to produce brigter images. They also reduce the intensity of ghost images which are sometimes produced in optical systems by multiple reflecting surfaces.
Full story…. 
What is a Hot Mirror
May 20, 2009
Welcome to the new Abrisa news section.
October 28, 2008
Greetings, and welcome to the new Abrisa news section. Here you will find many new articles regarding our products and services including Dichroic coatings, EMI/RFI shielding, Glass Fabrication and more. If you have any questions and comments for us, please contact us.
If you have any projects we can help you with, please contact one of our sales staff or submit an RFQ and our staff will get back to you.
