Anti Reflection Coatings Alleviate Ghosting in Beam Splitters

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.