Unaxis Optics, a manufacturer of thin film optical components, announces new dichroics filters/mirrors specifically optimized for LED applications. These LED ColorDichroics™ efficiently reflect and transmit random polarized light from individual high brightness power LED sources of different colors.

Applications of LED ColorDichroics™ range from projection display illumination optics to various uses in solid state lighting and instrumentation. In recent years, light emitting devices (LED) used as novel light sources have seen dramatic technical improvements resulting in very high brightness. They have become commercially available in all primary colors of red, green, and blue as well as other colors such as cyan and yellow. The principal advantages of these new light sources are their specific and narrow spectral emission characteristics and their extremely fast switching capabilities. These advantages make them excellent illumination sources for application in projection display systems, enabling much more saturated colors and very high contrast.

LED ColorDichroics™ are cost-efficient for merging LED light beams. The inherently random polarized light characteristics of LEDs make them very suitable sources for microdisplay devices based on light engine architecture that do not require polarized light (DLP®* and others). Since most of these light engines are based on single microdisplay chip architectures, the light from the three different primary color LEDs of red, green and blue has to be merged into one common beam. LED ColorDichroics™ provide a very cost effective and versatile solution for reflecting and transmitting the light from the different color LED sources in =order to combine the individual light emissions into one single light beam.

LED ColorDichroics™ are usually arranged at 45° relative to the orientation of the different LEDs. The spectral characteristics of the LED ColorDichroics™ are specifically optimized for high efficiency and low optical loss with random polarized light. The spectral separation between highly transmissive and highly reflective wavelength ranges is reduced compared to the typical spectral characteristics of standard dichroic filters/mirrors for random polarized light. Even better spectral characteristics can be achieved with LED ColorDichroics™ that are optimized for applications with an angle of incidence (AOI) onto the filters smaller than 45°. Excellent stability, high reproducibility in mass production LED ColorDichroics™ are manufactured with Unaxis Optics’ patented optical sputter coating technology. This process provides filter coatings with excellent optical and mechanical stability, even under widely varying environmental conditions. The high degree of manufacturing reproducibility allows mass production of the dichroic filter coatings within very narrow tolerances. This results in highly consistent optical performance of customized LED ColorDichroics™ in their specific applications.

LED ColorDichroics™ are coated on flat borosilicate substrates with a standard thickness of 0.7mm and 1.1mm. Other glass types as well as other thickness values are available upon customer request. LED ColorDichroics™ are manufactured to customer specific sizes with narrow dimensional tolerances.

Unaxis Optics’ internal coating engineering and optical design capabilities ensure top quality and performance of LED ColorDichroics™ as well as broad technical support in customer design and applications. Together with Unaxis Optics’ Silflex™ coating based LightTunnel™ integrators, these new LED ColorDichroics™ enable Unaxis Optics to offer optimized component solutions for novel projection display systems, for solid state lighting applications based on LED light sources, and for other specific instrumentation applications.