tech tip icon

To meet increasing industrial demands, Master Bond has developed a number of systems that display outstanding optical transmittance. Optical transmission refers to the ability for light to be channeled through a material. This property is particularly important for fiber optic, opto-electronic and photonic applications.

Superior transparency, even in sustained high temperature conditions, is one of the most essential characteristics of an optical adhesive. By measuring a sample’s transmission spectra, manufacturers can detect an adhesive's level of radiation absorption as a function of wavelength. Master Bond has developed EP30LV-1, a two component epoxy compound for fiber optics which exhibits outstanding spectral transmittance over 97% (0.35 – 1.1 microns).

Optical Transmittance

A system must also exhibit a refractive index ranging from a low 1.43 to a high 1.61.The index of refraction is defined as the ratio of the velocity of light in a vacuum to the velocity of that light in a given medium. Most epoxies have refractive indexes ranging from 1.50-1.57. Master Bond’s UV15-7 is an excellent UV cured adhesive with a refractive index of 1.55 and exhibits a desirable combination of properties including durability, roughness and thermal shock resistance. The UV15-7 polymeric material can be employed over the wide service temperature range of -60 to +300°F. Specialized systems are also available for high temperature resistant and NASA low outgassing applications.

Translucent adhesives exhibit attractive performance features in addition to given properties such as appropriate viscosity and durability in adverse conditions. Optical adhesives are the preferred solution for LEDs, circuit boards, protective coatings on displays, LCDs and lasers and may be used as bondings, coatings or encapsulations.