where Tsr — average coefficient of a transmission of light a crystal for the beams falling on limit of the section at an angle, smaller critical. transmissions of light falling normally to a surface is determined by Fresnel's formula
Except above-mentioned spheres of SID are involved in lighting. Application of SID for lighting is caused as it was stated above, high efficiency of transformation of energy, reliability of the design which is well developed on today's put SID manufacturing techniques with various parameters of a luminescence.
As material for polymeric sealing of light-emitting diodes the epoxy compound on the basis of transparent pitch is in most cases used. The compound differs in very high svetopropuskaniye. Storage of samples of a compound at a temperature of +70-80 °C practically does not lead to deterioration of a svetopropuskaniye. Decrease in a svetopropuskaniye starts being observed at long storage at a temperature of +100 °C and above, and the greatest absorption of light is observed in short-wave part of a visible range. Dye introduction (for example, red) causes sharp increase in absorption of short-wave light, but practically does not influence absorption of light of long-wave part of visible range. Introduction of dyes promotes increase of contrast of a luminescence due to absorption of a diffused light of surrounding space.