TRANSMISSION VS

TRANSMISSION VS. OPTICAL GLASS THICKNESS

USING OPTICAL GLASS DENSITY CALCULATIONS:

A COMPARISON OF HOYA'S TRANSMISSION CHARACTERISTICS

USING THE TRANSMISSION FOR A PUBLISHED THICKNESS TO CALCULATE

THE TRANSMISSION VALUES

FOR A HYPOTHETICAL THINNER SUBSTRATE OF THE SAME MATERIAL

The compendium presents the published nominal transmission values for optical glasses ranging in thickness from 5 mm to 10mm as indicated therein. It also contains the theoretical/derivated/calculated values for Hoya’s material if they were ground and polished to a 1mm thickness. These calculated values for a hypothetical thickness of 1mm were derived by Newport and were not published by Hoya nor was Hoya involved in the calculations, i.e., Hoya's material was selected by Newport to demonstrate the results of varying the thickness of a given material.

Hoya’s Optical Glass material was selected to demonstrate what the theoretical shift would be if the material was ground and polished to a 1 mm thickness. For example, Hoya has a material that is 5mm thick with the generic code of 551495 which starts transmitting around 90% at 360nm. If the same piece was ground and polish to a 1mm thickness, the 90% transmission point shifts down to around 332 nm. Therefore, one could theoretical move the 90% transmission point any where between 332nm and 360nm by adjusting the thickness between 1 mm and 5mm. A similar theoretical shift would occur if the other manufacturer’s material had been used in the calculations.

By using logarithmic calculations and the material absorption characteristics, the user may have an opportunity to select certain optical glass materials to function as long pass filters in areas where the standard optical filters are not available.