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 Hoyas material if they were ground and polished to a 1mm thickness. These calculated values
for a hypothetical thickness of 1mm were derived by
Hoyas 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 manufacturers 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.
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