SCHOTT offers two main glass types as molded glass. The main workhorse (“St”) is usable for visible and NIR light. A second glass expands this range into the UV region (“UV”).
The following chart shows the glass transmittance spectrum for these glasses. All data indicated are for uncoated glass.
The usual glass type used for making window caps with solder glass technology is SCHOTT D263 glass. The transmission of this glass is shown in Figure 1 (“Pl”). For more information about this glass type, please visit this page.
For applications which have to extend into the UV and/or further into the infrared regions, we offer solder-sealed window caps with sapphire windows. This material provides a transmission band from 170 nm to 5500 nm. Sapphire with defined crystal orientation (i.e. c-cut) can be offered if the birefringent nature of sapphire is unsuitable for the application.
Data for the above-mentioned optical glasses are available here.
Coatings are applied using PVD techniques such as evaporation or sputtering. All of our coatings meet the requirements of MIL-C-48497 for durability. Transmission measurements are carried out using state-of-the-art spectrophotometers.
Due to the very accurate sphericity (typical specification: sphericity < 0.5 µm), it is very easy to calculate the effective focal distance (EFL) with respect to the back focal distance (BFL) of the ball lenses.
SCHOTT can also assist the customer in questions concerning how to effectively couple the light into fibers for data communication.