Bandpass Filters
Thin film bandpass filters are optical elements that are designed to transmit a specific spectral band with high efficiency, while rejecting, by both absorption and reflection, all unwanted energy outside that region. The characteristics of the bandpass are controlled by multilayer dielectric coatings. Blocking is usually achieved with a combination of color filter glass and specially designed metallic films. The bandpass and blocking elements are laminated (epoxied) together to form a single unit and then edge sealed to prevent degradation due to moisture.
Standard
Esco provides standard bandpass filters that are designed for use at several common wavelengths. All models provide out of band blocking of better than 10-4. Two sizes are available: 0.5" and 1.0" diameter. Each filter is provided sealed in metal (aluminum) rings. These rings provide additional protection against degradation due to water absorption, as well as a more accurate edge that can often help in some mounting situations.
For a small charge, Esco will provide individual curves showing the actual transmission characteristics of any filter.