Narrow bandpass filters are designed to isolate a narrow region of the infra-red spectrum. Narrow band pass filters have bandwidths (measured at half-peak transmittance levels) less than 6% of the centre of wavelength value. Usually blocked outwith the region of transmission.

Bandpass filters are designed to isolate a relatively wide spectral band. They are classified by having bandwidths (measured at half-peak transmittance levels) between 6% and 13% of the centre wavelength value. Usually blocked outwith the region of transmission.

Wide bandpass filters are designed to isolate a very wide spectral band. They are classified by having bandwidths (measured at half peak transmittance levels) greater than 13%. Usually blocked outwith the region of transmission. This type of filter is particularly useful for isolating the 3-5um or 8-12um atmospheric windows and finds widespread use in thermal imaging/human body sensor applications.

Long Wave Pass filters (also referred to as edge filters) are constructed from stacks of thin layers. They are distinguished by a sharp transition from a zone of rejection to a zone of transmission. The rejection region extends to below 0.3um and the transmission region typically extends to greater than twice the wavelength of the edge position.

Neutral density filters are manufactured on a custom basis with optical densities from 0.1 to 2.0 (79% to 1%). The majority of neutral density filters offered are manufactured with a metallic coating which attenuates incident light by both reflection and absorption.

Capabilities in anti-reflection coatings range from single layers to advanced high efficiency multi-layer coatings. These coatings can be applied to windows, lenses or customer supplied substrates.