MWIR and LWIR infrared lenses for thermal imaging systems.

An MWIR lens works in the 3–5 μm band and is normally matched to a cooled detector with a cold shield. An LWIR lens works in the 8–12 μm band and is most often matched to an uncooled microbolometer. The band, detector type, F-number practice and typical focal-length range all follow from that choice.

Start from the LWIR 8–12 μm family. Convert the required coverage into a horizontal field of view, then select the focal length from the detector active area. That array is 7.68 mm wide, so a 15 mm objective gives roughly 28.7° horizontal field, 25 mm gives roughly 17.5°, 50 mm gives roughly 8.8° and 100 mm gives roughly 4.4°. Confirm the exact value against the detector datasheet and the final optical design.

The refractive index of infrared materials and the dimensions of the housing both change with temperature. A passively athermalized objective compensates mechanically so that focus stays stable over the operating range without user adjustment. Ask for the stated focus-shift limit or the acceptance test on the approved sample.

Yes. The reference range includes a 25/50 mm dual-FOV LWIR assembly and two motorized MWIR continuous-zoom assemblies, 15–300 mm and 18–275 mm. Dual-FOV suits two discrete viewing tasks; continuous zoom suits operators who need to move smoothly between them.

Common materials include germanium, silicon, chalcogenide glass, zinc selenide and zinc sulfide, selected by band, environment and cost. Broadband anti-reflection coating for the working band is normal practice, with diamond-like carbon or hard carbon on exposed front surfaces for harsh environments.

Send the detector type, resolution and pixel pitch; the spectral band; the required focal length or field of view; the F-number and any cold-shield data; the focus architecture; the working distance; the envelope, mount, mass and temperature range; and the prototype and annual quantity. Attach the detector datasheet where possible.

Yes. The cold-shield geometry is part of the optical interface, so send the cold-stop diameter, its distance from the detector plane and the dewar drawing. These values are confirmed together with the focal length, F-number and back focal distance before the quotation is issued.

Yes, for qualified B2B projects and by appointment. We confirm the product route, the selected facility, the visit scope, the equipment and processes to be reviewed, the records requested and the attendees before scheduling. TUOLAN TRADE coordinates sourcing; manufacturing is performed by the selected and approved production facility.