Athermalised lenses for LWIR and thermal imaging

LightPath Technologies has introduced an athermalised f/1.3, 14.9mm focal length long wave IR lens assembly for thermal imaging with uncooled detectors in the 8-12µm wavelength range. The lenses are designed to be used as the primary optics in thermal imaging devices in a wide variety of applications, including homeland security, firefighting, predictive maintenance and driver’s vision enhancement systems in automobiles. The company states that these thermal imaging markets have a combined current estimated value of over $2.5bn.

This new lens assemblies incorporate LightPath’s 'Black Diamond' moulded chalcogenide infrared lenses, marketed as a low-cost substitute for high volume diamond-turned germanium and zinc selenide optics. The opto-mechanical design combined with the unique material properties of Black Diamond glasses provide athermalisation for temperature stability from -40°C to 85°C without adding additional cost. This specific design gives a 60° field-of-view when paired with a 15mm sensor with a 25µm pixel pitch.