Product Announcement from Edmund Optics Inc.
Our TECHSPEC® Germanium Plano-Convex (PCX) Lenses feature precision diamond turned surfaces making them ideal for a variety of infrared applications, including thermal imaging, infrared spectroscopy, and remote sensing. Available in 25 and 50mm diameters, the lenses are available uncoated. For custom infrared coating requirements, please contact our Sales Department.
Germanium is popular for its high index of refraction, broad transmission range, and rugged mechanical properties. With a transmission range of 2 - 16 μm and opacity in the visible portion of the spectrum, Germanium is well suited for infrared laser applications. However, Germanium is subject to thermal runaway, meaning that the transmission decreases as temperature increases; in fact, Germanium is nearly opaque at 100°C and completely non-transmissive at 200°C. Germanium's high density (5.33 g/cm3) should be considered when designing for weight-sensitive systems. The Knoop Hardness of Germanium (780) is approximately twice that of Magnesium Fluoride, making it ideal for infrared applications requiring rugged optics. Germanium is inert to air, water, alkalis, and acids (except nitric acid).
Plano-Convex (PCX) lenses feature a positive focal length and have one flat and one convex surface. They should be oriented with the plano (flat) surface towards the desired focal plane. They are ideal for collimation and focusing applications utilizing monochromatic illumination.