Collimators
Collimators are optical systems used to imitate standard targets placed in "optical infinity" (very long distance). The collimators are used for projection of image of reference targets into direction of tested imagers. According to type of optical elements used in design, collimators are divided into two groups: reflective collimators and refractive collimators. Reflective collimators due to their wide spectral range are almost exclusively used in systems for testing thermal imagers and are also preferable in systems testing TV cameras, SWIR imagers, laser systems or multi-sensor surveillance systems. Refractive collimators are mostly used in systems for testing night vision devices or TV cameras working in visible/near infrared range.
