An object at a temperature above absolute zero emits thermal radiation, and the intensity and spectrum of the emitted radiation depend on the object’s temperature. Infrared thermal detectors can collect this radiation and deduce the temperature from the measurement results based on Planck’s radiation law. The technology has seen significant development and has been widely adapted in various domains, such as healthcare, food safety and quality assessment, pest detection, and surveillance. In everyday applications, thermometers measure the average temperature in the field of view, which can be used for example for safe remote body temperature measurement. Thermal cameras have the further advantage of providing a 2D heatmap, which can be applied in non-destructive mechanical and electrical testing applications to identify malfunctioning parts, detect subsurface defects, or monitor materials during heating and cooling processes, based on hotspots and temperature gradients.

In this webinar we demonstrate how to model infrared thermal detectors in OpticStudio. We will first discuss how to describe thermal radiation accurately by blackbody sources. Then we show how to simulate the temperature calibration process of thermal detectors via the ZOS-API to enable not only qualitative analysis, but also accurate temperature measurements by these devices.