Which component is the detector that responds to infrared energy?

• A. Infrared Detection System
• B. Collimator Assembly
• C. Detector Array
• D. Video Indicator

Answer: (C)

The detector that responds to infrared energy is the detector array. In infrared imaging, the incoming infrared photons are collected by the optics and directed to the sensor, where the detector array—composed of many infrared‑sensitive pixels—absorbs the energy and converts it into electrical signals. Each pixel's signal reflects the amount of IR energy it receives, and together they form the infrared image.

The broader infrared detection system includes the detector array plus supporting electronics and cooling. The collimator assembly shapes or directs the light into a suitable form for the detector but does not itself sense IR energy. The video indicator is simply the display that shows the processed image, not the sensing element.