Infrared was a form of radiation. Various species could see in infrared including Barabels, Chiss, Gran, Coway, Trandoshans, Chadra-Fan, Arkanians, Sakiyans, Nexu, and possibly Sullustans.
Technologies that used infrared included infrared scans and infrared motion sensors. In poorly lit areas, guards would activate devices that could scan with infrared optics.
The planet Alpheridies orbited the red dwarf star Aber that emitted energy mostly in the infrared spectrum. Because of this, the Miraluka gradually lost their ability to see.