These infrared photodiodes are a proven light sensor in BEAM technology.
IR emitter and receiver in one package for close-range optical detection (sold individually)
If you want a really small, compact sensor to detect obstacles coming at your device, the 2-direction sensor kit is just the thing!
The Bittybot Micro Line sensor is a convenient way to build edge or line sensors, especially for MicroSumos!
BittyBot's Nano line sensor kit is a tight and tidy .95" wide pair of sensors for detecting white/black differences, like a line on a surface. Ideal for line-followers or sumo edge detection!
Looking for tiny proximity sensors? The BittyBot ProxDots are very small, and complete with IR modulated transmitter /receivers!
This sensor uses infrared technology to detect an object at 5mm by determining the difference between low reflective conditions (i.e. black) and high reflective conditions (i.e. white).
The Pololu IR beacon is a compact board that is used in pairs to allow robots to locate each other.
When the QTI sensor is over a dark surface, the reflectivity is very low; when the QTI is over a light surface, the reflectivity is very high and will cause a different reading from the sensor.