Infrared Transmitter and Reciever Kit
These infrared transmitter (emitter) and receiver (detector) from lite-on electronics operate at 940nm and work well for generic IR systems including remote control and touch-less object sensing.
Using a simple ADC on any micro-controller will allow variable readings to be collected from the detector.
The emitter is driven up to 50mA with a current limiting resistor as with any LED device. The detect is a NPN transistor that is biased by incoming IR light.