When it is again exposed to a laser, the altered molecules emit Raman light, which can be read by a photo diode.

The microphotodiodes serve to modulate current pulses based on the amount of light incident on the photo diode.

The single pixel consists of a photo sensitive element (e.g. a photo diode).

The photo diode can do that.

The research commissioned by Mueller used a mannequin with a photo diode attached to the right eye.

The actual beam is measured by photo diodes.

The sun sensors are planar photo diodes that detect the intensity of incoming sunlight.

And at the other end is a receiving photo diode and no transmitter.

A more advanced system uses photoelectric cells (also known as photo diodes), devices that generate a current when exposed to light, to detect the position.

As the disc turns, the light shines through the holes onto the photo diode.