Basic Knowledge of Photoelectric Sensors

Light Source and Light Receiving Element

Important components in the structure of photoelectric sensors are a light source of emitter and light receiving element of receiver. In general, a LED and laser diode is used for light source and a photodiode or phototransistor is used for light receiver.

A color of light has a relationship with a wavelength of electromagnetic radiation.
The human eye can perceive the wavelength of light from about 400nm to 700nm.
The majority of photoelectric sensors operate within the wavelength of visible light.

•