Laser sensors are used where small objects or precise positions are to be detected. They are designed as through-beam sensors, retro-reflective sensors or diffuse reflection sensors.
Laser light consists of light waves of the same wave length with a fixed phase ratio (coherence). This results in an important feature of laser sensors, that is the almost parallel light beam.
The result: Long ranges can be achieved thanks to the small angle of divergence. The laser spot which is clearly visible even in daylight makes the alignment of the system easier.