What are optical sensors?

Optical sensors refer to electronic detectors that are capable of converting light rays into electronic signals. These types of sensors are used to accurately measure the physical quantity of light and translate the measurement into readable data, which is then deciphered by a measuring device.  Optical sensors are typically contactless, capable of detecting and measuring light without establishing direct contact with the object. Consequently, they can be either internal sensors or external ones. 

Types of optical sensors

Optical sensors can be broadly categorised into different types. The major types can be described as:

Through-beam sensors

These types of optical sensors possess two separate components present at opposite ends, namely the transmitter and the receiver. The transmitter on one end projects light rays onto the receiver at the other end. Through-beam sensors are ideally used for large operating distances. 

Retro-reflective sensors

Typically, a sensor has two components; a transmitter and a receiver. The retro-reflective sensor, however, possesses an additional component called the reflector responsible for directing the light beam back to the receiver. 

Diffuse reflection sensors

In this specific type of optical sensor, both the transmitter and receiver remain in the same housing as well. The light beam is reflected by the object that needs to be detected and meets the receiver. 

Applications of optical sensors

Optical sensors have a multitude of applications. Some of the most common applications are in:

• Computers 
• Photocopy machines
• Motion detectors, alarm systems, and other security systems
• Automatic light fixtures
• Ambient light sensors
• Biomedical appliances