Photodetectors have become the most ubiquitous kinds of technology employed in many fields today. They include simple gadgets that automatically open doors to receivers on VCR and TV remote controls. Other examples of photodetectors are photodiodes in the fiber optic connection, CCD in the video camera and the massive arrays utilized by astronauts to detect radiation in other parts of the universe. Photodetectors like APD photodetectors are available in a large variety of gadgets utilized in entertainment, industry, research and commerce. Actually, the industry of photodetector design and application has increased to the point that some practitioners have a comprehensive overview.
An APD photodetector comprises any gadget that registers photons with frequencies that surpasses that of radio waves. In this post, we look at some of the applications that utilize photodetectors. The applications fall into 2 major categories, remote sensing and communication. In different forms of remote sensing, radiation is single, transferring information about a scene or object. In communications, the radiation serves as the carrier of the encoded signal.
Even though the detectors utilized in fiber optic communication are invisible to the phone users, those available in common remote control gadgets are obvious and found in almost all homes. While the photodiodes sensitive to infrared wavelengths are standard, the requirements are far laxer for fiberoptic gadgets because data transmission rates are lower. This means a smaller amount of data is conveyed. However, even remote control devices are improving in sophistication. For instance, wireless mouse gadgets for computers use detectors that measure the comparative strength of the signal to define the mouse position and orientation.
Security and Safety
The simplest forms of remote sensing apps entail the detection of the absence or presence of a condition or object for security and safety monitoring. Typically, these applications utilize photoconductors, the most rugged or and cheapest detector technology. A good example of such an application is IR sensitive movement detectors used in home security units. Other examples that have been developed recently include automotive uses like a collision detector that monitors situations in the driver’s blind spot. There is also a passenger detector that defines when to activate the airbag.
Process Control
Another area of sophistication comes in process control applications. This is where photodetectors like the APD photodetector are widely used. In most cases, the devices might be something simple like position sensors that check that a workpiece is properly placed or offer a response for robotic units. However, some systems require comparison of radiation intensity at various wavelengths which need the use of accurately repeatable detectors like photodiodes. For example, in a recycling plant, the natural fluorescence of some plastics can be utilized with optically filtered photodetectors to sort various materials. On the other hand, spectroscopic tests can differentiate various kinds of glass.
