An electronic device called an infrared (IR) transceiver is able to communicate data using infrared light. IR transceiver units can both transmit and receive information. One of the most widely used is Infrared Data Association (IrDA), which is commonly found on devices such as laptop computers and mobile phones. IrDA infrared transceivers have become more effective since first being introduced in 1993. Improvements on the original IrDA protocol now allow for rapid transfer of files such as pictures and music.
IR transceivers operate by sending rapid pulses of light on the infrared spectrum. This means that the pulses are not visible to the human eye, but can be detected by other transceivers. All devices that share a protocol are programmed with the same universal code. When IR pulses are received, this code is used to interpret the message, similar to a flashlight being used to send Morse code.
Two main components are found inside an IR transceiver unit. An infrared light emitting diode (LED) is used to produce infrared pulses, while an infrared detector is able to sense incoming infrared signals. Some advanced IR transceivers use infrared laser diodes in place of LEDs. This increases the range of the IR signal, but reduces the width of the detectable beam.
The standardization of IR transceiver protocols allows many different devices to share data quickly. For instance, many personal data assistants (PDAs) and cell phones feature IrDA transceiver modules. Two people in the same room can simply point their devices at each other in order to transfer messages or files. Infrared-enabled devices such as printers can also receive files through the air, eliminating the need for connection cables.
This approach to wireless communication does have several drawbacks. Light sources such as the sun can cause interference with communication. Additionally, IR transceivers are typically limited to direct line of sight communication, and cannot transfer data through walls or obstructions.
Typically less expensive than radio frequency devices, IR transceivers are also usually considered more secure. The pulses used for infrared data transfer are usually contained in a single room and do not escape to other areas. This reduces the chances of the signal being intercepted by eavesdroppers, and makes IR transceiver usage popular for low-range secure areas such as investment brokerage offices and military installations.