The explosion of digital technology in the late 1990s began what came to be known as the information age. An important change that was made possible by digital technology was the switching of many kinds of communication from wired devices to wireless devices. Two types of wireless devices have come to the forefront during the digital age: radio-frequency (RF) devices and infrared-emitting (IR) devices.

IR devices are used mainly for indoor applications. In order for an IR device to work, both the transmitter and receiver must "see" each other. The television remote controls that most Americans have in their homes are IR devices. Several companies developed IR devices that do more than change the channel of the television. IR devices can transport video, audio, and data, and they can control functions at amazing speeds.

The infrared light that IR devices use to transport data is long-wavelength...