Operates at the same wavelength as the infrared detector module you select. The beam angle is important. Some LEDs provide very narrow beam angles, and are best suited for applications such as detecting objects in a narrow path or precision focusing of emitted IR energy. If you want maximum coverage, and detection, select an LED with a wide beam angle. Because of this wave motion, each different color has its own unique wavelength.
Light wavelengths are very short, and are expressed in nanometers .
The abbreviation for this is nm . When you examine a data sheet for a particular infrared LED, you'll see its wavelength expressed as 940nm or 880nm. To ensure optimal operation of your infrared system it's very important to match the LED characteristics as closely as possible to the infrared detectors. You download the data sheet for this LED from the manufacturers web site and notice that the LED operates at 940nm. This is how far off this particular infrared detectors sensitivity will be with just a simple mismatch of components, and shows the importance of selecting the correct components for your infrared remote control system for maximum effectiveness.