Laser diodes are semiconductor devices which closely resemble an LED (light emitting diode). How do they work?Laser diodes work in a very similar way to LEDs, however they create a laser beam at its junction instead. They create a very precise beam of light which is ideal for applications which require an accurate reading of data. They are also capable of a very powerful output, which can be determined by their optical output power.Laser diodes are available in a range of different packages, for example TO-38 and TO-56. What colours are laser diodes?The most common laser colours are red, blue and green. Their colour is described in wavelength, the same as an LED. Wavelength values are given in nanometers (nm). • Red is around 660nm• Blue is around 500nm • Green around 550nm. Laser diodes are also available with infrared (IR) light. Where are laser diodes used?• Fibre optic communications• Barcode readers• Laser pointers/pens• Disc reading & recording• Laser printing• Laser hair removal devices