A laser that emits three primary colors, red, green and blue is an RGB laser, the name coming from the three primary colors. These can be emitted in a single beam for all the three colors or a separate beam for each of the color. Through additive mixing which involves combination of the three basic colors at different frequencies, a number of several other colors can be obtained.

RGB lasers are being exploited as an alternative to arc lamps sources (beamers). Although arc lamps have been used for a long period as a source of beams particularly because they are much cheaper, they suffer from setbacks such as limited lifetime, high wall-plug efficiency is impossible, poor image quality as a result of poor spatial coherence and the fact that available color space is not wide enough. For this reasons, the former is becoming more popular RGB sources are much more popular.

Beams from these sources are known to be coherent in both wavelengths, both in time and space allowing for inferences. If the change in phase properties is able to take place at the same time over a long distance and at the same period of time, then such waves will produce a very clear image. It is possible to cancel such waves with a similar with opposite phase.

The narrow optical bandwidth of the three types of beams produced put them close to monochromatic beams, a property that makes them able to produce very sharp and clear images on color mixing. For this reason, their applications are increasing, not forgetting the use in cathode tubes, lamp based beamers, color printers and many types of projectors.

These beam sources however are associated with low level power emission. With cinema projectors demanding 10 W for each color or more, these projectors have to be designed to meet this power demand level for them to be usable. Their level of power sufficiency, maturity and cost effectiveness are the major setbacks when it comes to their application.

In situations where optical modulators is not practical as a result of low-power miniature devices or for any other reason, the RGB sources are fitted with power-modulators for better signals. Using laser diodes in particular helps achieve modulation bandwidth of tens to hundreds of megahertz or even higher resolutions.

There are many methods of constructing RGB lasers. Three lasers with each emitting a particular light of a wanted color is for instance an approach that has been used for long. These visible light beams are however limited in performance as compared to those that are infrared based.

The use of infrared solid-state lasers involves application of a single laser that emits a beam of near infrared (invisible) nature. Such a beam then undergoes through several stages of nonlinear frequency conversion the end of which a three colored beam is produced. The other methods that have also been used to obtain these colors are the combination of parametric oscillators, the use of frequency doublers and the use of frequency mixers.

Technological advancement is however set to completely address the challenges in with an RGB laser. Just like other forms of lasers, they are set to be used in all other areas where there are need for lasers like in hospital machines, cutting technology and in entertainment industry among others.