Single or Multiple Lasers for Color Presentation?
For multiple color presentations, it’s possible to use either a single laser that produces more than one wavelength, or two or more lasers combined into a single beam using dichroic mirrors. The only commercially available multiple wavelength solution is to use a ‘white light’ mixed-gas argon/krypton ion laser. The advantage is that it’s possible to get a reasonable mix of colors and relative intensities, and the beams are already aligned to each-other. The disadvantages include large power requirements, high cost, and possibly relatively short life. The wavelength balance also changes with age, use, and output power. However, there is really is no viable alternative at present to obtain suitable red, green, and blue wavelengths from a single laser. Solid state RGB lasers are never built as single lasers, but either multiple lasers, or one or more lasers with some other wavelength conversion scheme added on. These are very complex and expensive but will no doubt improve and come down i
