A red diode laser is a solid state electronics component that produces an intense beam of visible light with wavelengths of 630 to 700 nanometers (nm) in the red portion of the visible spectrum. What kinds of red lasers exist? What are typical applications of red lasers? Red lasers are used in many applications, including laser. Most lasers appear red because red light is the easiest and cheapest color of laser light to produce. The very first working laser, built in 1960, fired a red beam at 694. 3 nanometers using a synthetic ruby crystal. And the. The laser diode chip is the small black chip at the front; a photodiode at the back is used to control output power. As a leading manufacturer of underground laser alignment tools, Laser Tools Co. All of us, at some point in time, have come across a laser.