ASU researchers show off first white laser

Lasers have been around since the 60s and are used in many different applications today. Lasers come in several colors including red and green among others, but one color has eluded scientists until now. A group of researchers at Arizona State University have created the world's first white laser. The team has shown that semiconductor lasers are capable of emitting the full visible color spectrum required to produce a white light laser.

To perform this feat, the researchers have created a nanosheet, which is a thin layer of semiconductor about one-fifth the thickness of a human hair in size that is one-thousandth the thickness of a human hair. The film has three parallel segments that support laser action in one of the three elementary colors of red, green, and blue.

Using that semiconductor sheet and the segments for each elementary color, the laser created is tunable in color and can produce a beam in red, green, blue, and any color in between. Researchers say when the total field is collected, white light is produced.

By creating white light with a laser, the team is one-step closer to making lasers a mainstream light source and a potential replacement for LEDs. Lasers are brighter, more energy efficient, and could provide more accurate and vivid colors for computer screens and TVs. The white laser might also be used in light-based wireless communications known as Li-Fi, an alternative to WiFi common today. The next step for the researchers is to create a white laser that can be driven by a battery.