OSRAM Opto Semiconductors today announced a major breakthrough in the laboratory with its direct emitting green indium-gallium-nitride laser. It achieves an optical output of 50 mW and emits light in true green with a wavelength of 515 nm. Compared with semiconductor lasers based on current technology that operate with frequency doubling, direct emitting green lasers are more compact, offer greater temperature stability, are easier to control and have higher modulation capability, according to the company.

OSRAM has overcome the previous limits of the InGaN material system. The company succeeded in manufacturing the first direct emitting green laser diode from the InGaN (indium-gallium-nitride) material system at the pre-development stage. The diode emits a “true green”, which is defined by the spectral range of 515 to 535 nm. And in the medium term, direct emitting green lasers already could replace frequency-doubled lasers for numerous applications. They are easier to control, and also offer greater temperature stability, a smaller form factor and higher modulation capability at several 100 MHz, according to the company.

Preliminary performance data are impressive. In pulsed mode at room temperature the laboratory prototype has achieved an optical output of 50 mW; the threshold current density is around 9 kA/cm². Green lasers are used in numerous medical and industrial applications, but also as light sources in mobile mini-projectors. A direct emitting green laser can help make these projectors even smaller with even better performance.

Picture: OSRAM