Sumitomo Electric and Sony improve green laser diode

Sumitomo Electric and Sony have succeeded in developing a green laser diode with a light output of 100mW at a wavelength of 530nm. The new laser diode can therefore shine twice as bright as current green lasers.

The two Japanese companies achieved the breakthrough by leveraging new technologies and refining current production methods. The researchers at Sumitomo Electric and Sony use a substrate based on semi-polar gallium nitride for the new ‘true green’ laser diode. This substrate allows a homogeneous distribution of indium in the active layer of the laser diode, increasing efficiency.

The developed green laser diode has an output power of 100mW and emits light with a wavelength of 530nm. Until recently, 60mW was the highest achievable in laboratories, producing light with a wavelength of 521nm. The new laser diode is also much more efficient than the 60mW green laser, which was developed in 2010: the so-called wall-plug efficiency of the newly developed green laser diode is eight percent, while previously an efficiency of up to 1.9 percent was achieved.

The higher light output of the green laser diode is especially important for laser projectors. Currently, green laser light is obtained by using infrared GaN laser diodes whose frequency is doubled using another infrared laser and an optical crystal. The disadvantage of this is that the light output is limited and that such a green laser takes up more space.