Mitsubishi Electric has developed a 638-nanometer (nm) wavelength red laser diode (LD) offering output power of 1.8 W at continuous-wave operation, the world’s highest level among 638-nm LDs in this package size used as light sources for projectors. Light sources for color projectors, conventionally lamps, are being replaced with solid-state light sources offering higher energy efficiency, higher color reproduction and longer life. LDs deliver high output power while consuming low power because of their high power-conversion efficiency. Previously, the output power of red LDs with wavelengths shorter than 640 nm was not sufficient for high-brightness projector applications at high temperatures.
As a first step to overcome this limitation, Mitsubishi Electric applied specialized window-mirror structures and epitaxial growth technology to develop an LD capable of 0.5 W power output at continuous-wave operation, which is packaged in a 638-nanometer wavelength red laser diode 5.6-mm-diameter transistor-outline can (TO-can). Thereafter, it applied a new LD structure in a 9.0-mm TO-can package to achieve industry-leading output power of 1.8 W at a 638-nm lasing wavelength, which meets demands for bright projector systems. A commercial launch is targeted for the fiscal year ending in March 2016 at which time laser light sources for projectors are expected to take off.
