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 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.
The LD's luminosity as a red light source exceeds 220 lumens due to lasing at short wavelength. Its electrical conversion efficiency is 38% at 1.8 W at 25 degrees Celsius, helping to reduce power consumption
Besides emitting 1.8 W at continuous wave operation within an operating range of 0 to +45 degrees Celsius, the laser diode is able to emits 1.3 W at continuous wave operation above 55 degrees Celsius.