[Dan McCann]

In Mid 2010, QD Laser Inc. will commercialize a green laser that uses quantum dot semiconductor technology for use in mobile projectors that can be mounted on mobile phones or laptop PCs.



Developed in collaboration with Prof. Yasuhiko Arakawa of the University of Tokyo’s Institute for Nano Quantum Information Electronics, the laser measures 5.6 mm in diameter and consumes little power since it can operate up to 60°C without the need for cooling.

Devising the focus-free, mobile projector required three different lasers: red, blue and green. Tokyo-based QD Laser reported that until the introduction of this new technology, “a green laser had not existed that combines the features of being compact enough for practical use with low power consumption and mass production at a lower cost.”



Key to the production of the green laser is the application of distributed feedback (DFB) laser technology, which is used in high-reliability optical communications to create a quantum dot semiconductor crystal laser with a wavelength of 1064 nm. (DFB lasers oscillate in a single mode as the active region of the semiconductor laser is structured using diffraction gratings, where only wavelengths in the interval of the diffraction gratings are amplified.)


The photon stream is subsequently filtered through a nonlinear crystal via the process of second-harmonic generation, thereby forming photons with a wavelength of 532 nm, half the original wavelength. QD laser noted that the conversion of the 1064 nm quantum dot laser from electricity to light is efficient and results in significantly reduced power consumption.