Nature Photonics: Ultraviolet Convenience

DOI: 10.1038/nphoton.2008.135

Scientists have developed electrically powered semiconductor laser diodes that operate at a shorter wavelength than any others used today. The lasers, described in the September issue of Nature Photonics, could be used for the next generation of optical storage systems following today's Blu-ray disks, and will have applications in biomedicine, materials processing and microchip manufacture.

Electrically powered semiconductor laser diodes are a highly convenient source of laser light, and shorter wavelengths of operation have become available, with the potential to enable larger-capacity optical data storage. Now, Harumasa Yoshida and colleagues describe an electrically powered semiconductor laser diode that operates effectively at a UV wavelength - the shortest so far at 342 nanometres, and 63 nanometres shorter than the laser wavelength used in Blu-ray disks.

Importantly, the laser contains no indium - a component usually added to improve the efficiency of a UV laser diode, but which limits device operation to longer wavelengths. They prove that it is possible to create a practical and efficient indium-free UV laser diode that operates at room temperature and emits powers in the milliwatt range when driven by a pulsed electrical current.