Nano-lasers to light future homes

Melbourne, June 30 : Scientists have invented a way to 'print' lasers that could possibly be used to create wafer-thin televisions and lighting panels.

Conventional lasers are expensive and are not used in printed technologies.

But researchers from CSIRO, the University of Melbourne and the University of Padua in Italy, have overcome the hurdle by creating affordable tiny, printable lasers using a technology based on ''quantum dots'' - nano-sized crystals of semiconducting material.

The researchers suspend these nanocrystals in liquid to create ''inks'' which they then printed onto a glass-like material with nanoscale grooves in it.

When light is shone onto the material, it is bounced around inside the grooves and builds up in intensity, exciting the electrons in the quantum dots to a higher energy level and causing them to give off their own light.

The colour of the light depends on the size of the nanoparticle.

"If we printed our lasers on a sheet of paper then every single point on that paper would be its own individual laser. It''s a flat panel laser," ABC Science quoted Dr Jacek Jasieniak, a nano-technologist with CSIRO, as saying.

The technology could be used to create flat coloured lighting panels, or television displays, where each pixel is an individual laser.

"What we want is to eventually be able to replace white light sources in conventional televisions with individual laser pixels that emit light," he added.

The ''Holy Grail'' for this work, says Jasieniak, is to create lasers that are driven by electricity rather than light.

"The whole idea of taking quantum dots and developing appropriate inks to print different devices is a big thing for the future. We could completely revolutionise printing processes to develop next-generation technologies," he added.