Sandia conducted tests into the white light generated by diode lasers and discovered the human eye is as comfortable with it as it is with LEDs.
An important difference between lasers and LEDs is the efficiency of each, with LEDs reducing in efficiency at higher currents while lasers improve.
Sandia researcher Jeff Tsao, who proposed the comparative experiment, said: ‘What we showed is that diode lasers are a worthwhile path to peruse for lighting.’
The tests – reported in LEDs Magazine – took place at University of New Mexico’s Centre for High Technology Materials, where 40 volunteers were seated in front of two near-identical scenes. Each both was illuminated by warm, cool or neutral white LEDs, tungsten-filament incandescent light or a combination of four lasers – blue, red, green, yellow – which combined were tuned to create white light.
Volunteers were asked to chose between alternatives – but were not told which source was being used – 80 times. Jonathan Wierer, involved in planning, calibrating and executing the experiments, said there was a significant preference for the diode-laser-based white light over the warm and cool LED-based white light. There was no statistical preference between the laser-based light and either the neutral LED-based or incandescent white light.
Jonathan Wierer, researcher at Sandia, said: ‘We are going to start exploring the challenges of using lasers for solid-state lighting. We are starting to look at topics such as efficiency, quality and economical benefits.
‘We think this idea has potential. It most likely will not have as much universal use as LED-based solid-state lighting, but probably has some potential in specific lighting applications.’
Sandia’s experiment combined the output of four laser colours – blue, red, green and yellow – to create a white light source. The narrow beam is addressed via a suitable optical system.
The Sandia research was published in the 1 July, Optics Express