Chalmers blue laser project could revolutionize industries
New Chalmers research tries to realize novel laser structure to minimize energy use and improve health care. Result: a high quality laser with properties to revolutionize todays sectors of applications.
In the vertical-cavity laser configuration, see Figure, light bounces back and forth between an upper and a lower mirror and is amplified in the very thin (~10 nm thick) amplification region. The amplification is achieved by pumping this region with an electrical current. Since the amplification region is very thin, high reflectivity mirrors (>99%) are necessary to achieve lasing. These mirrors consist of alternating quarter-wavelength-thick layers with high and low refractive index material. These two materials must have a large refractive index difference, and at the same time be lattice matched to the materials used in the light amplification region. This is one of the two main challenges in realizing blue vertical-cavity lasers. The second main challenge is to achieve an efficient current pumping since the materials (III-nitrides) have poor electrical conductivity.
Illustration: schematic view of an electrically pumped blue vertical-cavity laser (not to scale).
This novel blue laser could provide enormous benefits to several industries due to its low power consumption and low cost. For example, the biomedicine industry can use blue laser light to distinguish between normal and cancer cells through fluorescence studies, without sampling human body tissue. This would drastically lower costs and rationalize the cancer diagnostics process. Another example is the oral health care industry where blue laser has been demonstrated to be able to spot tooth decay. New applications are continuously arising. Besides improved health care and higher resolution laser printers, these blue lasers will have ultra-low power consumption and thereby play an important role in today’s battle for a sustainable future.
Uppdaterad: 31 oktober 2011
Ansvarig för sidan: Christophe Elehn