Better lasers

The University of Cambridge has been awarded £2.4 million under the UK Research Council’s Basic Technology Research Initiative for the development of microscopic lasers.

The multidisciplinary collaborative research project will tap into the expertise of the University’s Department of Engineering, the Department of Physics and the Department of Chemistry.

The new lasers, based on liquid crystals and light emitting polymers, will combine the best features of dye, gas and diode lasers.

Dye lasers can be tuned to emit different wavelengths, but they are big. Gas lasers are powerful and stable, but they cannot be tuned and are also rather large. Diode lasers, such as those used in CD and DVD players, are small but cannot be tuned.

The new lasers will be extremely small in size - less than the width of a human hair. They will be stable and emit very pure light, because they will not hop from one mode of emissions to another. And it will be possible to tune them to any wavelength from ultraviolet to infrared simply by sending an electrical signal to them. On top of this, it should be possible to manufacture them at extremely low cost.

The lasers will find use in medical science given their small size, tuneability and low cost. They may be incorporated into fibre optics and this will open up applications in dermatology, cancer and diabetes detection as well as the possibility of using them in the so-called 'lab on a chip' technology.

The lasers are small enough that they can also act as individual picture elements of a display. They can be switched fast enough to provide bright pure light of any colour. No filters or backlighting will be required so a display based on them will be brighter, sharper and consume less power.