Encircling tumors with a phalanx of miniature lasers could offer a new way to battle cancer, a team of Australian researchers is proposing.
Technically, the proposed device isn't really a laser at all, but a spaser, with surface plasmons rather than light undergoing amplification.
Plasmons are oscillations in electron density created in the surface of a small metal object when photons strike it. It's possible to design a device so that the plasmons feed back on themselves, amplifying in much the same way photons bouncing around a laser cavity stimulate the emission of other photons, creating laser light.
"The spaser is basically the same as a laser," says Chanaka Rupasinghe, a postgraduate student in electrical and computer engineering at Monash University near Melbourne, Australia. He and his professor, Malin Premaratne, presented their idea in a paper at the recent IEEE Photonics Conference, in Los Angeles.
Spasers have been built of gold nanoparticles surrounded by a silica shell and from cadmium sulfide nanowires on a silver substrate. Earlier this year, Rupasinghe and Premaratne proposed a different design, using graphene and carbon nanotubes.