Liquid nanoscale laser technology could revolutionise medical diagnostics

Medical diagnostics could enter a 'lab-on-a-chip' era, with the development of the first liquid nanoscale laser technology, IANS reported.

The laser, which is tunable in real time, allows quick and easy production of different colours, a useful and unique feature.

According to scientists, the laser technology could lead to practical applications, such as a new form of a "lab-on-a-chip" for medical diagnostics.

The concept can be best understood by imagining a laser pointer whose colour could be changed by simply changing the liquid inside it, rather than having to use a different laser pointer for every desired colour.

Besides changing colour in real time, the liquid nanolaser had additional advantages over other nanolasers in that it was easy to make, inexpensive to produce and operated at room temperature.

First demonstrated in 2009, nanoscopic lasers are only found in research labs today and are of great interest for advances in technology and military applications.

According to Teri W Odom from the Northwestern University, who led the research, the study allowed the researchers to think about new laser designs and what could be possible if they could actually be made.

The researchers, he said, believed this work represented a conceptual and practical engineering advance for on-demand, reversible control of light from nanoscopic sources.

The liquid nanolaser in the study was not a laser pointer but a laser device on a chip, according to Odom. The colour of the laser could be changed in real time when the liquid dye in the microfluidic channel above the laser's cavity was changed.

The laser's cavity comprises an array of reflective gold nanoparticles, where the light was concentrated around each nanoparticle and then amplified.

Conventional laser cavities require mirrors to bounce the light back and forth.

Notably, as the laser colour was tuned, the nanoparticle cavity stayed fixed and did not change, only the liquid gain around the nanoparticles changed.