Scientists have developed the first liquid nanoscale laser that is tunable in real time, meaning it can quickly produce a variety of colors.
This new laser technology could lead to the creation of a new "lab on a chip" for improved medical diagnoses, Northwestern University reported. The innovation is also relatively inexpensive to produce and can operate at room temperature.
The new liquid nanoslaser is not a laser pointer, but rather a laser device on a chip. The laser's color can be changed in real time when the liquid dye held in its microfluidic channel is changed. The device also contains a cavity composed of an array of gold nanoparticles; in the cavity, light is concentrated around each nanoparticle and amplified.
The advantages of tiny lasers are that they: be used on a chip and for optical data storage; can operate reliably at one wavelength; and most likely will operate much more quickly than conventional lasers because they are made from metals.
In the past, plasmon nanolasers had only been achieve using solid material, which cannot be easily modified. This new research has pioneered a way to integrate liquid gain materials with gold nanoparticle arrays to create a nanoscale plasmon laser that can be tuned in real time.
Liquid gain materials come with two exciting benefits: the organic dye molecules can be dissolved in solvents with varied refractive indices, allowing the dielectric environment around the nanoparticle arrays to be easily tuned; and the fluid can be manipulated within the microfluidic channel, also making tuning extremely easy.
"Our study allows us to think about new laser designs and what could be possible if they could actually be made," said study leader Teri W. Odom. "My lab likes to go after new materials, new structures and new ways of putting them together to achieve things not yet imagined. We believe this work represents a conceptual and practical engineering advance for on-demand, reversible control of light from nanoscopic sources."
The findings were published in a recent edition of the journal Nature Communications.
