Liquid crystal elastomers used to create "rubber lasers"
We generally picture lasers as being encased within hard housings, much like most other electronics. Thanks to research being conducted at Kent State University and Japan's Kyoto Institute of Technology, however, we could soon see sensors or other devices that incorporate stretchable laser-emitting rubber.
In traditional lasers, a beam of laser light is reflected back and forth between mirrored surfaces within a small cavity. This process essentially tunes the emitted laser beam to a given frequency.
Previously, some of the key scientists had demonstrated that liquid crystals within a liquid crystal elastomer (LCE) material could be used to "bounce" laser light, although it wasn't possible to control the tuning of the beam. Now, using a new type of cholesteric LCE, they've overcome that limitation.
In lab tests, a cavity within the LCE was successfully used to form a tunable beam of laser light, while the material was being stretched. Additionally, as the LCE deforms due to mechanical strain or other factors such as changes in temperature, the frequency of the laser is altered. According to one of the study leaders, Kent State's Dr. Peter Palffy-Muhoray, this quality could make the material ideal for certain sensing applications.
"In principle, it could be put into a shoe, to measure shear stress on a diabetic foot, and it could be interrogated by an optic fiber; a pulse of light could be sent in the fiber, and the color of the returning light from the laser emission would carry information about the strain," he says. "Similarly, remote equipment could be monitored – by measuring stress, strain, temperature and presence of chemicals – by optic fibers using light."
A paper on the research was published this month in the journal Nature.
Source: Kent State University