Carrots are good for the eye, Now scientiests at the indian institute of technology – madras have proved that carrots can also help humans see objects that are otherwise invisible to the naked eye.
A Team from indian institute of technology madras found that carrots can be an effective medium to produce a biocompatible laser with appications in photonics, the branch of technology dealing with photons (units of light).
It all started at a Friday evening experiment in one of the physics laboratories at IIT – M when research scolar Venkata Siva Gummaluri was shooting blue laser light onto a processed carrot. What came out – scattered laser light in the green – to – red wavelengths surprised him. C Vijayan, a physics faculty member soon joined in. they realised that the effect was something Nobel winning physicist from chennai C V Raman hand observed in 1922 (fir which he won the Nobel in 1930); only that this time it happened with a piece of vegetable.
Vijayan said the successful experiment is a first and a small step towards developing photonic technologies using green materials. “At present nobody uses a biological material to produce laser. This doesn’t replace existing technology, but here is the possibility of generating biocompatible lasers using carrots,” said Vijayan.
For the experiment, the researchers came up with a simple ‘recipe’. A piece of carrot is washed and cooked in ethanol (alcohol). A cintinuous wave of blue laser light is pumped through the carrot, which upon absorption, scattered laser light of green to red wavelength. Since, the research involved used edible materials and did not require any other optics, scientists call it a ‘kitchen laser’.
Assistant Professor Sivarama Krishnan explained the carrot laser. Here, we took advantage of Raman effect, Carrot has beta carotene (that gives the vegetable the orange color) the right dye with efficient Raman interaction, along with an appropriately dense network of fiveres that can scatter light. The scattered light formed a loop insid the carrot, reflecting and amplifying the light (conventional laser gadgets use mirrors to do this). “It’s natural and a complete biocompatible system.” Said Krishnan.
The scientists said their technology can be used in photonics required in bio-imaging like microscopy used in research labs and in diagnostic equipment. The Carrot laser can also be used in temperature sensing, like thermometer, as the light emitted shows a linear response to temperature.
“When more and more technologies are turning green, photonics is lagging behind because of its reliance on very special materials, the laser diode used now is made of a complicated and a bio-unfriendly process. Our work shows that we can use green materials to develop photonic technologies,” said Vijayan.
Krishnan also said the properties of this carrot laser is different from the conventional ones, as the laser is emission here is not coherent like those in the current laser technologies. “Here it is an random laser and it works to our advantage as it has certain applications like in microscopy, where people do not want a coherent source of light, but want it to be bright,” he said.