"We believe this is the best measurement ever made of temperature -- at room temperature," said Andre Luiten, lead researcher and a physics professor at Adelaide. More precise measurements, Luiten points out, are possible at extremely low temperatures, approaching absolute zero.
To record such minute measurements, the thermometer uses two different colored lights -- one red and one green -- injected into a highly polished crystalline disk. The temperature of the crystal affects the rates at which the two lights travel, and thus scientists are able to ascertain the surrounding temperature by observing the difference in travel time.
"When we heat up the crystal we find that the red light slows down by a tiny amount with respect to the green light," Luiten explained.
The technology is detailed in the newest issue of the journal Physical Review Letters.
Luiten and his colleagues at the University's Institute for Photonics and Advanced Sensing think similar techniques could be perfected to record other ultra-sensitive measurements -- like pressure, humidity, force or levels of a trace element.
"Being able to measure many different aspects of our environment with such a high degree of precision, using instruments small enough to carry around, has the capacity to revolutionise technologies used for a variety of industrial and medical applications where detection of trace amounts has great importance," Professor Luiten said.