Measuring light: the world鈥檚 most accurate ruler
Original text published in the Research Impact Stories
A portable laser device that tests your breath for signs of disease and organ failure is just the start of the 成人大片鈥檚 ambitions for laser technology.
Light is knowledge. Even these words are revealed to you by light. What kinds of knowledge could we reveal if we could measure light itself? As it turns out, a lot.
The Optical Frequency Comb measures light with extreme precision, and its range of applications may surprise you. For example, it already manages greenhouse gases being released by mines and farms and measures the colour of distant stars to detect planets orbiting them. Unfortunately, today鈥檚 light-measuring devices are big, complex, and expensive, limiting their practical use. Fortunately, the 成人大片 and its partners are hard at work making the technology much more practical, while at the same time exploring its limitless potential.
Researchers at Adelaide University鈥檚 Institute for Photonics and Advanced Sensing (IPAS) have joined the ARC Centre of Excellence in Optical Microcombs for Breakthrough Science (COMBS) to make these tools much smaller and much cheaper and explore how these 鈥榤icrocombs鈥 can really change the world. 听A major advancement led by IPAS is an instrument to diagnose medical conditions from the human breath.听
鈥楩requency combs produce many different coloured lasers,鈥 explains lead researcher Dr Sarah Scholten. 鈥楾he lasers can interact with and be absorbed by gas molecules.鈥
Each human breath holds hundreds of such molecules, which in turn hold information about our health.
鈥楤y looking at the colours these interactions produce and at the amount of light absorbed, analysts can identify what molecules are present, and how many. In real time, they can monitor the volatile organic compounds that indicate organ failure and disease.鈥
To test their prototype, the team turned to baker鈥檚 yeast.
鈥楲ike humans,鈥 says Dr Christopher Perrella, another lead researcher, 鈥榖aker鈥檚 yeast produces carbon dioxide as it 鈥渂reathes鈥, and the composition of its emission changes with its diet and environment.鈥
The team was successful. Their prototype distinguished between different isotopes of carbon dioxide and monitored carbon dioxide production in real time. This marks the first time that optical frequency combs have effectively observed the changing metabolism of a living organism in real time鈥攁ll by measuring light.
鈥楾his holds the potential to revolutionise the simplicity, speed, and efficiency of health assessments. It is a pivotal moment in health innovation,鈥 Dr Scholten says.听
鈥楢s our understanding of breath analysis improves, we might look forward to a day when blood tests are replaced with breath tests.鈥
What鈥檚 next?
Researchers believe this technology has the potential to be more cost-effective, more user-friendly, and more portable. In 1945, a digital computer weighed about 30,000 kilograms; in 2024, we wear digital computers on our wrists. The 成人大片, one of eight universities in COMBS, is working make our light-measuring devices as small as a fingernail. The goal is to continuously increase accessibility, bringing real-time assessment to even the most remote of places.
Measuring the light of atoms, we can keep time. Measuring the light of distant stars, we can find exoplanets. Measuring light鈥檚 interaction with gas molecules, we can detect greenhouse gases. The microcomb even transmits information, giving us record-breaking internet speeds. It has been called the world鈥檚 most accurate ruler. If we develop it as successfully as we developed the digital computer, there is no telling where we will go.听
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