Microdisks are special tiny resonators that trap light inside themselves and enhance the incoming light for specific applications. They rely on the whispering-gallery optical effect, similar to the sound-based effect of the same name that’s demonstrated at many children’s museums. Microdisks have great potential for assessing the state of individual cells at the point of care, but existing devices are limited by the wavelength of light they can work with, as well as their stability and other factors that affect their accuracy.
Scientists at the Harbin Institute of Technology in China have now reported on a way of injecting light into such microdisks to allow them to work with a much wider set of wavelengths of light and to do accurately and repeatedly. The new capability should reduce the cost of developing and manufacturing microdisks, as well as make them practical for clinical applications.
The team built a so-called “end-fire injection configuration” that channels light into a microdisk resonator. Using the new approach, the team was able to detect the existence of nanoparticles in a studied sample, as well as spot temperature changes taking place.
The more distant goal is to be able to detect minute changes in the nature of cells that are analyzed using a microdisk, potentially allowing physicians to inspect tissue samples quickly and easily for signs of cancer.
Details of the technology can be found in journal Optica: End-fire injection of light into high-Q silicon microdisks…
Via: The Optical Society…