2022/01/18
Keio University
National Institute of Advanced Industrial Science and Technology (AIST)
A research group, which included Kana Sumihara (at the time a student at the Graduate School of Science and Technology, Keio University; now graduated), former Senior Assistant Professor Masato Okano of the Department of Physics, Faculty of Science and Technology at Keio University (currently Associate Professor at the National Defense Academy of Japan), Professor Shinichi Watanabe, principal investigator Akira Okubo of the Optical Frequency Measurement Research Group, Research Institute for Physical Measurement at the National Institute of Advanced Industrial Science and Technology (AIST), and Research Group Leader Hajime Inaba, has developed a technology to simultaneously measure the thickness and refractive index of planar materials with extremely high precision.
For the design of optical elements such as optical lenses, it is essential to accurately determine the refractive index of the constituent materials. It is also important to accurately determine the thickness of the planar material before processing it into an optical lens. The group has now developed a non-contact method using dual-comb spectroscopy, which can directly and accurately measure the phase change of light, to simultaneously measure the thickness and refractive index of a planar silicon material with high precision across multiple wavelengths. This groundbreaking method allows for the measurement of a material's refractive index with ultimate precision while it remains in a planar shape. In the future, applying this method to the accurate measurement of the refractive index of various optical materials is expected to lead to the high-precision design of optical elements.
The results of this research were published in "Optics Express" on January 12, 2022 (local time).
Please see below for the full press release.