Micro/nano-fiber measurement

Micro/nano-scale fibers are now one of the most important materials for optical waveguides, optical sensors, material reinforcements, and filters/catalysts. Their diameters and diameter distributions have been measured by scanning electron microscopy (SEM) in general. Still, there are some troublesome aspects, such as vacuum conditions and the non-conductivity of the fibers. So, we will develop the optical measurement method, which utilizes interference of Mie scattered light with two incident beams. This method aims to measure diameters below 500 nm, which has been difficult to measure and realize in-process measurement.

M. Michihata, et al, “Diameter measurement of nano/micro-optical fiber based on effective refractive index including uncertainty analysis with Monte Carlo simulation,” Precision Engineering (in press)

doi: https://doi.org/10.1016/j.precisioneng.2025.09.009

Y. Liu, S. Kadoya, M. Michihata, S. Takahashi, “Propagation constant-based diameter measurement technique for sub-micrometer scale optical fiber”, Optics Letters,  vol. 49, issue 10 (2024) pp. 2649-2652.

doi: https://doi.org/10.1364/OL.521545

M. Michihata, et al, Measurement of diameter of sub-micrometer fiber based on analysis of scattered light intensity distribution under standing wave illumination, CIRP Annals -Manufacturing Technology, vol. 71, issue 1 (2022) pp. 421-424.
​doi: https://doi.org/10.1016/j.cirp.2022.03.008

M. Michihata, et al, In-process diameter measurement technique for micro-optical fiber with standing wave illumination, Nanomanufacturing and Metrology, vol. 4, issue 1 (2021) pp. 28-36.   

​doi: https://doi.org/10.1007/s41871-020-00081-4

材料強化やフィルター/触媒に加え、光導波路、光学センサなどマイクロ/ナノスケールのファイバーは現在非常に重要な材料の一つです。その直径や直径分布は、走査型電子顕微鏡（SEM）での測定が行われていますが、真空状態にしたり、導電性を持たない場合の対応など面倒な部分が存在します。この研究では、光を用いてその直径を測定します。一般に光学計測の場合、Mie散乱理論に基づいて測定されますが、この研究では、2本の光を入射しMie散乱の干渉場を測定することで、これまで測定が難しかった500 nm以下の直径計測や、インプロセス高速計測などの実現を目指しています。