Ultrahigh-Precision Diameter Control of Nanofiber Using Direct Mode Cutoff Feedback

Precise diameter control is critical for many optical micro/nanofiber (MNF) applications. We demonstrate real-time MNF diameter control with improved accuracy and precision. Different from earlier works, a white light source is applied to monitor the transmittance during fiber pulling process. Terminated directly by the transmission intensity drops that indicate the cutoff of TE01 mode at particular wavelengths, we achieve diameter control accuracy and precision as high as 2nm and 3nm, respectively. The diameter control range from 360 nm to 680 nm that is demonstrated in our experiment can be extended to several tens of micron by exciting other high order modes.