Optical nanofibre integrated into an optical tweezers for particle manipulation, in situ fibre probing, and optical binding studies

TL;DR

This paper presents an integrated optical nanofibre and tweezers platform enabling precise particle manipulation, in situ fibre and particle size measurement, and studies of optical binding and light-particle interactions.

Contribution

It introduces a novel combined system for particle control and measurement, enhancing capabilities for optical manipulation and in situ analysis.

Findings

Transmission dips depend on particle and fibre diameter

Reversible transmission modulations enable size measurement

Platform facilitates optical binding studies

Abstract

Precise control of particle positioning is desirable in many optical propulsion and sorting applications. Here, we develop an integrated platform for particle manipulation consisting of a combined optical nanofibre and optical tweezers system. Individual silica microspheres were introduced to the nanofibre at arbitrary points using the optical tweezers, thereby producing pronounced dips in the fibre transmission. We show that such consistent and reversible transmission modulations depend on both particle and fibre diameter, and can be used as a reference point for in situ nanofibre or particle size measurement. Thence, we combine scanning electron microscope (SEM) size measurements with nanofibre transmission data to provide calibration for particle-based fibre assessment. This integrated optical platform provides a method for selective evanescent field manipulation of micron-sized particles and facilitates studies of optical binding and light-particle interaction dynamics.