Numerical investigation and optimisation of hollow-core photonic crystal fibre for optical trapping of fluorescent microparticles

This Letter proposes and demonstrates the optical trapping of fluorescence sample in a transversely-probed microstructured hollow-core photonic crystal fibres (HC-PCFs). The transmission intensity distribution at the central core of liquid-filled HC-PCFs with different central wavelengths is monitored for both the transverse electric and transverse magnetic modes, with illumination in the Γ-M direction. Forces acting on a sphere located inside the central core along the transverse direction of these liquid-filled fibres are calculated and compared using finite-difference time-domain method and Maxwell stress tensor-based method. The proposed concept is illustrated by trapping fluorescent microsphere particles to the core of liquid-filled HC-PCF and the presence of sample particles is confirmed by fluorescence signatures. The obtained results indicate that the proposed concepts have tangible potential for developing novel optical manipulation and trapping inside HC-PCFs and are expected to find potential biomedical diagnostic applications.