We develop single fiber based optical tweezers employing photophoretic forces to trap absorbing particles exploiting the rotational motion displayed by the particles to be stably trapped radially. This implies that optical beams with a large off-axis intensity would prove to be more efficacious in trapping. Thus, we generate a pure Gaussian as well as a superposition of Gaussian and Hermite-Gaussian beam modes from a single optical fiber which is dual mode at our operating wavelength, and show that the latter is more efficacious in trapping by about 1.8 times than the former. Finally, we show that multimode fiber traps - which have even larger off-axis intensity distribution - are the most effective in trapping and manipulating absorbing particles.

Date Published: 9 September 2019
PDF: 9 pages
Proc. SPIE 11083, Optical Trapping and Optical Micromanipulation XVI, 110833A (9 September 2019); doi: 10.1117/12.2529859

Published in SPIE Proceedings Vol. 11083:
Optical Trapping and Optical Micromanipulation XVI
Kishan Dholakia; Gabriel C. Spalding, Editor(s)