TY  - JOUR
TI  - Experimental characterisation of holographic optical traps for microbubbles
UR  - http://dx.doi.org/10.1117/12.2055889
VL  - 9126
PB  - Society of Photo-optical Instrumentation Engineers
A1  - Fury, C
A1  - Harfield, C
A1  - Memoli, G
A1  - Jones, PH
A1  - Stride, E
Y1  - 2014/05/02/
N2  - In this study microscopic gas bubbles (7-12 Îm diameter) suspended in water were optically trapped in a custom-built microfluidic slide using holographically generated Laguerre-Gaussian (â?? doughnutâ??) beam optical tweezers. The optical potential was then characterized as a function of bubble size, trapping laser power and trapping beam diameter (Laguerre-Gaussian beam mode) using the trap spring constant in the plane transverse to the beam propagation direction, obtained from the position fluctuations of the bubble in the trap measured by video microscopy and particle tracking. It was found that microbubbles were held at the equilibrium position of buoyant and optical forces at a distance from the focus of the beam that increased with laser power, and that optical trapping in this configuration was only possible within a specific range of trap and bubble parameters. Furthermore an optimum size of the doughnut beam to microbubble diameter which maximized the transverse spring constant was found. A ray optics model of the optical forces acting on microbubbles in a focused Laguerre-Gaussian beam was used in order to calculate the trap spring constants and equilibrium trapping position as a function of the different parameters, and highlight key physical behaviours. © 2014 SPIE.
AV  - public
JF  - Proceedings of SPIE - The International Society for Optical Engineering
N1  - Copyright 2014 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
SN  - 0277-786X
ID  - discovery1433766
ER  -