Nearfield optical micromanipulation with cavity enhanced evanescent waves

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Near-field optical micromanipulation with cavity enhanced evanescent waves Peter J. Reece, a Veneranda Garcés-Chávez,

Near-field optical micromanipulation with cavity enhanced evanescent waves Peter J. Reece, a Veneranda Garcés-Chávez, and Kishan Dholakia School of Physics and Astronomy, University of St Andrews, Saint Andrews, Fife KY 16 9 SS, Scotland, United Kingdom Prepared by David Keng Nov. 3, 2006

Important things in this paper • Near-field optical micromanipulation with cavity enhanced evanescent waves

Important things in this paper • Near-field optical micromanipulation with cavity enhanced evanescent waves • Near-field optical micromanipulation • cavity enhanced evanescent waves

Near-field optical micromanipulation • Optical guiding and/or trapping particle with evanescent waves

Near-field optical micromanipulation • Optical guiding and/or trapping particle with evanescent waves

Near-field optical micromanipulation • In this paper… 1064 nm CW laser (4 W, IPG

Near-field optical micromanipulation • In this paper… 1064 nm CW laser (4 W, IPG Yb doped fiber laser) Velocity of 5 m polymer colloids at a BK 7 glass-water interface… ~4 um/s 1. 8 W focused to a 200 um spot (without enhancement layer!) With enhancement layer… 22± 2. 7 um/s!! 1. 8 W / (2 x 10 -4 m)2 0. 005 W / (4 x 10 -6 m)2 = 4. 5 x 107 W/m 2 = 3. 1 x 108 W/m 2 Theirs… Inside MP 3 L tapered fiber

Conclusion for Near-field optical micromanipulation • To guide a particle… particle trapped within E.

Conclusion for Near-field optical micromanipulation • To guide a particle… particle trapped within E. W. above surface • To trap a particle… two counter propagating waves • Larger the particle size… easier to trap smaller the Brownian motion (high drag) higher polarizability (stronger trapping force) • Should be able to perform on the tapered fiber…

Enhancement • “dielectric resonator” Looks like this… SF 11 1. 754 Si. O 2

Enhancement • “dielectric resonator” Looks like this… SF 11 1. 754 Si. O 2 Zr. O 2 H 2 O 1000 nm 127 nm 1. 45 1. 97 1. 33

Enhancement • • Light is launched into the 127 nm layer 32 times of

Enhancement • • Light is launched into the 127 nm layer 32 times of the incident intensity in the layer 25 times at the surface 5~10 times measured… v = 2~4 vs. 22