@article { ISI:000286807100060,
	title = {Bonding, antibonding and tunable optical forces in asymmetric membranes},
	journal = {Optics Express},
	volume = {19},
	number = {3},
	year = {2011},
	month = {JAN 31},
	pages = {2225-2241},
	publisher = {OPTICAL SOC AMER},
	type = {Article},
	address = {2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA},
	abstract = {We demonstrate that tunable attractive (bonding) and repulsive (anti-bonding) forces can arise in highly asymmetric structures coupled to external radiation, a consequence of the bonding/anti-bonding level repulsion of guided-wave resonances that was first predicted in symmetric systems. Our focus is a geometry consisting of a photonic-crystal (holey) membrane suspended above an unpatterned layered substrate, supporting planar waveguide modes that can couple via the periodic modulation of the holey membrane. Asymmetric geometries have a clear advantage in ease of fabrication and experimental characterization compared to symmetric double-membrane structures. We show that the asymmetry can also lead to unusual behavior in the force magnitudes of a bonding/antibonding pair as the membrane separation changes, including nonmonotonic dependences on the separation. We propose a computational method that obtains the entire force spectrum via a single time-domain simulation, by Fourier-transforming the response to a short pulse and thereby obtaining the frequency-dependent stress tensor. We point out that by operating with two, instead of a single frequency, these evanescent forces can be exploited to tune the spring constant of the membrane without changing its equilibrium separation. (C) 2011 Optical Society of America},
	issn = {1094-4087},
	doi = {10.1364/OE.19.002225},
	author = {Alejandro W. Rodriguez and McCauley, Alexander P. and Hui, Pui-Chuen and Woolf, David and Iwase, Eiji and Federico Capasso and Loncar, Marko and Steven G. Johnson}
}
