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FEM/FDTD Modeling

Model 1

FDTD Modeling
We use finite difference time domain, specifically Lumerical, to model many of the properties of the optical fields in our waveguides and resonators.  For example, we model the location, profile and intensity of the field.  Depending on the scale needed, simulations are in 2D or 3D. 
FEM Modeling
We perform finite element method (FEM) modeling, specifically COMSOL Multiphysics, to model the complex, inter-related, time-dependent behaviors of our structures.  COMSOL allows different physical phenomena to be linked together – for example, mass transport of a biological species to the surface of a sensor and it binding kinetics at the surface.  The most frequent models incorporate E&M, heat and mass transfer, mechanical behavior and kinetics.


Recent papers in this area:
M. Harrison, A. M. Armani, "Portable polarimetric fiber stress sensor system for visco-elastic and biomimetic material analysis", Applied Physics Letters 106 (20), 191105 (2015).
X. Zhou, L. Zhang, A. M. Armani, J. Liu, X. Duan, D. Zhang, H. Zhang, W. Pang, "An integrated photonic gas sensor enhanced by optimized Fano effects in coupled microring resonators with an athermal waveguide", Journal of Lightwave Technology 33 22, 4521-4530 (2015).
M. V. Chistiakova, A. M. Armani, "Photoelastic ultrasound detection using ultra-high-Q silica optical resonators", Optics Express 22 (23), 28169-28179 (2014).
M. I. Cheema, C. Shi, A. M. Armani, A. G. Kirk, "Optimizing the signal to noise ratio of microcavity sensors", IEEE Photonics Technology Letters 26 (20), 2023-2026 (2014).
S. Soltani, A. M. Armani, "Optothermal transport behavior in whispering gallery mode optical cavities", Applied Physics Letters 105 (5), 051111 (2014).
M. Harrison, A. M. Armani, “Spatiotemporal fluorescent detection measurements using embedded waveguide sensors”, IEEE Journal of Selected Topics in Quantum Electronics 20 (2), (2014)
X. Zhou, L. Zhang, A. M. Armani, R. G. Beausoleil, A. E. Willner, W. Pang, "Power enhancement and phase regimes in embedded microring resonators in analogy with electromagnetically induced transparency", Optics Express 21 (17), 20179-20186 (2013).
S. Soltani,  A. M. Armani, “Optimal design of suspended silica on-chip splitter”, Optics Express 21 (6), 7748-7757 (2013).
C. R. Murthy,  A. M. Armani, “Mass transport effects in suspended waveguide biosensors integrated in microfluidic channels”, Sensors 12 (11), 14327-14343 (2012).
X. Zhang, M. Harrison, A. Harker, A. M. Armani, “Serpentine low loss trapezoidal silica waveguides on silicon”, Optics Express 20 (20), 22298-22307 (2012).
A. J. Maker, B. A. Rose, A. M. Armani, “Tailoring the behavior of optical microcavities with high refractive index sol-gel coatings”, Optics Letters 37 (14), 2844-2846 (2012).
C. Shi, H. -S. Choi, A. M. Armani, “Optical microcavities with a thiol-functionalized gold nanoparticle polymer thin film coating”, Applied Physics Letters, 100 (1), 013305 (2012).
A. Maker, A. M. Armani, “Low loss silica on silicon waveguide”, Optics Letters, 36 (19), 3729-3731 (2011).
X. Zhang, A. M. Armani, “Suspended bridge-like silica 2x2 beam splitter on silicon”, Optics Letters, 36 (15), 3012-3014 (2011).
H.-S. Choi, A. M. Armani, “Thermal non-linear effects in hybrid optical microresonators”, Applied Physics Letters 97 (22), 223306 (2010).
X. Zhang, H.-S. Choi, A. M. Armani, “Ultimate quality factor of silica microtoroid resonant cavities,” Applied Physics Letters 96 (15), 153304 (2010).
H.-S. Choi, X. Zhang, A. M. Armani, “Hybrid silica-polymer ultra-high-Q microresonators,” Optics Letters 35 (4), 459 (2010).