Modelling the response of whispering-gallery-mode optical resonators for biosensing applications

We present a theoretical analysis of the response of whispering gallery modes for biosensing applications, studied numerically in microcylinders and semi-analytically in microspheres. The effect of single and multiple particles is calculated, simulating biological analytes of different sizes and polarizabilities attached to the microresonator surface. Besides whispering-gallery-mode frequency shifts, we find that also broadenings and splittings (from lifted rotational symmetry) appear due to particles attachment and/or the vicinity to a planar coupler. For a single analyte, both particle size and refractive index can be determined from the broadening and shift, opening the perspective to a new biosensing modality.

[1]  Tao Ling,et al.  A unique resonance mode observed in a prism-coupled micro-tube resonator sensor with superior index sensitivity. , 2007, Optics express.

[2]  Dieter Braun,et al.  Protein detection by optical shift of a resonant microcavity , 2002 .

[3]  Rajan P Kulkarni,et al.  Label-Free, Single-Molecule Detection with Optical Microcavities , 2007, Science.

[4]  D. Braun,et al.  Multiplexed DNA quantification by spectroscopic shift of two microsphere cavities. , 2003, Biophysical journal.

[5]  Wolfgang Werner Langbein,et al.  Optical resonances in microcylinders: response to perturbations for biosensing , 2008 .

[6]  Young,et al.  Time-independent perturbation for leaking electromagnetic modes in open systems with application to resonances in microdroplets. , 1990, Physical review. A, Atomic, molecular, and optical physics.

[7]  C.-M. Yuan,et al.  Efficient light scattering modeling for alignment, metrology, and resist exposure in photolithography , 1992 .

[8]  Julie Lutti,et al.  A monolithic optical sensor based on whispering-gallery modes in polystyrene microspheres , 2008 .

[9]  R. Windeler,et al.  Optical liquid ring resonator sensor. , 2007, Optics express.

[10]  Andreas Erdmann,et al.  Rigorous simulation of alignment for microlithography , 2003 .

[11]  Julie Lutti,et al.  High Q optical resonances of polystyrene microspheres in water controlled by optical tweezers , 2007 .

[12]  Degeneracy breaking of optical resonance modes in rolled-up spiral microtubes , 2007 .