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We present a nonlinear modulation scheme based on coupling between optically excited surface plasmons in a thin gold film and the heating of the film by a pulsed direct current, and also for the reverse process. The reflected surface-plasmon excitation beam is shown to undergo a spatial deformation as a function of a pulsed current through the foil. Similarly, the current through the thin film is modulated by the action of periodic excitation of surface plasmons using infrared photons.

Chemical sensing using optical diffraction from an array of microcantilevers is demonstrated. Properly fashioned arrays of micromachined silicon-nitride cantilevers containing embedded deformable diffraction gratings are functionalized with chemically selective coatings. Adsorption of specific molecules on the cantilever leads to bending, which changes the diffraction pattern of a laser beam reflecting off the array. Quantitative chemical information can be obtained by monitoring the displacement of diffraction peaks as a function of analyte exposure.