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This paper describes a free-space 1 timesP cyclically tunable optical multiplexer based on a stationary tunable blazed grating (TBG). An analytical model is used in deriving a closed- form expression for the transmission of the deformable grating, given an actuation scheme that requires only (P -1) control signals. A 1 times3 demultiplexer is implemented using a six-element TBG, and tuning over a free spectral range of 13.5 nm in C-band is demonstrated. [ABSTRACT FROM PUBLISHER]

We present a micromechanical grating array that acts as a configurable optical filter for low-cost and compact visible and near-infrared spectrometric sensors. We show how the grating array can be used either as a fast scanning monochromator or as a diffractive filter, and that the expected signal-to-noise ratio is approximately equal for the two modes of measurement. The free spectral range of the filter can be matched to a defined spectral measurement region, so that we can optimize the relationship between spectral resolution and electromechanical complexity. We have numerically studied diffraction efficiency and errors in filter shape. Finally, we fabricated a small configurable grating array and present measurement results that demonstrate electrostatic filter modulation. [ABSTRACT FROM PUBLISHER]

We present a micromachined cantilever with an integrated high-bandwidth resonator for direct measurement of tip-sample interaction forces in tapping-mode atomic force microscopy. Force measurements are achieved by a diffraction grating that serves as a differential displacement sensor for the tip motion relative to the cantilever body. Time-resolved tip-sample interaction force measurement is demonstrated on a silicon sample following calibration of the probe structure. By using lock-in detection, the harmonics of periodic tip-sample interaction have been utilized to obtain high-contrast, material specific images. The harmonic images of patterned silicon/silicon nitride control samples and triblock copolymers are presented. [ABSTRACT FROM AUTHOR]

A wavelength-selective optical switch based on waveguide grating routers (WGRs), passive splitters, and combiners is described. Tunable lasers on the transmitter side are the only active switching elements. The WGR is operated on multiple free-spectral ranges (FSRs) to achieve increased port count and switching capacity. Switching times of less than 24 ns between wavelengths covering three FSRs are demonstrated experimentally. [ABSTRACT FROM PUBLISHER]