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W. Shin - One of the best experts on this subject based on the ideXlab platform.

Young-chul Noh - One of the best experts on this subject based on the ideXlab platform.

David B. Phillips - One of the best experts on this subject based on the ideXlab platform.

  • High-speed polarisation shaping of arbitrary vector beams using a Digital Micro-Mirror device
    Conference on Lasers and Electro-Optics, 2017
    Co-Authors: Kevin J. Mitchell, Sergey Turtaev, Miles J. Padgett, Tomas Cizmar, David B. Phillips
    Abstract:

    We present the use of a Digital Micro-Mirror device to generate and rapidly switch between vector beams with spatially controllable intensity, phase and polarisation. We demonstrate this functionality by creating radially polarised, azimuthally polarised and Poincare beams at a frame rate of 4kHz.

  • High-speed spatial control of the intensity, phase and polarisation of vector beams using a Digital Micro-Mirror device
    Optics express, 2016
    Co-Authors: Kevin J. Mitchell, Sergey Turtaev, Miles J. Padgett, Tomáš Čižmár, David B. Phillips
    Abstract:

    The dynamic spatial control of light fields is essential to a range of applications, from Microscopy to optical Micro-manipulation and communications. Here we describe the use of a single Digital Micro-Mirror device (DMD) to generate and rapidly switch vector beams with spatially controllable intensity, phase and polarisation. We demonstrate local spatial control over linear, elliptical and circular polarisation, allowing the generation of radially and azimuthally polarised beams and Poincare beams. All of these can be switched at rates of up to 4kHz (limited only by our DMD model), a rate ∼2 orders of magnitude faster than the switching speeds of typical phase-only spatial light modulators. The polarisation state of the generated beams is characterised with spatially resolved Stokes measurements. We also describe detail of technical considerations when using a DMD, and quantify the mode capacity and efficiency of the beam generation. The high-speed switching capabilities of this method will be particularly useful for the control of light propagation through complex media such as multimode fibers, where rapid spatial modulation of intensity, phase and polarisation is required.

D.-k. Ko - One of the best experts on this subject based on the ideXlab platform.

William G Fateley - One of the best experts on this subject based on the ideXlab platform.

  • Handbook of Vibrational Spectroscopy - Hadamard Transform Near-Infrared Spectrometers
    Handbook of Vibrational Spectroscopy, 2006
    Co-Authors: Robert M Hammaker, Richard A. Deverse, Daniel J. Asunskis, William G Fateley
    Abstract:

    Hadamard transform (HT) spectrometry is introduced using a 3-resolution element example to illustrate the operation of an HT spectrometer and its multiplex advantage leading to an improved signal-to-noise ratio (SNR). The Hadamard encoding mask is described and the Digital Micro-Mirror array (DMA) is introduced and described to demonstrate that the DMA is an attractive choice for the Hadamard encoding mask. A near-infrared DMA spectrometer and some of its features are described and its SNR advantage relative to a classical scanning dispersive spectrometer is demonstrated experimentally. The potential for the combination of the DMA with a single-element detector to provide an important advancement in spectroscopic instrumentation is indicated. Keywords: Hadamard transform spectrometer; Hadamard encoding mask; Digital Micro-Mirror array

  • The other spectroscopy: demonstration of a new de-dispersion imaging spectrograph
    Vibrational Spectroscopy, 2002
    Co-Authors: William G Fateley, R A Deverse, R.m. Hammaker, R.r Coifman, F.b Geshwind
    Abstract:

    A Digital Micro-Mirror array (DMA) and a single-element detector comprise a versatile near-infrared (NIR) imaging spectrograph. The spatial/spectral resolution elements produced by the imaging spectrograph operated in a de-dispersive mode can be processed in a variety of ways to provide great flexibility in method and application.

  • hadamard transform raman imagery with a Digital Micro Mirror array
    Vibrational Spectroscopy, 1999
    Co-Authors: R A Deverse, Robert M Hammaker, William G Fateley
    Abstract:

    Abstract Our previous efforts in Hadamard transform Raman imaging in the visible spectral region began with stationary two-dimensional (2D) Hadamard encoding masks and evolved to moving 2D Hadamard encoding masks. We have now advanced to using a spatial light modulator developed by Texas Instruments, herein called a Digital Micro-Mirror array (DMA), as a computer-controlled 2D Hadamard encoding mask. The aluminized Mirrors in the DMA are 16 um square and rotatable by ±10° from an intermediate position. The +10° position of a Micro-Mirror directs its spatial resolution element onto the detector and the −10° position of a Micro-Mirror directs its spatial resolution element away from the detector. The heterogeneous samples investigated were three layers of immiscible liquids (benzene–water–nitrobenzene) and a layer of solid benzoic acid stuck to a piece of double sided tape with a 1.0 mm 2 chip of naphthalene pressed onto the layer of benzoic acid near one corner of the benzoic acid layer. Macroscopic images of the various components in these samples have been generated with a spatial resolution of 340 um. Spectra of individual pixels at the sample plane have been obtained for the sample of immiscible liquids. Images of liquid and solid heterogeneous samples and spectra of individual pixels at the sample plane can be obtained by Hadamard transform Raman imaging using a DMA as a 2D Hadamard encoding mask that operates rapidly and reliably.