Focusing coherent light through opaque strongly scattering media

ArticleinOptics Letters 32(16):2309-11 · September 2007with55 Reads
DOI: 10.1364/OL.32.002309 · Source: PubMed
Abstract
We report focusing of coherent light through opaque scattering materials by control of the incident wavefront. The multiply scattered light forms a focus with a brightness that is up to a factor of 1000 higher than the brightness of the normal diffuse transmission.
    • "Via holography, the phase and amplitude of a wavefront can be manipulated, allowing to use complex wavefronts. Moreover, the path of the light can be corrected for disturbances using wavefront-shaping methods [27]. The SLM is programmed with horizontal and vertical gratings to scan over the detection plane of the ICCD. "
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    Article · Sep 2016 · Journal of optics
    • "The aim of this study is to develop a new approach to the problem of the DOE dynamic synthesis via SLM. To achieve the claimed result, the algorithm of optical wavefront adaptive optimization will be used [12]. This algorithm was created to solve the problem of optical beam focusing through randomly scattering media. "
    [Show abstract] [Hide abstract] ABSTRACT: Nowadays, the most advanced technology of diffractive optical elements (DOE) synthesis is a dynamic spatial light modulator (SLM). Herewith this kind of devices is divided into liquid-crystal (LCD SLM) and micro-electromechanical (ME SLM) systems. Light field synthesis methods using dynamic DOE provide solutions of problems that require complex configuration of the optical field, such as laser beam shaping [1], digital holography applications [2], the formation and transmission of optical information [3], micro-objects and biological cells manipulation [4]. The primary function of the DOE is a synthesis of required optical field distribution in a predetermined domain (target-region). The specified target-area can act as flat or curved surface [5, 6], as well as three-dimensional domain [7]. From the scalar diffraction theory, it is well known that the distribution of the optical beam intensity can be adjusted by the boundary conditions that describe the wavefront. Thus, the main objective for a synthesis of the optical field in the output target-region is to locate the appropriate field distribution in the surface of specified input plane (DOE installation plane) and then manipulate produced wavefront with dynamic DOE. The boundary condition of the wavefront surface can be realized by ribbed DOEs [8], holographic optical elements (HOEs) [9], digital holograms recorded on films [10], and the dynamic DOE – SLM of phase type. A more detailed review of the DOEs is presented in [11]. The aim of this study is to develop a new approach to the problem of the DOE dynamic synthesis via SLM. To achieve the claimed result, the algorithm of optical wavefront adaptive optimization will be used [12]. This algorithm was created to solve the problem of optical beam focusing through randomly scattering media. Previously an elementary case was considered when there is no scattering medium in the object plane [13]. The developed approach to the synthesis of the DOE was used to set the amplitude distribution in the target-plane.
    Full-text · Conference Paper · Sep 2016 · Journal of optics
    • "Finally, the contrast may be increased by using a nonlinear contrast mechanism, such as multi-photon fluorescence. Since the contrast scales linearly with the number of pixels on the light modulator [62], the contrast can be increased by simply having more pixels on the SLM. Here lies a challenge for industry to manufacture light modulators with tens of megapixels. "
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    Article · Sep 2016
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Comment

September 30, 2015
Seneca College
Interesting work which has alot of potential.

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