Journal ArticleDOI
Laser speckle reduction due to spatial and angular diversity introduced by fast scanning micromirror.
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TLDR
Experimental results show that the speckle contrast factor can be reduced down to 5% within the integration time of the detector.Abstract:
We utilize spatial and angular diversity to achieve speckle reduction in laser illumination. Both free-space and imaging geometry configurations are considered. A fast two-dimensional scanning micromirror is employed to steer the laser beam. A simple experimental setup is built to demonstrate the application of our technique in a two-dimensional laser picture projection. Experimental results show that the speckle contrast factor can be reduced down to 5% within the integration time of the detector.read more
Citations
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Journal ArticleDOI
Low spatial coherence electrically pumped semiconductor laser for speckle-free full-field imaging
Brandon Redding,Alexander Cerjan,Xue Huang,Minjoo Larry Lee,A. Douglas Stone,Michael A. Choma,Hui Cao +6 more
TL;DR: A chip-scale, electrically pumped semiconductor laser based on a novel design is presented, demonstrating high power per mode with much lower spatial coherence than conventional laser sources, which could enable a wide range of full-field imaging applications.
Journal ArticleDOI
Complex lasers with controllable coherence
TL;DR: In this paper, the authors present an overview of complex, low and tunable spatial coherence properties of laser cavity geometries with a focus on their spatial and spectral properties.
Journal ArticleDOI
Laser speckle reduction by multimode optical fiber bundle with combined temporal, spatial, and angular diversity
TL;DR: Speckle contrast close to that of white light was obtained using a vibrating fiber bundle with combined temporal, spatial, and angular diversities of the illumination.
Journal ArticleDOI
Speckle noise suppression in digital holography by angular diversity with phase-only spatial light modulator
TL;DR: The experimental results demonstrate the effectiveness, repeatability, and practicability of the proposed approach, and the greatly suppressed speckle noise which is in good agreement with the theoretical results.
Journal ArticleDOI
Speckle reduction and maintaining contrast in a LASER pico-projector using a vibrating symmetric diffuser
Jui-Wen Pan,Chi Hao Shih +1 more
TL;DR: A design for a LASER pico-projector with a low speckle contrast value and high contrast ratio that maintains system efficiency is proposed and utilizes two diffusers and a Voice Coil Motor (VCM) oscillator.
References
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Journal ArticleDOI
Speckle Reduction in Laser Projection Systems by Diffractive Optical Elements
TL;DR: A new method for eliminating speckles in the far field by using a diffractive optical element is proposed, which can be reduced to a few percent while good beam quality is preserved.
Journal ArticleDOI
Speckle Removal by a Slowly Moving Diffuser Associated with a Motionless Diffuser
Serge Lowenthal,Denis Joyeux +1 more
TL;DR: In this article, a two-diffuser system of which one diffuser is motionless, the other moving is used to destroy the spatial coherence of laser light only partially when the integration time is finite.
Proceedings ArticleDOI
Speckle contrast reduction in laser projection displays
TL;DR: In this paper, the maximum speckle contrast reduction for a given system was derived, and two novel approaches to achieve the maximum reduction were introduced, and the Hadamard diffuser was applied to the GLV TM.
Journal ArticleDOI
Speckle Reduction Using Multiple Tones of Illumination
Nicholas George,Atul Jain +1 more
TL;DR: A direct extension of this method to holographic microscopy, using a multitone laser, should permit one to record and reconstruct holograms of diffraction-limited resolution that are essentially speckle-free.
Journal ArticleDOI
Hadamard speckle contrast reduction
TL;DR: The condition for a diffuser to produce the maximum speckle contrast reduction with the minimum number of distinct phase patterns is derived and a binary realization of this optimum diffuser is obtained by mapping the rows or columns of a Hadamard matrix to the phase patterns.
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