Journal ArticleDOI
Laser speckle reduction by multimode optical fiber bundle with combined temporal, spatial, and angular diversity
TLDR
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.Abstract:
We report significant speckle reduction in a laser illumination system using a vibrating multimode optical fiber bundle. The optical fiber bundle was illuminated by two independent lasers simultaneously. The beams from both lasers were first expanded and collimated and were further divided into multiple beams to illuminate the fiber optic bundle with normal and oblique incidence. Static diffusers were also placed at the input and output faces of the fiber bundle, thus introducing the spatial as well as angular diversity of illumination. Experiments were carried out both in free space and in imaging geometry configuration. Standard deviation, speckle contrast and signal-to-noise ratio of the images were computed, and the results were compared with those of white light illumination. 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.read more
Citations
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Journal ArticleDOI
Efficient homogeneous illumination and optical sectioning for quantitative single-molecule localization microscopy.
TL;DR: This work has combined homogeneous multimode excitation of the sample with single-mode based TIR activation to simultaneously obtain the advantages of both approaches: uniform brightness of single fluorophores and TIR-like optical sectioning.
Journal ArticleDOI
Step-by-step guide to reduce spatial coherence of laser light using a rotating ground glass diffuser
TL;DR: A step-by-step guide for constructing a speckle-free and high-contrast laser illumination setup using a rotating ground glass diffuser driven by a stepper motor.
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.
Journal ArticleDOI
High-power homogeneous illumination for super-resolution localization microscopy with large field-of-view.
TL;DR: The flexible solution for realizing large FOV SRLM with a high-power homogeneous illumination system based on a newly designed multimode fiber combiner that is advantageous in laser power scaling and square-shape illumination without beam clipping is reported.
Journal ArticleDOI
Speckle reduction in laser projection using a dynamic deformable mirror
TL;DR: Speckle reduction by dynamic deformable mirror was investigated, and it was experimentally shown that speckle suppression can be attained by the widening of the spectrum of the lasers.
References
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Journal ArticleDOI
Some fundamental properties of speckle
TL;DR: In this paper, the distribution of scale sizes in a speckle pattern (i.e., the Wiener spectrum) is investigated from a physical point of view, and it is shown that adding M uncorrelated speckles on an intensity basis can reduce the contrast by 1/√M.
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.
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.
Journal ArticleDOI
Very efficient speckle contrast reduction realized by moving diffuser device
Shigeo Kubota,Joseph W. Goodman +1 more
TL;DR: Very efficient speckle contrast reduction is measured by temporal averaging using a moving diffuser on a tuning fork, which vibrates at 100 Hz over 60 microm in amplitude, a distance that is three times the surface roughness correlation length of the diffuser.
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Very efficient speckle contrast reduction realized by moving diffuser device
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