Design, Modeling, and Characterization of a Microelectromechanical Diffuser Device for Laser Speckle Reduction

54‐1: Laser Speckle Reduction using Nanoparticle‐Embedded Liquid Crystals

“…There are several solutions proposed to reduce laser speckles based on the decorrelation at the perspectives of wavelength, spatial, angular, and polarization. The majority of the proposed solutions are introducing optical components such as diffuser, microlens-array beam shaper, phase matrix and optical fibers with mechanical motion such as rotation or vibration in the system to reduce the coherence of light source [4][5][6][7][8]. Motionless optical components for speckle reductions are demonstrated such as polymer dynamic diffraction gratings, deformable mirrors, scattering from colloidal suspension, spatial light modulator, and ferroelectric liquid crystal cell [9][10][11][12][13].…”

Development of Zinc Oxide Spatial Light Modulator for High-Yield Speckle Modulation

“…Moreover, for the future application to the speckle reduction, we focused on high-speed modulation of speckle patterns by utilizing beam shifts of incident plane-wave light due to modulation of the spatial distribution of the refractive index. While the conventional approaches [11]- [25] require a mechanical setup to realize high-speed fluctuation of the displayed screen, the main advantage of our idea is the high speed achieved by a compact setup that does not require any mechanical elements, which lower the stability and durabil-ity of the conventional set-ups.…”

“…On the other hand, because the human eye obtains an image over a certain exposure time, speckle patterns that are modulated at sufficiently high speed are time-averaged and become uniform. In such a case, the observer cannot recognize any speckle pattern [11]- [25]. In this paper, as the earliest stages of the latter approach, we exhibit a novel device, which is developed and operates with an original mechanism based on basics of nano-photonics, to modulate speckle patterns.…”

P‐222:Late‐News‐Poster:Mechanically‐Static Laser Speckle Reduction Solution

“…The target for a speckle reduction solution is to reduce the speckle contrast to the level below the detection limit. Several solutions are proposed based on the temporal decoherence approach, for example, mechanically vibrating or rotating an optical component such as diffuser, microlens array, phase matrix and/or optical fibers [8][9][10][11][12]. Motionless approaches have also been demonstrated by using a polymer dynamic diffraction grating, colloidal suspension, spatial light modulator, ferroelectric liquid crystal (LC), LC with chiral dopant, and nanoparticle (NP)-doped LC devices [13][14][15][16][17][18].…”