共查询到20条相似文献,搜索用时 31 毫秒
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ANovelMethodofSelectingSLM──PhaseRetardationofaBirefringentCrystal¥SHENXiaohua;CHENShaohe;LINZunqi(ShanghaiInstituteofOpticsa... 相似文献
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R. Bowman N. Muller X. Zambrana-Puyalto O. Jedrkiewicz P. Di Trapani M. J. Padgett 《The European physical journal. Special topics》2011,199(1):159-166
We use a Spatial Light Modulator (SLM) to produce arrays of Bessel beams by using multiple axicon phase-masks on the SLM.
This approach utilises the whole of the SLM, rather than just a thin annular region (which is the case if the SLM is in the
far-field of the generated Bessel beams). Using the whole SLM rather than just an annular region means that the required intensity
on the SLM is an order of magnitude lower for a given power in the Bessel beams. Spreading the power over the whole SLM is
important for high-power applications such as laser micromachining. We allow the axicons to overlap and interfere in the hologram,
so the axial length of the Bessel beam core is maintained as we add more beams to the array. 相似文献
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An all-solid-state single-longitudinal-mode (SLM) laser at 500.8 nm with 830 mW output power has been demonstrated for the
first time. By using a new resonator for doubly resonant, Nd:GdVO4 and Nd:YAG were pumped by two laser diode arrays coupled by optical fiber, respectively. In the two sub-cavities, SLM wavelengths
of 1064 and 946 nm were induced by using the twisted-mode technique and then mixed into SLM 500.8 nm laser with sum-frequency
technology. The SLM 500.8 nm laser output of 830 mW was obtained at the incident pump power of 20 W for Nd:GdVO4 and 23 W for Nd:YAG. The experimental results showed that the intracavity sum-frequency mixing by twisted-mode technique
is an effective method for SLM 500.8 nm laser. 相似文献
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A new method of generation of two dimensional vortex lattices is described. In this method, different parts of the wavefront are given different local tilts to realize vortex lattice in the propagated field. These linear phase variations corresponding to tilts in different locations of the wavefront are created using a spatial light modulator (SLM). The diffracted field from the SLM is found to contain vortex lattice and the presence of these vortices is confirmed experimentally. Computational results are also provided. 相似文献
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《中国光学快报(英文版)》2018,(10)
In liquid crystal spatial light modulator(SLM)-based holographic projection, the image is usually displayed at a distant projection screen through free space diffraction from a computer-generated hologram(CGH). Therefore,it allows for removing of the projection lens for the sake of system simplification and being aberration free, known as the "lensless holographic projection". However, the maximum size of the optical projected image is limited by the diffraction angle of the SLM. In this Letter, we present a method for the implementation of image magnification in a lensless holographic projection system by using convergent spherical wave illumination to the SLM.The complete complex amplitude of the image wavefront is reconstructed in a lensless optical filtering system from a phase-only CGH that is encoded by the off-axis double-phase method. The dimensions of the magnified image can break the limitation by the maximum diffraction angle of the SLM at a given projection distance.Optical experiment results with successful image magnification in the lensless holographic projection system are presented. 相似文献
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Norihiro Fukuchi Ye Biqing Yasunori Igasaki Narihiro Yoshida Yuji Kobayashi Tsutomu Hara 《Optical Review》2005,12(5):372-377
We have developed optically-addressed and electrically-addressed liquid crystal spatial phase-only light modulators having
no pixelized structures. We obtained a large depth of phase-only modulation and high diffraction efficiency based on the electro-optical
characteristics of a parallel-aligned nematic liquid crystal. These spatial light modulators (SLM) are of the reflection type,
so there would be a loss of power in the readout light from the half mirror, which was set up so as to separate the incident
and reflected lights. To optimize the characteristics of a reflection type spatial phase-only light modulator, we have proposed
an oblique incident optical readout setup. We have examined the effect of conditions such as the polarization direction and
the incidence angle of the readout light, and the orientation of liquid crystal molecules in the SLM. High diffraction efficiency
close to the theoretical maximum value was obtained by adjusting the above conditions. The simulation analysis can well explain
the experimental results of phase modulation. 相似文献
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A. Calatayud J. A. Rodrigo L. Remón W. D. Furlan G. Cristóbal J. A. Monsoriu 《Applied physics. B, Lasers and optics》2012,106(4):915-919
We propose the first experimental approach for both generation and characterization of high quality Devil’s vortex-lenses.
These new type of lenses, able to produce a sequence of optical vortices, are addressed onto a programmable spatial light
modulator (SLM) operating in phase-only modulation. The static aberrations arising by the lack of flatness of the SLM display
are characterized and mostly compensated by using a Shack–Hartmann wavefront sensor. The analysis of the residual aberrations
and their effect on the vortex-lens performance are studied. 相似文献
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A readout function of a reading light supplier (RLS) is demonstrated by reading out images from an optical addressable spatial light modulator (SLM). The RLS supplies reading light to the reading side of the SLM and transmits readout images from the SLM. The RLS consists of a fiber plate and a redirector which has micro conical-hollows. The RLS contrast, which is the intensity ratio of the reading light to the stray light, is 9.2 and the power efficiency of the reading light supply is about 5%. A writing pattern on the SLM is a checkered pattern of 5 mm×5 mm cells, and it is read out successfully using the RLS. The maximum contrast of the readout image is 1.9. 相似文献
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菲涅尔非相干相关全息术(Fresnel incoherent correlation holography, FINCH)通过空间光调制器(spatial light modulator, SLM)将来自物点的光波分解为曲率半径不同的两束自相干光,干涉条纹由CCD记录.由于受限于SLM与CCD的像素数目及像素尺寸, FINCH技术与光学全息术相比记录视场要小得多.本文通过对FINCH系统的记录过程进行理论分析,给出了SLM所能记录的视场角,说明通过调控加载在SLM上的双透镜光轴中心,能够扩大SLM的有效直径从而将SLM的有效记录范围增大2.77倍,有效扩大了系统的记录视场.搭建了非相干光反射式数字全息记录系统并对理论分析进行了实验验证,结果表明:在SLM上依次加载不同光轴中心位置的双透镜掩模进行FINCH记录及再现,将得到的各子图像拼接融合可以得到高分辨率大视场图像,为菲涅尔非相干全息术在高分辨大视场显微成像的进一步应用提供了有力支撑. 相似文献
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Since the introduction of computer-controlled spatial light modulators (SLMs), holographic optical tweezers have become an
important tool for dynamic parallel optical manipulation. In this paper we clarify the usefulness of a new configuration for
optical trapping that creates light patterns using the combination of a diffractive optical element (DOE) and an SLM. This
configuration not only enables the use of the higher part of the SLM’s diffraction efficiency curve, because a simple hologram
can be chosen for the SLM, but also achieves three-dimensional dynamic optical manipulation over a large spatial range. By
switching blaze-like holograms displayed on the SLM, we demonstrated simultaneous transportation of three 6-μm-diameter polystyrene
beads over a range of 90 μm in the vertical direction and 37.5 μm in the horizontal direction. Compared with the same manipulation
executed using only the SLM, the range of this method is extended four-fold in the vertical direction and three-fold in the
horizontal direction. 相似文献
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Sasidhar Chavali Philip M. Birch Rupert Young Chris Chatwin 《Optics and Lasers in Engineering》2007,45(3):413
Achieving phase only modulation from a spatial light modulator (SLM) is useful for many optical processing tasks. In this paper, we demonstrate a simple method of decoupling phase and amplitude modulation in a twisted nematic liquid crystal (TNLC) SLM using a double pass technique. A Jones calculus model is developed which matches our experimental data. 相似文献
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The liquid crystal spatial light modulator (LC SLM) is very suitable
for wavefront correction and optical testing and can produce a
wavefront with large phase change and high accuracy. The LC SLM is
composed of thousands of pixels and the pixel size and shape have
effects on the diffractive characteristics of the LC SLM. This paper
investigates the pixel effect on the phase of the wavefront with the
scalar diffractive theory. The results show that the maximum optical
path difference modulation is 41\,$\mu$m to produce the paraboloid
wavefront with the peak to valley accuracy better than $\la$/10.
Effects of the mismatch between the pixel and the period, and black
matrix on the diffraction efficiency of the LC SLM are also analysed
with the Fresnel phase lens model. The ability of the LC SLM is
discussed for optical testing and wavefront correction based on the
calculated results. It shows that the LC SLM can be used as a
wavefront corrector and a compensator. 相似文献
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Yurko Duda Ian Garcia Andrij Trokhymchuk Douglas Henderson 《Molecular physics》2013,111(17):1287-1293
The structure of a starlike molecule (SLM) fluid with four arms of different length is studied by applying the associative Percus–Yevick integral equation (IE) theory and canonical Monte Carlo (MC) simulations. In the IE study the SLM fluid is modelled by a fluid of hard spheres with four associative sites on each sphere while the MC has been performed for a freely-joined tangent hard sphere fluid. The total radial distribution functions have been calculated in both approaches for different volume fraction regimes and different arm lengths. It is shown that the associative IE theory predicts the structure of SLM fluid best for relatively long arms and at high densities. Additionally, the dependence of the SLM centre–centre correlations on the functionality and fluid particle density has been analysed using the MC results. 相似文献
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Jorge L. Flores Guillermo Garcia-Torales Juan P. Aguayo-Adame Jose A. Ferrari 《Optik》2012,123(12):1067-1070
We describe an auto programmable spatial-filtering system using photochromic glass plate as a programmable spatial light modulator, SLM, illuminated by a single wavelength of light. The proposed setup is a conventional 4f coherent optical system. At Fourier plane the filter function is written on the SLM as negative copy of the power spectrum of the input image. The method does not involve numerical processing, and thus, it could be potentially useful for processing large images. Validation experiments are presented. 相似文献
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As the light source of the coherent Doppler LIDAR, a single-longitudinal-mode (SLM) with narrow linewidth and high frequency
stability are typically required as the seed laser of the injection locking systems. Many scholars make point on the research
about SLM selection in laser diode pumped all solid states lasers on theoretically and experimentally. In this paper, we will
introduce and discuss the SLM selection work on 2 μm SLM lasers. SLM selection methods mainly include micro-cavity, double
cavities, ring laser, inserting F-P etalons into the cavity, inserting birefringent filter into the cavity and so on. The
advantages and disadvantages of these methods will be generalized and discussed. 相似文献
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Yuanhu Wang Yanchen Qu Weijiang Zhao Chenghong Jiao Zhiqiang Liang Deming Ren 《Optics Communications》2009,282(8):1615-1618
An effective single-longitudinal mode (SLM) pulse TEA CO2 laser operation was demonstrated using a Michelson’s type resonator with a tilting Fabry-Perot etalon. A modified numerical model of the interference resonator was investigated for designing the laser. The experimentally measured values were found to have good agreement with the numerical model. A pulse width of about 90 ns and the maximum pulse energy of about 300 mJ were achieved at 10.59 μm in SLM and TEM00 mode. The reliability of producing SLM pulses was 100% and there was no damage on the etalon. By turning the interference resonator, the SLM output was tuned 44 lines of the CO2 spectrum. 相似文献