Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences
Not a member yet
13355 research outputs found
Sort by
Containing intense laser light in circular cavity with magnetic trap door
No full textNNSFC [11305264, 11275269, 11374262, 11375265, 11475260, 91230205]; Open Fund of the State Key Laboratory of High Field Laser Physics at SIOM; Research Program of NUDTIt is shown by particle-in-cell simulation that intense circularly polarized (CP) laser light can be contained in the cavity of a solid-density circular Al-plasma shell for hundreds of light-wave periods before it is dissipated by laser-plasma interaction. A right-hand CP laser pulse can propagate with almost no reflection and attenuation into the cavity through a highly magnetized overdense H-plasma slab filling the entrance hole. The entrapped laser light is then multiply reflected at the inner surfaces of the slab and shell plasmas, slowly losing energy to the latter. Compared to that of the incident laser, the frequency is only slightly broadened and the wave vector slightly modified by the appearance of weak nearly isotropic and homogeneous fluctuations. Published by AIP Publishing
Crater-like structures induced by intense laser
No full textNational Natural Science Foundation of China [11125526, 11335013, 11575274]; Strategic Priority Research Program of the Chinese Academy of Sciences [XDB16]; Ministry of Science and Technology of the People's Republic of China [2016YFA0401102]Crater-like structures are experimentally studied with an ultrashort, ultraintense laser pulse with an intensity of 1.5 x 10(18) W/cm(2), irradiating borosilicate glass targets, which extends laser-induced craters to the region of relativistic intensities. The morphology of the crater-like structures is measured accurately using a three-dimensional laser scanning confocal microscope and a scanning electron microscope. The experimental results indicate that a circular bowl shape is formed with a depth-to-diameter ratio of about 1/5, which is similar to that of meteorite impact craters. A plasma fireball model is applied to analyze the experimental results. Studies show that catastrophic asteroid strikes may be investigated by irradiating foils with intense laser pulses. (C) 2017 Author(s)
Fabrication of polarization-independent waveguides deeply buried in lithium niobate crystal using aberration-corrected femtosecond laser direct writing
No full textNational Basic Research Program of China [2014CB921300]; National Natural Science Foundation of China [61590934, 11134010, 21375139, 61327902]; Youth Innovation Promotion Association of Chinese Academy of SciencesWriting optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1400 mu m, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing
Highly compact CsPbBr3 perovskite thin films decorated by ZnO nanoparticles for enhanced random lasing
No full textNational Natural Science Foundation of China (NSFC) [61404017, 61475169]; Chongqing Postdoctoral Science Research Special Funded Project [Xm2016017]; Natural Science Foundation of Chongqing [cstc2017jcyjB0273]; 100 Talents Program of Chinese Academy of Sciences (CAS); Strategic Priority Research Program of CAS [XDB1603]Inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) have attracted enormous attention as a novel optoelectronic material with enhanced stability. However, the perovskite CsPbX3 thin films fabricated by onestep spin-coating method contain the defects of voids or pinholes, seriously affecting their amplified spontaneous emission (ASE) or lasing performance. To solve this issue, herein, we demonstrate that by simply introducing ZnO nanoparticles (NPs) into the CsPbBr3 precursor solution, the CsPbBr3:ZnO films synthesized by one-step spin-coating method exhibit enhanced crystallization, improved photoluminescence (PL) intensity and prolonged lifetime. Introducing the ZnO NPs can provide an effective route for CsPbBr3 nucleation during the spin-coating and annealing process, contributing to compact and smooth thin films with no obviously large voids or pinholes. Under the one-photon (400 nm) and two-photon (800 nm) femtosecond laser excitation, the ASE of CsPbBr3 and CsPbBr3:ZnO films have been investigated at room temperature, respectively. After the film compactness, surface smoothness and crystal size are modified by the ZnO additive, both the emission efficiency and the ASE threshold of the CsPbBr3:ZnO films have been improved in comparison with the pure CsPbBr3 films
Monolithic integration of a lithium niobate microresonator with a free-standing waveguide using femtosecond laser assisted ion beam writing
No full textNational Basic Research Program of China (Program 973) [2014CB921300]; Natural National Science Foundation of China (NSFC) [61505231, 61405220, 61327902, 61590934]; Fundamental Research Funds for the Central Universities and the Open Fund of the State Key Laboratory on Integrated Optoelectronics [IOSKL2015KF34]We demonstrated integrating a high quality factor lithium niobate microdisk resonator with a free-standing membrane waveguide. Our technique is based on femtosecond laser direct writing which produces the pre-structure, followed by focused ion beam milling which reduces the surface roughness of sidewall of the fabricated structure to nanometer scale. Efficient light coupling between the integrated waveguide and microdisk was achieved, and the quality factor of the microresonator was measured as high as 1.67 x 10(5)
Active Dual-Wavelength Optical Switch-Based Plasmonic Demultiplexer Using Metal-Kerr Nonlinear Material-Metal Waveguide
No full textTo realize active light control with a compact structure, a nanoscale optical switch-based plasmonic demultiplexer is proposed. The device is designed according to the metal-Kerr nonlinear material-metal waveguide with multiple resonant cavities, providing the capability of active optical regulation for dual wavelengths: Signals of 1310 and 1550 nm can be guided into either output with high directional extinction ratios larger than 30 dB controlled by another pump light of 730 nm with low power. Considering its light control capability and compact configuration, it is believed that the proposed demultiplexer can be adopted in the future logic plasmonic circuits
Facial color measurement based on camera colorimetric characterization
No full textThe objective measurement of facial skin color and its variance is of great significance as much information can be obtained from it. In this paper, we developed a new skin color measurement procedure which includes following parts: first, a new skin tone color checker made of pantone Skin Tone Color Checker was designed for camera colorimetric characterization; second, the chromaticity of light source was estimated via a new scene illumination estimation method considering several previous algorithms; third, chromatic adaption was used to convert the input facial image into output facial image which appears taken under canonical light; finally the validity and accuracy of our method was verified by comparing the results obtained by our procedure with these by spectrophotometer
Research on a grating interferometer with high optical subdivision based on quasi-Littrow configuration
No full textA grating interferometer is presented based on the quasi-Littrow configuration. We mainly use a plane mirror to make the measuring light reflect and diffract between the mirror and grating scale for several times. According to the grating Doppler shift, the more times that measuring light diffracted, the higher optical subdivision can be obtained. As an example, a grating interferometer with an optical subdivision factor of 1/12 is designed. This work provides a technique to increase the resolution of the grating interferometer, which should be interesting for high precision measurement
Design and analysis of broadband diffractive optical element for achromatic focusing
No full textThe achromatic diffractive optical element (DOE) was numerically studied. The light intensity distribution in the focal plane was studied by the vectorial diffraction theory, then the radially symmetric DOE to enable broadband achromatic focusing with low sidelobe intensity ratios and uniform central intensities were optimized by the simulated annealing (SA) algorithm. The plane wave with wavelength of 486nm, 588nm, and 656nm were used in our optimization and numerical research. Three DOEs with 60, 80, and 100 transition points were obtained. Numerical results shown that the sidelobe intensity suppression ratios of focal spots of these wavelengths are all less than 0.12, the principal peaks' intensities differences and spots' sizes differences of these focal spots are all less than 5% and 10%, respectively. The designed DOEs were polarization insensitive