Ji'an Duan

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Achieving narrow resonance is an area of interest within the field of metamaterials. However, only a few studies have investigated the polarization-insensitive resonances. A general principle for improving quality Q-factor of a sharp resonance is still unclear. In this work, we proposed a kind of planar meta-molecule metamaterials, which can exhibit(More)
This paper proposes an efficient approach for production-rate enhancement and size reduction of silicon nanoparticles produced by femtosecond (fs) double-pulse ablation of silicon in ethanol. Compared with a single pulse, the production rate is ~2.6 times higher and the mean size of the NPs is reduced by ~1/5 with a delay of 2 ps. The abnormal enhancement(More)
To achieve less than 50 N soft-landing using magneto-rheological fluid (MRF) damper, a novel small-MRF damper has been developed. First, we design a new outer electromagnetic coil comparing with traditional inner coil structure, which can obtain miniature damper easily and control the magnetic field conveniently. Second, we apply silicon steel rather than(More)
The construction and design of a mixed magnetic bearing with 5 DOFs (degree-of-freedoms) is introduced in this paper. The bearing can be stabilized in all five DOFs by only one DOF feedback control in the axis direction, the other DOFs are controlled passively by permanent magnetic bearings. The carrying stiffness matrix of the bearing is calculated and its(More)
We demonstrate an efficient method for fabricating high-quality cylindrical microlens arrays (CMLAs) on the surface of fused silica, fully based on spatially shaping of a femtosecond laser beam from Gaussian to Bessel distribution. As the envelope of shaped spatial intensity distribution matches the profile of cylindrical microlens perfectly, a CMLA with(More)
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