检索结果-南通市图书馆

Transmission Properties of One-Dimensional Photonic crystals Containing Anisotropic Metamaterials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第6期27卷 93-96页

作者： ZHANG Li-Wei YAN Ling-Ling ZHAO Yu-Huan LIU Li School of Physics and Chemistry Henan Polytechnic University Jiaozuo 454000 Pohl Institute of Solid State Physics Tongji University Shanghai 200092

The transmission properties of one-dimensional photonie crystals （1DPCs） containing anisotropic metamaterials are theoretically studied. It is shown that the 1DPCs can possess a similar zero average index （zero-n） gaps, the edges of zero-~ gap are weakly dependent on the incident angles, scale length and the polarization of the electromagnetic wave. When an impurity is introduced, a defect mode appears inside the zeron gap with a very weak dependence on incident angles and sealing. It is found that in such photonic crystals, a transmitted Gaussian pulse with its carrier frequency lying in the lower gap edge, in the defect mode and in the bandgap, can experience a positive or negative group delay and hence a subluminal, *** or superluminal propagation with small distortions. These properties of the photonic crystals have potential applications in the transfer of information.

关键词： crystal optics ANISOTROPY METAMATERIALS POLARIZATION of electromagnetic waves SCALING laws (Statistical physics) POINT defects GAUSSIAN processes ENERGY gaps (Physics)

Proposal of an Ultracompact Triplexer Using Photonic crystal Waveguide with an Air Holes Array

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第8期27卷 84-87页

作者：何灵娟徐旭明刘念华于天宝方利广廖清华 Department of Physics Nanchang University Nanchang 330031 Institute for Advanced Study Nanchang University Nanchang 330031 State Key Laboratory on Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083

We propose an ultracompact triplexer based on a shift of the cutoff frequency of the fundamental mode in a planar photonie crystal waveguide （PCW） with a triangular lattice of air holes. The shift is realized by modifying the radii of the border holes adjacent to the PCW core. Some defect holes are introduced to control the beam propagation. The numerical results obtained by the finite-difference time-domain method show that the presented triplexer can separate three specific wavelengths, i.e. 1310, 1490 and 1550nm with the extinction ratios higher than -18 dB. The designed device with a size as compact as 12 μm × 6.5μ m is feasible for the practical application, and can be utilized in the system of fiber to the home.

关键词： crystal optics OPTICAL waveguides crystal lattices PARTICLE beams FINITE differences TIME-domain analysis

All-normal-dispersion ps-pulse generation from high-gain ytterbium-doped photonic crystal fiber laser

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese optics Letters 2012年第B06期10卷 128-130页

作者：刘志李平雪池俊杰张雪霞 Institute of Laser Engineering Beijing University of Technology Beijing 100124 China

A fiber laser system emitting high-quality ultrashort powerful light pulses is reported. The photonic crystal fiber featuring high-gain large -mode-core and short absorption length is used, and the fiber laser is passively mode-locked by a semiconductor saturable absorber mirror. Its output greatly exceeds the power limitation of single-mode fiber oscillators with 1.4-W average power at 1 039-nm center wavelength, 6.9-ps pulse width, and 45.4-MHz repetition rate.

关键词： 140.2020 Diode lasers 260.1180 crystal optics 320.5390 Picosecond phenomena

Measurement of Optic Axis Direction Based on Interference Fringe Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Semiconductor Photonics and Technology 2006年第3期12卷 188-193页

作者： LI Wei-tao SHEN Wei-min WANG Yu-hong College of Optoelectronic ＆ Electrical Information Engineering Shanghai University of Science and Technology Shanghai 200093CHN Department of Optoelectronic Information Engineering China Jiliang University Hangzhou 310018 CHN

In order to conquer the defect in low precision and small range for measuring optic axial angle based on conoscopic interference method, interference fringe method is proposed. It is not the distance deviating from melatope but fringe numbers to decide optic axial angle. Fringe numbers are divided into integer portion and decimal fraction portion, the decimal fraction portion is calculated by non-linear interpolation method and integer portion is determined by the relative placement of interference fringes in the principal section. Extremum arithmetic of digit image is proposed and can be used to determine the interference fringes conveniently and precisely. After different niobate crystals were measured, the result shows that measurement range of optic axial angle is increased efficiently and measurement error is reduced to 0.1°.

关键词： crystal optics Conoscopic interference pattern Uniaxial crystal CCD camera Optic axis