Beam generator of 4-channel with zeroth order suppressed by reflective T-type grating

2021 ◽  
pp. 2150218
Author(s):  
Chen Fu ◽  
Bo Wang ◽  
Zefan Lin ◽  
Zhisen Huang ◽  
Kunhua Wen ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Propagation Mechanism ◽  
Total Efficiency ◽  
The Finite Element Method ◽  
Zeroth Order ◽  
Beam Splitting ◽  
Manufacturing Tolerance ◽  
Dielectric Grating ◽  
Good Uniformity ◽  
Better Than

Four-port beam splitter with good uniformity was proposed by T-type double-layer with different dielectric grating. The total efficiency of the beam splitter is over 90% with beam splitting uniformity better than 3%. At the same time, the simplified modal analysis is added to calculate the grating mode and effective refractive index of the grating area, which clearly describes the physical propagation mechanism inside the grating. The finite element method is used to investigate the normalized field of the grating, which more intuitively reflects the way of energy transfer inside the grating. Finally, the incident characteristics and manufacturing tolerance of the grating are analyzed. Properties of the T-type grating were analyzed in three methods, which more fully illustrates the applicability and stability of the grating in this paper.

scholarly journals Diffraction mechanism of five-port transmission gratings

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Chenhao Gao ◽  
Bo Wang ◽  
Kunhua Wen ◽  
Ziming Meng ◽  
Qu Wang ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Diffraction Order ◽  
Normal Incidence ◽  
Propagation Mechanism ◽  
Beam Splitting ◽  
Transmission Grating ◽  
Process Tolerance ◽  
Wide Range ◽  
Rigorous Coupled Wave ◽  
Modal Method

This paper designs a five-port transmission grating under normal incidence. Rigorous coupled-wave approach is used to optimize the grating parameters. The energy of the grating is mainly dispersed to the 0th, ±1st and ±2nd orders. The efficiency of each diffraction order under both polarizations is close to 20%. The modal method is used to describe the propagation mechanism of the two polarized lights in the grating, and the diffraction behavior of the grating is analyzed. In addition, the grating has a wide range of incident characteristics and a large process tolerance. Therefore, this five-port beam splitter with a connecting layer will be a good polarization-independent beam splitting device.

Development of 200kV ultrahigh-resolution analytical electron microscope

1989 ◽  
Vol 47 ◽  
pp. 108-109
Author(s):  
T. Kaneyama ◽  
M. Naruse ◽  
Y. Ishida ◽  
M. Kersker
Keyword(s):  
Electron Microscope ◽  
Optical Constants ◽  
Materials Science ◽  
Objective Lens ◽  
The Finite Element Method ◽  
Ultrahigh Resolution ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Characteristic Features ◽  
Better Than

In the field of materials science, the importance of the ultrahigh resolution analytical electron microscope (UHRAEM) is increasing. A new UHRAEM which provides a resolution of better than 0.2 nm and allows analysis of a few nm areas has been developed. [Fig. 1 shows the external view] The followings are some characteristic features of the UHRAEM.Objective lens (OL)Two types of OL polepieces (URP for ±10' specimen tilt and ARP for ±30' tilt) have been developed. The optical constants shown in the table on the next page are figures calculated by the finite element method. However, Cs was experimentally confirmed by two methods (namely, Beam Tilt method and Krivanek method) as 0.45 ∼ 0.50 mm for URP and as 0.9 ∼ 1.0 mm for ARP, respectively. Fig. 2 shows an optical diffractogram obtained from a micrograph of amorphous carbon with URP under the Scherzer defocus condition. It demonstrates a resolution of 0.19 nm and a Cs smaller than 0.5 mm.

scholarly journals Compact Photonic Crystal Polarization Beam Splitter Based on the Self-Collimation Effect

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 198
Author(s):  
Geyu Tang ◽  
Huamao Huang ◽  
Yuqi Liu ◽  
Hong Wang
Keyword(s):  
Optical Communications ◽  
Beam Splitter ◽  
Extinction Ratio ◽  
Polarized Light ◽  
The Self ◽  
Polarization Beam Splitter ◽  
Optical Interconnection ◽  
Beam Splitting ◽  
Beam Splitters ◽  
Polarization Extinction Ratio

We propose a new compact polarization beam splitter based on the self-collimation effect of two-dimensional photonic crystals and photonic bandgap characteristics. The device is composed of a rectangular air holes-based polarization beam splitting structure and circular air holes-based self-collimating structure. By inserting the polarization beam splitting structure into the self-collimating structure, the TE and TM polarized lights are orthogonally separated at their junction. When the number of rows in the hypotenuse of the inserted rectangular holes is 5, the transmittance of TE polarized light at 1550 nm is 95.4% and the corresponding polarization extinction ratio is 23 dB; on the other hand, the transmittance of TM polarized light is 88.5% and the corresponding polarization extinction ratio is 37 dB. For TE and TM polarized lights covering a 100 nm bandwidth, the TE and TM polarization extinction ratios are higher than 18 dB and 30 dB, respectively. Compared with the previous polarization beam splitters, our structure is simple, the size is small, and the extinction ratio is high, which meets the needs of modern optical communications, optical interconnection, and optical integrated systems.

High-Precision Polarizing Beam Splitting System Based on Polarizing Beam Splitter

2016 ◽  
Vol 43 (12) ◽  
pp. 1210001
Author(s):  
罗敬 Luo Jing ◽  
刘东 Liu Dong ◽  
徐沛拓 Xu Peituo ◽  
白剑 Bai Jian ◽  
刘崇 Liu Chong ◽  
...  
Keyword(s):  
High Precision ◽  
Beam Splitter ◽  
Beam Splitting ◽  
Polarizing Beam Splitter ◽  
Splitting System

A novel beam splitter based on graded photonic crystals

2014 ◽  
Vol 28 (23) ◽  
pp. 1450171 ◽  
Author(s):  
L. H. Wang ◽  
X. L. Yang ◽  
X. F. Meng ◽  
Y. R. Wang ◽  
Z. Huang ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Beam Splitter ◽  
Square Lattice ◽  
Beam Splitting ◽  
Splitting Ratio ◽  
Application Potential ◽  
Wave Methods ◽  
The Relationship ◽  
Optical Integration ◽  
Difference Time

This study proposes a novel beam splitter system based on graded photonic crystals, wherein the GPCs are part of a circular PC. A self-collimating PC structure with a square lattice is added to improve transmissivity. The total transmissivity is increased by extending the defect of the self-collimating PC. This study presents a beam splitter system with low energy loss and the best total transmissivity of almost 90%. Furthermore, the relationship between the beam-splitting ratio and the light position is discovered, and the beam-splitting ratio may be changed discretionarily and expediently. Numerical results are obtained using finite-difference time domain and plane wave methods. The proposed structure has significant application potential in optical integration.

Development of System for Simultaneous Measurement of Stress and Temperature

2006 ◽  
Vol 326-328 ◽  
pp. 163-166 ◽  
Author(s):  
Eisaku Umezaki ◽  
Masahito Abe
Keyword(s):  
Time Series ◽  
Simultaneous Measurement ◽  
Beam Splitter ◽  
Visible Range ◽  
Ultraviolet Rays ◽  
Infrared Range ◽  
Curing Process ◽  
Beam Splitting ◽  
Ultraviolet Curing ◽  
Phase Stepping

A system was developed for simultaneously measuring stress and temperature in structures in time series. The stress and temperature were measured using the photoelastic technique in the form of phase stepping and the thermographic technique, respectively. Four phase-stepped photoelastic images were captured simultaneously using beam-splitting optics. A beam splitter was used for transmitting light in the visible range while simultaneously reflecting light in the infrared range. The system was applied to ultraviolet curing resin with a step part illuminated with ultraviolet rays, and the stress and temperature in the curing process were measured. Results showed that the stress and temperature in the curing process can be measured simultaneously in time series using the system. The step part of the resin affected the distribution of the stress and temperature

scholarly journals Study of XUV beam splitter flatness for use on a Michelson interferometer

2004 ◽  
Vol 22 (3) ◽  
pp. 279-284 ◽  
Author(s):  
ANNE-SOPHIE MORLENS ◽  
PHILIPPE ZEITOUN ◽  
LAURENT VANBOSTAL ◽  
PASCAL MERCERE ◽  
GRÉGORY FAIVRE ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Ion Beam ◽  
Michelson Interferometer ◽  
Fourier Transform Spectrometer ◽  
Ion Beam Sputtering ◽  
X Ray ◽  
Interference Fringes ◽  
Beam Sputtering ◽  
20 Nm ◽  
Better Than

A XUV Michelson interferometer has been developed by LIXAM/CEA/LCFIO and has been tested as a Fourier-transform spectrometer for measurement of X-ray laser line shape. The observed strong deformation of the interference fringes limited the interest of such an interferometer for plasma probing. Because the fringe deformation was coming from a distortion of the beam splitter (5 × 5 mm2open aperture, about 150 nm thick), several parameters of the multilayer deposition used for the beam splitter fabrication have been recently optimized. The flatness has been improved from 80 nm rms obtained by using the ion beam sputtering technique, to 20 nm rms by using the magnetron sputtering technique. Over 3 × 3 mm2, the beam splitter has a flatness better than 4 nm rms.

Investigation on multilayer microstructure grating for three-port splitting

2016 ◽  
Vol 30 (16) ◽  
pp. 1650195
Author(s):  
Wenhao Shu ◽  
Bo Wang ◽  
Hao Pei ◽  
Hongtao Li ◽  
Li Chen ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Single Layer ◽  
Zeroth Order ◽  
First Order ◽  
Transmission Grating ◽  
Dielectric Layers ◽  
Incident Waves ◽  
Reflection Grating ◽  
Independent Property ◽  
Polarization Independent

A new structure of microstructure reflection three-port beam splitter grating is described in this paper. The grating includes two dielectric layers and a metal slab on the substrate, where incident waves are reflected into the zeroth-order and the ± first-order with polarization-independent property. With the optimized grating profile, reflection efficiencies’ ratios between the first-order and the zeroth-order can reach 0.998 and 1.001 for TE and TM polarizations, respectively. Especially, the reflection grating can diffract efficiencies more than 30% into the ± first-order and the zeroth-order with the incident angular bandwidth of −1.9–1.9[Formula: see text] for TM polarization, which can have merits compared with single-layer transmission grating.

scholarly journals Dual Polarized Dual Fed Vivaldi Antenna for Cellular Base Station Operating at 1.7–2.7 GHz

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Marko Sonkki ◽  
Sami Myllymäki ◽  
Jussi Putaala ◽  
Eero Heikkinen ◽  
Tomi Haapala ◽  
...  
Keyword(s):  
Base Station ◽  
Performance Criteria ◽  
Impedance Bandwidth ◽  
Total Efficiency ◽  
Antenna Structure ◽  
Radiating Element ◽  
Vivaldi Antenna ◽  
Dual Polarized ◽  
Vivaldi Antennas ◽  
Better Than

The paper presents a novel dual polarized dual fed Vivaldi antenna structure for 1.7–2.7 GHz cellular bands. The radiating element is designed for a base station antenna array with high antenna performance criteria. One radiating element contains two parallel dual fed Vivaldi antennas for one polarization with 65 mm separation. Both Vivaldi antennas for one polarization are excited symmetrically. This means that the amplitudes for both antennas are equal, and the phase difference is zero. The orthogonal polarization is implemented in the same way. The dual polarized dual fed Vivaldi is positioned 15 mm ahead from the reflector to improve directivity. The antenna is designed for -14 dB impedance bandwidth (1.7–2.7 GHz) with better than 25 dB isolation between the antenna ports. The measured total efficiency is better than -0.625 dB (87%) and the antenna presents a flat, approximately 8.5 dB, gain in the direction of boresight over the operating bandwidth whose characteristics promote it among the best antennas in the field. Additionally, the measured cross polarization discrimination (XPD) is between 15 and 30 dB and the 3 dB beamwidth varies between 68° and 75° depending on the studied frequency.

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