scholarly journals Graphene-based electrically controlled terahertz polarization switching between a quarter-wave plate and half-wave plate

2020 ◽  
Vol 28 (26) ◽  
pp. 39430
Author(s):  
XiangQian Qi ◽  
JingLan Zou ◽  
Chao Li ◽  
JianFa Zhang ◽  
ChuCai Guo ◽  
...  
Keyword(s):  
Polarization Switching ◽  
Quarter Wave Plate ◽  
Half Wave Plate ◽  
Wave Plate ◽  
Half Wave ◽  
Quarter Wave

scholarly journals Switchable Quarter-Wave Plate and Half-Wave Plate Based on Phase-Change Metasurface

2020 ◽  
Vol 12 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Yaru Li ◽  
Jun Luo ◽  
Xiong Li ◽  
Mingbo Pu ◽  
Xiaoliang Ma ◽  
...  
Keyword(s):  
Phase Change ◽  
Quarter Wave Plate ◽  
Half Wave Plate ◽  
Wave Plate ◽  
Half Wave ◽  
Quarter Wave

scholarly journals Transmission Control of Electromagnetic Waves by Using Quarter-Wave Plate and Half-Wave Plate All-Dielectric Metasurfaces Based on Elliptic Dielectric Resonators

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Yahyaoui ◽  
Hatem Rmili ◽  
Karim Achouri ◽  
Muntasir Sheikh ◽  
Abdullah Dobaie ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Electromagnetic Waves ◽  
Quarter Wave Plate ◽  
Dielectric Resonators ◽  
Transmission Control ◽  
Half Wave Plate ◽  
Wave Plate ◽  
Polarized Waves ◽  
Half Wave ◽  
Quarter Wave

We present the design of all-dielectric Quarter-Wave Plate (QWP) and Half-Wave Plate (HWP) metasurfaces based on elliptic dielectric resonators (EDRs) for the transmission control of electromagnetic waves over the frequency band 20–30 GHz. First, an extensive numerical analysis was realized by studying the effect of the resonators geometry (thickness and ellipticity) on the transmission of both x- and y-polarized waves. Then, based on the numerical analysis, we have realized and characterized experimentally both QWP and HWP all-dielectric metasurfaces.

Passband-Flattened Frequency-Tunable Optical Fiber Multiwavelength Filter with Composite Combination of Waveplates

2021 ◽  
Vol 21 (8) ◽  
pp. 4200-4207
Author(s):  
Jaehoon Jung ◽  
Yong Wook Lee
Keyword(s):  
Beam Splitter ◽  
Orientation Angle ◽  
Quarter Wave Plate ◽  
Half Wave Plate ◽  
Wave Plate ◽  
Half Wave ◽  
Quarter Wave ◽  
Polarization Maintaining Fiber ◽  
Polarization Maintaining ◽  
Frequency Tunable

We propose a passband-flattened frequency-tunable optical multiwavelength filter with a composite combination of waveplates, which is realized by harnessing a polarization-diversified loop structure. The proposed filter comprises a polarization beam splitter (PBS), two polarization-maintaining fiber (PMF) segments of equal length, an ordered waveplate combination (OWC) of a half-wave plate (HWP) and a quarter-wave plate (QWP) before the first PMF segment, and an OWC of a QWP and an HWP before the second PMF segment. The second PMF segment is butt-coupled to one port of the PBS so that its slow axis is oriented at 22.5° for the horizontal axis of the PBS. Based on the filter transmittance derived through the Jones calculus, we found the orientation angle (OA) sets of the four waveplates, which could induce an extra phase shift Φ from 0° to 360° in the passband-flattened transmittance function. From the transmission spectra calculated at the eight selected OA sets, which caused Φ to increase from 0° to 315° by steps of 45°, it was confirmed that the passband-flattened multiwavelength spectrum can be continuously tuned by properly controlling the OAs. This indicates continuous wavelength tunability based on composite OWCs. Then, this theoretical prediction was verified by experimental demonstration.

Application of Laser Doppler Technique in Measurement of Explosive Container Based on Frequency Correction

2013 ◽  
Vol 391 ◽  
pp. 497-500
Author(s):  
Hong Li Liu ◽  
Lei Shao ◽  
Hai Bin Zuo ◽  
Nan Liu
Keyword(s):  
Processing Speed ◽  
Beam Splitter ◽  
Correction Method ◽  
Laser Doppler ◽  
Quarter Wave Plate ◽  
Wave Plate ◽  
Half Wave ◽  
Frequency Correction ◽  
Quarter Wave ◽  
Short Time

Dynamic measurement of explosion containment vessel deformation for explosive experiment is obtained using laser doppler effect. The system is based on optical heterodyning technologies, and uses half wave plate, quarter wave plate, polarization beam splitter and acousto-optic modulator to improve the intensity of doppler signal and signal-noise-ratio. Short time fourier transform and energy centrobaric correction method using hamming window is applied to improve the signal processing speed and the accuracy. The experimental results of explosive container are presented under 20g TNT explosion.

scholarly journals A full-Stokes polarimeter for the GREGOR Fabry-Perot interferometer

2008 ◽  
Vol 4 (S259) ◽  
pp. 665-666 ◽  
Author(s):  
Horst Balthasar ◽  
N. Bello González ◽  
M. Collados ◽  
C. Denker ◽  
A. Hofmann ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Beam Splitter ◽  
Quarter Wave Plate ◽  
Ferroelectric Liquid Crystals ◽  
Wave Plate ◽  
Half Wave ◽  
Fabry Perot ◽  
Quarter Wave ◽  
Optimum Wavelength ◽  
High Cadence

AbstractOne of the first post-focus instruments of the new solar telescope GREGOR will be a Fabry-Perot spectrometer, which is an upgrade of the Göttingen Fabry-Perot interferometer at the Vacuum Tower Telescope (VTT) on Tenerife. This spectrometer is equipped with a full-Stokes polarimeter. The modulation is performed with two ferroelectric liquid crystals, one acting nominally as quarter-wave plate, and the other as half-wave plate. A modified Savart plate serves as polarimetric beam splitter. With the present liquid crystals, the optimum wavelength range of this polarimeter is between 580 and 660 nm. The spectro-polarimeter will benefit from the capabilities of the new telescope GREGOR which will provide a spatial resolution of about 0″.1 (75 km on the solar surface). Thus we will be able to investigate small magnetic features, and we will study their development with high cadence.

scholarly journals Arbitrary Phase Modulation of General Transmittance Function of First-Order Optical Comb Filter with Ordered Sets of Quarter- and Half-Wave Plates

2020 ◽  
Vol 10 (16) ◽  
pp. 5434
Author(s):  
Jaehoon Jung ◽  
Yong Wook Lee
Keyword(s):  
Phase Modulation ◽  
Comb Filter ◽  
Quarter Wave Plate ◽  
First Order ◽  
Wave Plate ◽  
Half Wave ◽  
Arbitrary Phase ◽  
Quarter Wave ◽  
Polarization Maintaining Fiber ◽  
Optical Comb Filter

Here we theoretically and experimentally demonstrated the arbitrary phase modulation of a general transmittance function (GTF) of the first-order optical comb filter based on a polarization-diversity loop structure, which employed two ordered waveplate sets (OWS’s) of a quarter-wave plate (QWP) and a half-wave plate (HWP). The proposed comb filter is composed of a polarization beam splitter (PBS), two equal-length polarization-maintaining fiber (PMF) segments, and two OWS’s of a QWP and an HWP with each set located before each PMF segment. The second PMF segment is butt-coupled to one port of the PBS so that its principal axis should be 22.5° away from the horizontal axis of the PBS. First, we explained a scheme to find four waveplate orientation angles (WOA’s) allowing the phase of a GTF to be arbitrarily modulated, using the way each component of the filter, such as a waveplate or PMF segment, affects its input or output polarization. Then, with the WOA finding method, we derived WOA sets of the four waveplates, which could give arbitrary phase retardations ϕ’s from 0° to 360° to a GTF chosen here arbitrarily. Finally, we showed phase-modulated GTF’s calculated at eight selected WOA sets allowing ϕ’s to be 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°, and then the predicted results were verified by experimentally measured results. It is concluded from the theoretical and experimental demonstrations that the GTF of our filter based on the OWS of a QWP and an HWP can be arbitrarily phase-modulated by properly controlling the WOA’s of the four waveplates.

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