scholarly journals Ultra-broadband large-angle beam splitter based on a homogeneous metasurface at visible wavelengths

2020 ◽  
Vol 28 (21) ◽  
pp. 32226
Author(s):  
Jing Li ◽  
Han Ye ◽  
Tiesheng Wu ◽  
Yumin Liu ◽  
Zhongyuan Yu ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Large Angle ◽  
Visible Wavelengths

Theory of a compound large-angle atom beam splitter

2003 ◽  
Vol 68 (3) ◽  
Author(s):  
A. Zh. Muradyan ◽  
A. A. Poghosyan ◽  
P. R. Berman
Keyword(s):  
Beam Splitter ◽  
Large Angle ◽  
Atom Beam

Large-angle adjustable coherent atomic beam splitter by Bragg scattering

2002 ◽  
Vol 65 (4) ◽  
Author(s):  
A. E. A. Koolen ◽  
G. T. Jansen ◽  
K. F. E. M. Domen ◽  
H. C. W. Beijerinck ◽  
K. A. H. van Leeuwen
Keyword(s):  
Atomic Beam ◽  
Beam Splitter ◽  
Large Angle ◽  
Bragg Scattering

Theory of a compound large-angle atom beam splitter. II. Initial state deflection

2004 ◽  
Vol 70 (6) ◽  
Author(s):  
A. Zh. Muradyan ◽  
G. A. Muradyan ◽  
P. R. Berman
Keyword(s):  
Beam Splitter ◽  
Large Angle ◽  
Atom Beam ◽  
Initial State

scholarly journals Nanograting-Enhanced Optical Fibers for Visible and Infrared Light Collection at Large Input Angles

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 295
Author(s):  
Ning Wang ◽  
Matthias Zeisberger ◽  
Uwe Hübner ◽  
Markus A. Schmidt
Keyword(s):  
Optical Fibers ◽  
High Performance ◽  
Large Angle ◽  
Coupling Efficiency ◽  
Numerical Aperture ◽  
Infrared Light ◽  
Light Collection ◽  
High Performance Fiber ◽  
Visible Wavelengths ◽  
Quantum Technology

The efficient incoupling of light into particular fibers at large angles is essential for a multitude of applications; however, this is difficult to achieve with commonly used fibers due to low numerical aperture. Here, we demonstrate that commonly used optical fibers functionalized with arrays of metallic nanodots show substantially improved large-angle light-collection performances at multiple wavelengths. In particular, we show that at visible wavelengths, higher diffraction orders contribute significantly to the light-coupling efficiency, independent of the incident polarization, with a dominant excitation of the fundamental mode. The experimental observation is confirmed by an analytical model, which directly suggests further improvement in incoupling efficiency through the use of powerful nanostructures such as metasurface or dielectric gratings. Therefore, our concept paves the way for high-performance fiber-based optical devices and is particularly relevant within the context of endoscopic-type applications in life science and light collection within quantum technology.

Wide-Angle Behaviors of Sub-Wavelength Metal Gratings as Polarizing Beam Splitters

2013 ◽  
Vol 552 ◽  
pp. 14-20
Author(s):  
Yun Fang Li ◽  
Chang Xi Xue
Keyword(s):  
Beam Splitter ◽  
Effective Medium Theory ◽  
Extinction Ratio ◽  
Large Angle ◽  
Polarized Light ◽  
Optical Data Storage ◽  
Second Order ◽  
Optical Data ◽  
Polarizing Beam Splitter ◽  
Sub Wavelength

A second-order effective medium theory (second-order EMT) and thin film theory have been used to design a polarizing beam splitter (PBS) composed of one-dimensional sub-wavelength metal grating, considering the material of metal to be copper (Cu). It was analyzed by the finite difference time domain method for the wavelength of 1500nm. A high extinction ratio in transmission (>55.71dB) over abroad interval of angles of incidence ([-60o, 60o]) is achieved with the depth and the filling factor of the grating chosen to be 350nm and 0.3762, which are selected to transmit TM polarized light and reflect TE polarized light as much as possible at normal incident. The loss of the TE polarized light for the Cu structures is approximately less than 5.55% due to the absorption of Cu in a large angle range. The desired property will enable this type of polarizing beam splitter to be used in diverging beams. When the PBS needs to transmit approximately 25% of the TE polarized light and as much as possible the TM polarized light, it can be used in magneto-optical data storage head. But the depth of grating has been changed (approximately d=40nm) and TM transmission is only 94.7%. But it can be further improved (from 94.7% to 97.97%) by etching into the substrate.

Detection and Characterization of earth-like Planets

1997 ◽  
Vol 161 ◽  
pp. 299-311 ◽  
Author(s):  
Jean Marie Mariotti ◽  
Alain Léger ◽  
Bertrand Mennesson ◽  
Marc Ollivier
Keyword(s):  
Direct Detection ◽  
Contrast Ratio ◽  
Angular Size ◽  
Physical Nature ◽  
Major Axis ◽  
Infrared Emission ◽  
Space Technology ◽  
Semi Major Axis ◽  
Earth Like Planets ◽  
Visible Wavelengths

AbstractIndirect methods of detection of exo-planets (by radial velocity, astrometry, occultations,...) have revealed recently the first cases of exo-planets, and will in the near future expand our knowledge of these systems. They will provide statistical informations on the dynamical parameters: semi-major axis, eccentricities, inclinations,... But the physical nature of these planets will remain mostly unknown. Only for the larger ones (exo-Jupiters), an estimate of the mass will be accessible. To characterize in more details Earth-like exo-planets, direct detection (i.e., direct observation of photons from the planet) is required. This is a much more challenging observational program. The exo-planets are extremely faint with respect to their star: the contrast ratio is about 10−10at visible wavelengths. Also the angular size of the apparent orbit is small, typically 0.1 second of arc. While the first point calls for observations in the infrared (where the contrast goes up to 10−7) and with a coronograph, the latter implies using an interferometer. Several space projects combining these techniques have been recently proposed. They aim at surveying a few hundreds of nearby single solar-like stars in search for Earth-like planets, and at performing a low resolution spectroscopic analysis of their infrared emission in order to reveal the presence in the atmosphere of the planet of CO H2O and O3. The latter is a good tracer of the presence of oxygen which could be, like on our Earth, released by biological activity. Although extremely ambitious, these projects could be realized using space technology either already available or in development for others missions. They could be built and launched during the first decades on the next century.

Parallel Detection of Electron Energy Loss Spectra in Direct Mode

1990 ◽  
Vol 48 (2) ◽  
pp. 82-83
Author(s):  
Eckhard Quandt ◽  
Stephan laBarré ◽  
Andreas Hartmann ◽  
Heinz Niedrig
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Energy Resolution ◽  
Large Angle ◽  
Maximum Energy ◽  
Semiconductor Detectors ◽  
Parallel Detection ◽  
Photodiode Arrays ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Due to the development of semiconductor detectors with high spatial resolution -- e.g. charge coupled devices (CCDs) or photodiode arrays (PDAs) -- the parallel detection of electron energy loss spectra (EELS) has become an important alternative to serial registration. Using parallel detection for recording of energy spectroscopic large angle convergent beam patterns (LACBPs) special selected scattering vectors and small detection apertures lead to very low intensities. Therefore the very sensitive direct irradiation of a cooled linear PDA instead of the common combination of scintillator, fibre optic, and semiconductor has been investigated. In order to obtain a sufficient energy resolution the spectra are optionally magnified by a quadrupole-lens system.The detector used is a Hamamatsu S2304-512Q linear PDA with 512 diodes and removed quartz-glas window. The sensor size is 13 μm ∗ 2.5 mm with an element spacing of 25 μm. Along with the dispersion of 3.5 μm/eV at 40 keV the maximum energy resolution is limited to about 7 eV, so that a magnification system should be attached for experiments requiring a better resolution.

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