Results 61 to 70 of about 1,039,039 (252)

On‐Chip Photonic Neural Network Architectures

Advanced Optical Materials, EarlyView.
This review presents a comprehensive overview of on‐chip photonic neural network architectures, covering key photonic building blocks, representative network types, and emerging applications. Recent advances, implementation challenges, and future directions are examined, highlighting the potential of integrated photonics to enable ultrafast, energy ...
Seokjin Hong, Berkay Neseli, Seungyeon Cho, Seungsoo Lee, Yeonjun Kim, Seungyoon Choi, Hyo‐Hoon Park, Hamza Kurt   +7 more
wiley   +1 more source

Wavefront Sensor [PDF]

, 2016
Wavefront reconstruction techniques have enabled important scientific improvements to corrective imaging in astronomy, optometry, and elsewhere. Here, we describe the design of a wavefront reconstruction-based adaptive optics system designed at Santa ...
Mulé, Richard
core   +1 more source

Photonic integrated circuits for astronomy: A formal description of an integrated photonics-based wavefront sensor (IP-WFS)

Astronomy & Astrophysics
Context. Solar wavefront sensing has been a challenge for astrophysical instrumentalists, due to the low contrast between the Sun and the sky background compared to night-time observations, which limits the performance of adaptive optics systems.
Portero-Rodríguez D., García-Vázquez H., Díaz García J. J., Rodríguez Ramos L. F., Gracia Témich F., Aguerri J. Alfonso L.   +5 more
doaj   +1 more source

Large‐Area Flat Optics Color Routing in Tilted Arrays of 2D Semiconductor Nanostripes

Advanced Optical Materials, EarlyView.
We develop a scalable flat optics platform exploiting self‐organised ion‐beam sputtering and maskless glancing‐angle deposition to fabricate centimetre‐scale arrays of tilted MoS2 nanostripes. The engineered geometry activates Rayleigh anomalies, guided modes, and Mie resonances, enabling highly directional color routing and enhanced light harvesting ...
Simone Di Marco, Daniele Ceneda, Matteo Barelli, Matteo Gardella, Rajesh Chennuboina, Maria C. Giordano, Marco Centini, Francesco Buatier de Mongeot   +7 more
wiley   +1 more source

Turning Light Into Matter: Programmable Microstructures Via Dose Control in Two‐Photon Polymerization

Advanced Optical Materials, EarlyView.
This work augments two‐photon polymerization with point‐wise dose control, enabling structures with heterogeneous material properties such as refractive index. An open source toolbox and superior calibration methodology for the refractive index pave the way for bio‐mimicking or numerically optimized structure designs, and enhance the synergy between 3D
Michał Ziemczonok, Koen Vanmol
wiley   +1 more source

Adaptive particle image velocimetry based on sharpness metrics

Journal of the European Optical Society-Rapid Publications, 2018
Background Optical distortions can significantly deteriorate the measurement accuracy in particle image velocimetry systems. Such distortions can occur at fluctuating phase boundaries during flow measurement and result from the accompanied refractive ...
M. Teich, J. Grottke, H. Radner, L. Büttner, J. W. Czarske   +4 more
doaj   +1 more source

Using the generalised-optical differentiation wavefront sensor for laser guide star wavefront sensing [PDF]

, 2020
Laser guide stars (LGS) are used in many adaptive optics systems to extend sky coverage. The most common wavefront sensor used in combination with a LGS is a Shack-Hartmann wavefront sensor (SHWFS). The ShackHartmann has a major disadvantage for extended
Dekany, Richard G., Haffert, S.Y., Keller, Christoph U., Keller, C.U., Haffert, Sebastiaan Y., Dekany, R., Dekany, Richard   +6 more
core   +1 more source

Wavelength‐Multiplexed 2D Beam Steering via a Passive Diffractive Network

Advanced Optical Materials, EarlyView.
Illustration of a wavelength‐multiplexed diffractive beam steering system, which is composed of K cascaded diffractive layers, each containing phase‐modulating elements that are jointly optimized using deep learning–based optimization. When illuminated with a set of wavelengths {λ1,λ2,…,λNw}$\{ {{{\lambda }_1},{{\lambda }_2},\ldots ,{{\lambda }_{{{N}_w}
Che‐Yung Shen, Yuhang Li, Çağatay Işıl, Tianyi Gan, Mona Jarrahi, Aydogan Ozcan   +5 more
wiley   +1 more source

Terahertz wavefront measurement with a Hartmann sensor

, 2012
The measurement of the wavefront of a terahertz (THz) beam is essential for the development of any optical instrument operating at THz frequencies. We have realized a Hartmann wavefront sensor for the THz frequency range.
Grahn, Holger-T., H. Richter, Pfund, Johannes, Hey, Robert, M. Greiner-Bär, Wienold, Martin, Greiner-Bär, Michael, J. Pfund, Deßmann, Nils, Richter, Heiko, Schrottke, Lutz, Hübers, Heinz-Wilhelm, H.-W. Hübers, M. Wienold, L. Schrottke, H. T. Grahn, R. Hey, N. Deßmann   +17 more
core   +1 more source

Coherent Absorption Reveals Colors Hidden in a Grey Fabry–Pérot Cavity

Advanced Optical Materials, EarlyView.
A dielectric thin film shows colors depending on its thickness; this effect can be used to encode information normally accessible through single‐beam spectroscopy. We developed a method to conceal this kind of information, based on coating the dielectric with a matched conductor, that suppresses the color‐bearing thin‐film resonances.
Giuseppe E. Lio, Giulio Carotta, Lorenzo Lavista, Andrea Camposeo, Giacomo Venturi, Agnese Guernieri, Alessandro Pitanti, Simon A. R. Horsley, Giuseppe C. La Rocca, Alessandro Tredicucci, Simone Zanotto   +10 more
wiley   +1 more source