Results 41 to 50 of about 3,906 (246)

Space‐Time Coding Conformal Metasurfaces for Multifrequency Beam Steering and Shaping

Advanced Materials, EarlyView.
Space‐time coding conformal metasurfaces enable dynamic wave control on curved surfaces by combining programmable spatial patterns with temporal modulation. This study shows that a single conformal aperture can independently manipulate multiple frequency components, achieving multifunctional beam shaping and steering, with implications for ...
Filippo Pepe, Lei Zhang, Yi Ning Zheng, Xiao Qing Chen, Ivan Iudice, Giuseppe Castaldi, Marco Di Renzo, Tie Jun Cui, Vincenzo Galdi   +8 more
wiley   +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

Compressive wavefront sensing with weak values

Optics Express, 2014
We demonstrate a wavefront sensor based on the compressive sensing, single-pixel camera. Using a high-resolution spatial light modulator (SLM) as a variable waveplate, we weakly couple an optical field's transverse-position and polarization degrees of freedom.
Howland, Gregory A., Lum, Daniel J., Howell, John C.   +2 more
openaire   +4 more sources

Coating‐Free Nanoscratching for Liquid‐Crystal Alignment on PCB‐Compatible Millimeter‐Wave Reflective Unit Cells

Advanced Materials Technologies, EarlyView.
Direct nanoscratching with a 500 nm diamond lapping film creates groove‐guided liquid‐crystal alignment interfaces on PCB‐compatible Cu‐patterned RF substrates within minutes, eliminating polymer coating and high‐temperature baking. The coating‐free process enables optical/molecular alignment validation and voltage‐programmable 28 GHz reflection‐phase ...
Junseok Ma, Ga‐Yeong Park, Geunjung Lee, Hyo‐Won Lee, Jong‐Won Yu, Dong Ki Yoon   +5 more
wiley   +1 more source

Wood‐Derived Nanocellulose‐Biocarbon Fresnel‐Zone Plate Lenses for Sub‐THz Frequency Applications

Advanced Materials Technologies, EarlyView.
Wood‐derived nanocellulose and lignin‐based biocarbon were combined to fabricate fully bio‐based Fresnel zone plate (FZP) lenses for sub‐terahertz frequencies. These sustainable FZP lenses exhibit low dielectric loss and high directivity, achieving performance comparable to that of metallic references, and remain functional under environmental stress ...
Riikka Haataja, Mikko Kokkonen, Niina Halonen, Sami Myllymäki, Umair Rafique, Mandeep Singh, Ossi Laitinen, Heli Jantunen, Kristiina Oksman, Henrikki Liimatainen   +9 more
wiley   +1 more source

In Situ Two‐Dimensional Residual Stress Characterization of Thin Films

Advanced Materials Technologies, EarlyView.
An integrated in situ curvature metrology platform combining speckle‐based curvature optical metrology (SCOM) with multi‐beam optical sensors (MOS) enables spatially resolved two‐dimensional curvature mapping of thick sputtered coatings. The SCOM technique provides excellent agreement with MOS while providing an extended measurable curvature range ...
Wai Jue Tan, Wadwan Singhapong, Arindam Majhi, Chris Bowen, Alexander J.G. Lunt, Hongchang Wang, Kawal Sawhney   +6 more
wiley   +1 more source

Improved Phase Diversity Wavefront Sensing with a Deep Learning-Driven Hybrid Optimization Approach

Photonics
Phase diversity wavefront sensing (PDWS) is a model-based wavefront estimation technique that avoids additional optical components, making it suitable for resource-constrained environments.
Yangchen Wang, Ming Wen, Hongcai Ma
doaj   +1 more source

Accounting for Polychromatic Light in Virtual Shack-Hartmann Wavefront Sensing

Photonic Sensors, 2023
Virtual Shack-Hartmann wavefront sensing (vSHWS) has some significant advantages and is promising for aberration measurement in the field of biomedical optical imaging.
Xian Yue, Yaliang Yang, Hao Dai, Shen Chen, Chao Geng, Yudong Zhang   +5 more
doaj   +1 more source

Full‐Stokes Polarimetry Metasurface‐Enabled Single‐Shot Measurement of the Spin Hall Effect of Light

Advanced Optical Materials, EarlyView.
This study presents a metasurface‐enabled approach to measure the spin Hall effect of light in a single‐shot. The metasurface splits a reflected light into six polarization‐dependent focal spots, allowing all Stokes parameters to be obtained from single image.
Jeonghoon Choi, Jaekyung Kim, Sujeong Park, Doyoon Lee, Juhoon Baek, Junsuk Rho, Minkyung Kim   +6 more
wiley   +1 more source

Wavefront sensing reveals optical coherence [PDF]

Nature Communications, 2014
Wavefront sensing is a set of techniques providing efficient means to ascertain the shape of an optical wavefront or its deviation from an ideal reference. Due to its wide dynamical range and high optical efficiency, the Shack-Hartmann is nowadays the most widely used of these sensors.
Stoklasa, B., Motka, L., Rehacek, J., Hradil, Z., Sanchez-Soto, L. L.   +4 more
openaire   +3 more sources