Results 231 to 240 of about 655,925 (308)

High efficiency acoustic Fresnel lens

Journal of Physics D: Applied Physics, 2019
We present a water-immersed ultrasound high-efficiency Fresnel lens based on the theory of extraordinary acoustic transmission of plate-wave resonance.
Qinxin Zhou, Zheng Xu, Xiao-jun Liu
semanticscholar   +2 more sources

Backlight system using an interleaved Fresnel lens array that attains a uniform luminance and two-dimensional directional light control.

Optics Letters, 2021
A novel (to the best of our knowledge) Fresnel lens array is proposed to realize a uniform directional backlight with two-dimensional directionality. Autostereoscopic display with the proposed lens array improves image output quality and relieves the ...
Garimagai Borjigin, H. Kakeya
semanticscholar   +1 more source

Seven-Rod Pumping Approach for the Most Efficient Production of TEM00 Mode Solar Laser Power by a Fresnel Lens

, 2021
A seven-rod/seven-TEM00 mode beam Fresnel lens solar laser pumping approach is here proposed. The Fresnel lens with 4.0 m2 collection area was used as the primary solar concentrator to pump seven 2.5 mm diameter, 15 mm length Nd:YAG rods within a ...
D. Liang, J. Almeida, B. Tibúrcio, M. Catela, D. Garcia, H. Costa, C. Vistas   +6 more
semanticscholar   +1 more source

Reconfigurable Fresnel Lens Based on an Active Second-Order Bandpass Frequency-Selective Surface

IEEE Transactions on Antennas and Propagation, 2020
In this communication, we experimentally demonstrate a frequency- and beam-reconfigurable lens antenna based on an active second-order bandpass frequency-selective surface (FSS).
Huan Li, Chao Ma, Tianyi Zhou, Jun Wang, Dexin Ye, Yongzhi Sun, Weiqiang Zhu, T. Denidni, L. Ran   +8 more
semanticscholar   +1 more source

A Reconfigurable Planar Fresnel Lens for Millimeter-Wave 5G Frontends

IEEE transactions on microwave theory and techniques, 2020
Besides the prohibitive cost, complexity, and baseband scale, the development of millimeter-wave (mmWave) digital-beamforming fifth-generation (5G) frontends is facing a physical-layer challenge of thermal dissipation.
Qiangli Xi, Chao Ma, Huan Li, Bin Zhang, Changzhi Li, L. Ran   +5 more
semanticscholar   +1 more source

Linear Fresnel lens concentrators

Solar Energy, 1975
Abstract The use of the linear Fresnel lens as a seasonally adjusted or one-axis tracked solar concentrator is investigated. Ray tracing techniques are used to show that this type of concentrator is very good in the period of time within 1 hr of solar noon.
D.T. Nelson, D.L. Evans, R.K. Bansal
openaire   +1 more source

3-D Printed Circularly Polarized Modified Fresnel Lens Operating at Terahertz Frequencies

IEEE Transactions on Antennas and Propagation, 2019
In this paper, a novel 3-D printed circularly polarized (CP) modified Fresnel lens antenna operating at 300 GHz is introduced. By virtue of the superior geometric flexibility of the 3-D printing technique, a modified Fresnel lens consisting of ...
Gengbo Wu, Yuan-Song Zeng, K. Chan, Shiwei Qu, C. Chan   +4 more
semanticscholar   +1 more source

Experimental investigation of a box-type solar cooker incorporated with Fresnel lens magnifier

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
The study was conducted to evaluate the thermal performance of a box-type solar cooker (BTSC) by implementing two Fresnel lens magnifiers (FLMG) which concentrate the solar irradiance on to the cooker surface. A comparison in thermal performance was done
Gulsavin Guruprasad Engoor, S. Shanmugam, A. Veerappan   +2 more
semanticscholar   +1 more source

A “tuned” Fresnel lens

Applied Optics, 1986
We propose a technique to manufacture Fresnel lenses where the grooves are phase-synchronized at a given wavelength. This means that the light from different grooves will superpose coherently at the focal point at the specified wavelength. The focusing performance of such a “tuned” Fresnel lens will be better than that of ordinary Fresnel lenses by ...
openaire   +2 more sources

Three-zone multifocus hybrid Fresnel lens concentrator

Applied Optics, 2021
In this paper, we designed a three-zone multifocus hybrid Fresnel lens concentrator without a homogenizer. This concentrator uses three types of prisms: a refractive prism, a single total internal reflection (STIR) prism, and a double TIR (DTIR) prism.
Ya-Chi, Lu, Jui-Wen, Pan
openaire   +2 more sources