Results 111 to 120 of about 61,321 (227)

Analytical formula of Free Electron Laser exponential gain for non-resonant electron beam

, 2014
The FEL gain formulas for non-resonant case are studied. For the mono-energetic and non-resonant electron beam, the exact expression of the solution of the FEL characteristic cubic equation is obtained with a form much more simple than that in the ...
Jia, Qika
core   +1 more source

A tunable microwave absorption metamaterial inspired by moths evading bat detection

InfoMat, EarlyView.
Electromagnetic radiation in the current environment has become complex and uncontrollable due to the advancement of wireless technology. Inspired by the moth surface cilia to bend and evade bat sonar detection, our work introduces a metamaterial incorporating broadband and tunable microwave absorption properties combined with deep learning algorithms.
Yijie Liu, Weimeng Chu, Jintang Zhou, Zhenyu Cheng, Yi Yan, Yuanming Yang, Ruiyang Tan, Shiju Liu, Ping Chen, Yucheng Wang, Lvtong Duan, Yao Ma, Xiangshuai Song, Zhengjun Yao   +13 more
wiley   +1 more source

Increasing the measurable frequency range of magnetic field oscillations with off-resonance spin-lock preparation pulses. [PDF]

Magn Reson Med
Abstract Purpose Oscillatory magnetic fields—arising from, e.g., neuronal currents or induced currents during brain stimulation—can be measured with spin‐lock preparation pulses, where the frequency of the measured field matches the amplitude of the spin‐lock pulse.
Gregersen F, Cunha T, Thielscher A, Hanson LG.   +3 more
europepmc   +2 more sources

Photo‐Excitations in Halide Perovskites: Where Do Simulations and Experiments Meet?

Laser &Photonics Reviews, EarlyView.
Aiming to bridge the gap between simulations and measurements of light–matter couplings and photo‐excitations in new functional materials, this perspective highlights insights and bottlenecks of state‐of‐the‐art experimental and theoretical methods (2D electronic spectroscopy vs.
Muhammad Sufyan Ramzan, Antonietta De Sio, Alexander Steinhoff, Frank Jahnke, Christoph Lienau, Caterina Cocchi   +5 more
wiley   +1 more source

Comparison of Two Two-Photon Dressed Rules in Multi-Wave Mixing

IEEE Photonics Journal, 2014
For the first time, we report a novel two-photon dressed rule in a five-level $^{85}\hbox{Rb}$ atomic system. In comparison with a traditional two-photon dressed rule where the signals move with probe field frequency detuning changing, the novel one ...
Jia Sun, Peiying Li, Gaoping Huang, Yunzhe Zhang, Dan Zhang, Hao Tian, Heqing Huang, Yanpeng Zhang   +7 more
doaj   +1 more source

Detuning effects in parametric amplifiers

Electronics Letters, 1965
Some detuning effects in parametric amplifiers have been observed when the pump frequency is above and below the optimum value. A possible explanation of these effects is suggested.
K.L. Hughes, B.S. Lee, D. Lynes, J.D. Pearson   +3 more
openaire   +1 more source

Engineering Topological Phases with a Traveling‐Wave Spacetime Modulation

Laser &Photonics Reviews, EarlyView.
Time‐varying systems have garnered considerable attention due to their unique potential in manipulating electromagnetic waves. Here, a novel class of topological spacetime crystals with a traveling‐wave modulation is introduced. By manipulating material anisotropy, one can engineer light angular momentum and non‐trivial topological phases characterized
João C. Serra, Mário G. Silveirinha
wiley   +1 more source

Enhancement and Speed‐Up of Carrier Dynamics in A Dielectric Nanocavity with Deep Sub‐Wavelength Confinement

Laser &Photonics Reviews, EarlyView.
This work presents the first experimental investigation of ultrafast dynamics in dielectric bowtie nanocavities, featuring deep‐subwavelength mode confinement. Measurements reveal enhanced two‐photon absorption, sub‐picosecond carrier relaxation, and strong pump–probe interactions, demonstrating clear advantages over conventional nanocavities for low ...
Gaoneng Dong, Ali Nawaz Babar, Rasmus Ellebæk Christiansen, Søren Engelberth Hansen, Søren Stobbe, Yi Yu, Jesper Mørk   +6 more
wiley   +1 more source

Efficient Robust Spontaneous Parametric Down‐Conversion via Detuning Modulated Composite Segments Designs

Laser &Photonics Reviews, EarlyView.
Detuning modulated composite segmentation (DMCS) enables robust spontaneous parametric down‐conversion with sevenfold improved temperature stability compared to conventional designs, opening new possibilities for stable quantum photon sources. ABSTRACT Spontaneous parametric down conversion (SPDC) holds a pivotal role in quantum physics, facilitating ...
Muhammad Erew, Yuval Reches, Ofir Yesharim, Moshe Goldstein, Ady Arie, Haim Suchowski   +5 more
wiley   +1 more source

Pulsed Quantum Excitation

Laser &Photonics Reviews, EarlyView.
This manuscript demonstrates the improvements that single photon sources can gain if their source of excitation is quantum rather than classical. Illuminating a pair of identical two‐level systems, the author shows that the excitation with pulses of quantum light yields more antibunched and more indistinguishable emission than if the excitation were ...
Juan Camilo López Carreño
wiley   +1 more source