In this paper, we will review both past and recent progresses in the generation, detection and application of intense terahertz (THz) radiation. We will restrict the review to laser based intense few-cycle THz sources, and thus will not include sources such as synchrotron-based or narrowband sources. We will first review the various methods used for generating intense THz radiation, including photoconductive antennas (PCAs), optical rectification sources (especially the tilted-pulse-front lithium niobate source and the DAST source, but also those using other crystals), air plasma THz sources and relativistic laser–plasma sources. Next, we will give a brief introduction on the common methods for coherent THz detection techniques (namely the PCA technique and the electro-optic sampling), and point out the limitations of these techniques for measuring intense THz radiation. We will then review three techniques that are highly suited for detecting intense THz radiation, namely the air breakdown coherent detection technique, various single-shot THz detection techniques, and the spectral-domain interferometry technique. Finally, we will give an overview of the various applications that have been made possible with such intense THz sources, including nonlinear THz spectroscopy of condensed matter (optical-pump/THz-probe, THz-pump/THz-probe, THz-pump/optical-probe), nonlinear THz optics, resonant and non-resonant control of material (such as switching of superconductivity, magnetic and polarization switching) and controlling the nonlinear response of metamaterials. We will also provide a short perspective on the future of intense THz sources and their applications.
This paper compares ferrite and amorphous sheets as shielding materials for NFC tag antennas on metal surfaces. The presence of metal surface poses challenges to NFC communication, impacting the reading of the tag. Effective shielding materials are necessary to mitigate these challenges. Experimental evaluations are conducted to assess the performance of the NFC tag antenna in terms of signal strength, inductance, and reading range in the presence of ferrite and amorphous materials. The results demonstrate significant enhancements in signal strength when utilizing ferrite material compared to amorphous material. However, amorphous materials offer the advantage of lower thickness, enabling broader application possibilities.
Abstract Ground track response analysis is an alternative method utilized to investigate the influence of ground-borne vibrations induced by speed train on track. This study intended to get an understanding about the responsive of ground towards vibration induced from moving train. To facilitate this study, non-destructive seismic wave method was performed using new application, Sirius M instrument to identify the peak vertical acceleration generated at various running speed and track locations. The result shows the vertical acceleration data signalized from transition wave generate through passing Electric Train Service (ETS) with maximum 140km.hr −1 speed train is higher than commuter with 120km.hr −1 speed train which are 1.935m.s −2 and 1.051m.s −2 respectively. Analysis of vertical acceleration data based on different track locations corresponding to the ETS speed resulting higher peak acceleration at stable track, KM21 compared to settlement susceptible track, KM20.75 which are 6.565m.s −2 and 1.935m.s −2 respectively. The values obtained from this study indicated ground-borne vibration influenced by speed of train and different type of embankment foundation. This data can be used to assess the influences of train type and speed. Moreover, this on-site ground response measurement is potentially useful as an alternative method to determine the soil stiffness which provide an indication to the possible problematic ground susceptible to the settlement.
Quantum-statistical properties of light propagating in a coupler with third order nonlinearity are investigated. The stochastic equations describing the dynamics of the system are derived in positive-P and Wigner representations. The possibility to generate quadrature-squeezed states is shown numerically.
Certain solid solutions of perovskite-type ferroelectrics show excellent properties such as giant dielectric response and high electromechanical coupling constant in the vicinity of the morphotropic phase boundary (MPB).These materials are of importance to applications such as electrostrictive actuators and sensors, because of the large dielectric and piezoelectric constants (Jaffe et al., 1971;Sawaguchi, 1953;Kuwata et al., 1982;Newnham, 1997).The term "morphotropic" was originally used to refer to refer to phase transitions due to changes in composition (Ahart et al., 2008).Nowadays, the term 'morphotropic phase boundaries' (MPB) is used to refer to the phase transition between the tetragonal and the rhombohedral ferroelectric phases as a result of varying the composition or as a result of mechanical pressure (Jaffe et al.,
The paper outline development and simulation of Pulse Interval Encoding (PIE) encoder architecture for Ultra High Frequency (UHF) Radio Frequency Identification (RFID) reader based on Field Programmable Gate Array (FPGA). The PIE encoder architecture presented in this paper is according to International Organization for Standardization and International Electrotechnical Commission (ISO/IEC 18000-6) protocol. The behavior of the PIE encoder architecture is realized by derivation of Verilog Hardware Description Language (HDL) code in Quartus II software. Utilizing the ModelSim-Altera, the PIE encoder architecture is simulated to observe its functionality. The designing of the encoder is intended for uses in UHF RFID passive interrogator.
Abstract In this work, we have examined the generation of squeezed states of light in a two-waveguide coupler in which Raman processes are active in one waveguide. Both waveguides are mutually linearly interacting through the field’s evanescent waves. We looked at a few interesting cases in which the system generated single mode squeezed states due to spontaneous and stimulated Raman processes. Under specific combinations of design parameters and phase mismatching conditions, squeezed states may take the form of collapses and revivals, or the second quadrature of the optical mode may oscillate completely below the short-noise limit of a coherent state.
We report temperature dependence and thermal hysteresis behavior of terahertz transmission through photoexcited graphene. We vary the temperature between room temperature and 180° C, and use the optical-pump/terahertz-probe differential transmission technique.
'/%3e%3cuse xlink:href='%23a' transform='translate(0 -400)'/%3e%3cuse xlink:href='%23a' transform='translate(0 -600)'/%3e%3cuse xlink:href='%23a' transform='translate(0 -800)'/%3e%3cuse xlink:href='%23a' transform='translate(0 -1000)'/%3e%3cuse xlink:href='%23a' transform='translate(0 -1200)'/%3e%3cpath d='M0 0h1400v800H0z' style='fill:%23010066'/%3e%3cpath d='M576 100c-166.146 0-301 134.406-301 300s134.854 300 301 300c60.027 0 115.955-17.564 162.927-47.783-27.353 9.44-56.71 14.602-87.271 14.602-147.327 0-266.897-119.172-266.897-266.01 0-146.837 119.57-266.01 266.897-266.01 32.558 0 63.746 5.815 92.602 16.468C696.217 118.91 638.305 100 576 100z' style='fill:%23fc0'/%3e%3cpath d='m914.286 471.429-99.538-53.25 29.43 108.982-66.575-91.165-20.77 110.96-20.428-111.024-66.857 90.96L699.314 418l-99.701 52.943 74.065-85.192-112.8 4.441 103.694-44.62-103.555-44.94L673.8 305.42 600 220l99.538 53.25-29.43-108.982 66.575 91.165 20.77-110.96 20.428 111.023 66.857-90.959L814.97 273.43l99.702-52.944-74.065 85.193 112.8-4.441-103.694 44.62 103.555 44.94-112.785-4.79z' style='fill:%23fc0' transform='matrix(1.2738 0 0 1.2423 -89.443 -29.478)'/%3e%3c/svg%3e)
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)