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We have shown the opportunity to use the unique inhomogeneities of the internal structure of an optical fiber waveguide for remote authentication of users or an optic fiber line. Optical time domain reflectometry (OTDR) is demonstrated to…

We describe a fiber Raman amplifier for nanosecond and sub-nanosecond pulses centered around 1260 nm. The amplification takes place inside a 4.5-m-long polarization-maintaining phosphorus-doped fiber, pumped at 1080 nm by 3-ns-long pulses…

Negative refraction has attracted much interest for its promising capability in imaging applications. Such an effect can be implemented by negative index meta-materials, however, which are usually accompanied by high loss and demanding…

Optics · Physics 2016-05-25 Jianjun Cao , Dongyi Shen , Yaming Feng , Wenjie Wan

Affine frequency division multiplexing (AFDM) has recently emerged as a promising waveform for doubly-selective channles [1],[2], owing to its ability to fully exploit time-frequency diversity through appropriate tuning of the chirp-rate…

Signal Processing · Electrical Eng. & Systems 2026-05-19 Haojian Zhang , Jiayan Yang , Tingting Zhang , Xu Zhu , Qinyu Zhang

We demonstrate a new regime for mid-infrared optical parametric chirped pulse amplification (OPCPA) based on achromatic quasi-phase-matching. Our mid-infrared OPCPA system is based on collinear aperiodically poled lithium niobate (APPLN)…

An innovative millimeter wave diagnostic is proposed to measure the local magnetic field and edge current as a function of the minor radius in the tokamak pedestal region. The idea is to identify the direction of minimum reflectivity at the…

Plasma Physics · Physics 2016-09-21 O. Meneghini , F. A. Volpe

High-energy, few-cycle laser pulses are essential for numerous applications in the fields of ultrafast optics and strong-field physics, due to their ultrafast temporal resolution and high peak intensity. In this work, different from the…

In Orthogonal Time Frequency Space (OTFS) modulation, information symbols are embedded in the delay-Doppler (DD) domain instead of the time-frequency (TF) domain. n order to ensure compatibility with existing OFDM systems (e.g. 4G LTE),…

Information Theory · Computer Science 2024-10-30 Saif Khan Mohammed

The near-field diffraction of fs and sub-fs light pulses by nm-size slit-type apertures and its implication for near-field scanning optical microscopy (NSOM) is analyzed. The amplitude distributions of the diffracted wave-packets having the…

Optics · Physics 2013-10-11 S. V. Kukhlevsky , M. Mechler , L. Csapo

Path-length diversity methods may be used for adaptive optics (AO) systems to retrieve phase and amplitude information by measuring intensity across multiple planes. Observations that rely on free-space propagation, such as the nonlinear…

Optical transition radiation interferometry (OTRI) has been shown to be a very useful technique to measure the divergence of electron beams with energies in the range of 15-100 MeV. However, application of this method to low energy or very…

Accelerator Physics · Physics 2007-05-23 A. G. Shkvarunets , R. B. Fiorito , P. G. O'Shea

Near infrared diffuse optical imaging can be performed in reflectance and transmission mode and relies on physical models along with measurements to extract information on changes in chromophore concentration. Continuous-wave near-infrared…

Optics · Physics 2026-02-03 Kaiser Niknam , Mannu Bardhan Paul , Mini Das

Motivated by the looming "capacity crunch" in fiber-optic networks, information transmission over such systems is revisited. Among numerous distortions, inter-channel interference in multiuser wavelength-division multiplexing (WDM) is…

Information Theory · Computer Science 2014-10-09 Mansoor I. Yousefi , Frank R. Kschischang

We present a hardware-integrated security framework for LiFi networks through device fingerprint extraction within the IEEE 802.15.7 protocol. Our Optic Fingerprint (OFP) model utilizes inherent LED nonlinearities to generate…

Signal Processing · Electrical Eng. & Systems 2025-04-18 Ziqi Liu , Xuanbang Chen , Xun Zhang

We identify a route towards achieving a negative index of refraction at optical frequencies based on coupling between plasmonic waveguides that support backwards waves. We show how modal symmetry can be exploited in metal-dielectric…

Optics · Physics 2015-05-18 Ewold Verhagen , René de Waele , L. , Kuipers , Albert Polman

Radio frequency (rf) receivers using Rydberg atoms offer appealing features over classical sensors, such as their size, frequency tuning range, and lack of field absorption. In this work, we extend the application space by demonstrating a…

Atomic Physics · Physics 2025-02-25 Peter K. Elgee , Kevin C. Cox , Joshua C. Hill , Paul D. Kunz , David H. Meyer

For future wireless communication technologies, an increase in capabilities such as throughput is strongly expected. Transmission in the sub-THz bands (>90 GHz) seems to be the potential solution to meet the ever-increasing capacity demands…

Information Theory · Computer Science 2022-12-14 Yaya Bello , Jean-Baptiste-Doré , David Demmer

Improving the phase resolution of interferometry is crucial for high-precision measurements of various physical quantities. Systematic phase errors dominate the phase uncertainties in most realistic optical interferometers. Here we propose…

Quantum Physics · Physics 2018-04-03 Li Li , Yuan Li , You-Lang Zhang , Sixia Yu , Chao-Yang Lu , Nai-Le Liu , Jun Zhang , Jian-Wei Pan

The phase characteristics of reflecting and transmitting type twisted nematic liquid crystal based Spatial Light Modulators (SLMs) were measured using interferometry. Device parameters like contrast, brightness, input and output polarizer…

In this letter, we investigate rural large-scale path loss models based on the measurements in a central area of South Korea (rural area) in spring. In particular, we develop new close-in (CI) path loss models incorporating a diffraction…

Signal Processing · Electrical Eng. & Systems 2023-05-03 Jaedon Park , Hong-Bae Jeon , Jungho Cho , Chan-Byoung Chae