A5042441428- Atomic and Subatomic Physics Research
- Nonlinear Waves and Solitons
- Quantum chaos and dynamical systems
- Cold Atom Physics and Bose-Einstein Condensates
- Mathematical Dynamics and Fractals
- Spectroscopy and Laser Applications
- Advanced Fiber Laser Technologies
- Laser Design and Applications
- ZnO doping and properties
- Semiconductor materials and devices
- Quantum optics and atomic interactions
- Advanced Differential Equations and Dynamical Systems
- Nanofabrication and Lithography Techniques
- Differential Equations and Numerical Methods
- Advanced Algebra and Geometry
- Solid State Laser Technologies
- Plasma Applications and Diagnostics
- Optical properties and cooling technologies in crystalline materials
- Advanced Fiber Optic Sensors
- Geometric Analysis and Curvature Flows
- Advanced Topics in Algebra
- Plasma Diagnostics and Applications
- Quantum, superfluid, helium dynamics
- Diamond and Carbon-based Materials Research
- Photonic Crystal and Fiber Optics
University of Illinois Urbana-Champaign
2016-2025
Cygnus (United States)
2020-2024
Sorbonne Université
2024
École Polytechnique
2024
Laboratoire pour l'utilisation des lasers intenses
2024
Fraunhofer Institute for Interfacial Engineering and Biotechnology
2022
Ruhr University Bochum
2022
Polytechnique Montréal
2022
University of Bari Aldo Moro
2022
VDE Prüf- und Zertifizierungsinstitut (Germany)
2022
Laterally configured diamond photoconductive semiconductor switches (PCSS) with a buried, metallic p + current channel are reported.Above bandgap (λ ≤ 226 nm) optical triggering enables responsivity of over 130 mA/W.The use low-impurity semi-insulating as an active absorption layer fast rise and fall times (~2 ns) on/off ratios greater than 10 11 .The PCSS excited laser energy 20 nJ per pulse passes high density (44 A/cm) under DC bias 60 V, thanks to the buried channel.The reported devices...
In this paper we prove the Birkhoff-Poritsky conjecture for centrally-symmetric $C^2$-smooth convex planar billiards. We assume that domain $\mathcal{A}$ between invariant curve of $4$-periodic orbits and boundary phase cylinder is foliated by $C^0$-invariant curves. Under assumption billiard an ellipse. For original formulation show if a neighborhood has $C^1$-smooth foliation caustics rotation numbers in interval $(0; 1/4]$, then language first integrals one can assert inside $\gamma$...
More than 25 W of average power and >800 peak have been generated at λ=172 nm (hν=7.2 eV) in the vacuum ultraviolet (VUV) from Xe2 molecule flat, 10 × cm2 lamps having an active area volume 80 <60 cm3, respectively. Powered by least two interlaced arrays microplasmas within cavities fabricated into interior surface <6 mm thick lamp, these electrical-to-optical conversion efficiency >20%. For a bipolar voltage waveform driving frequency 137 kHz 54% Xe/Ne gas fill mixture 300 K pressure 550...
One of the most interesting problems in theory Birkhoff billiards is problem integrability. In all known examples integrable billiards, billiard tables are either conics, quadrics (closed ellipsoids as well unclosed like paraboloids or cones), specific configurations conics quadrics. This leads to natural question: there other billiards? The conjecture states that if inside a convex, smooth, closed curve integrable, then an ellipse circle. this paper we study cone $\mathbb{R}^n$. We prove...
Photoconductive semiconductor switches (PCSSs) are fabricated on type IIa diamond substrates with varying boron and nitrogen impurity levels (&lt;1014–1016 cm−3). The photoresponse of lateral PCSS is reported over the incident laser wavelength range (212–240 nm), energy per pulse (5–65 μJ), DC bias (−1.2 to +1.2 kV). device lowest concentration achieves highest normalized responsivity 9.1 × 10−8 A-cm/W-V, peak photocurrent 8.0 A, on/off ratio 2.3 1011 at a kV potential for even higher...
In this paper, we deal with the classical question of existence polynomials in momenta integrals for geodesic flows on 2-torus. For quasilinear system coefficients polynomial integral, investigate region (so-called elliptic region) where two eigenvalues are complex conjugate. We show that quartic other real and necessarily genuinely nonlinear. This observation, together property to be rich (semi-Hamiltonian), enables us classify regions completely. prove these integral is always reducible....
Precision photoablation of bulk polymers or films with incoherent 172 nm radiation from flat, microplasma array-powered lamps provides the foundation for a photolithographic process in which an acrylic other polymer serves as dry photoresist.
In this paper, we give a short survey of recent results on the algebraic version Birkhoff conjecture for integrable billiards surfaces constant curvature. We also discuss magnetic billiards. As new application technique, study existence polynomial integrals two-sided introduced by Kozlov and Polikarpov. This article is part theme issue ‘Finite dimensional systems: trends methods’.
Two color optical pumping, both above (anti-Stokes pump or ASP) and below (Stokes pump) the lasing wavelength, was adopted to reduce net quantum defect (QD) in a solid-state Yb-doped fiber laser. The reduction QD achieved by converting substantial portion of gain medium's phonons directly into useful photons through dual-wavelength excitation (DWE) mechanism. Since this is usual processes absorption stimulated emission associated with lasing, high efficiency can be maintained. Both time...
A two color process for optical pumping of the Rb D2 line laser (λ = 780 nm) in vapor-rare gas mixtures is demonstrated to yield an overall quantum efficiency &gt; 1. Combining photoexcitation blue satellite Rb-Xe or Rb-Ar with free ← A2Π12←X2Σ12+ transition at large internuclear separation (R 5 Å) also increases and pump absorption coefficient, relative single color, B X pumped system, by a factor 1.7 more than order magnitude, respectively. Simultaneous photopumping thermal collision...
Abstract A little more than two decades after the introduction of first microcavity plasma devices, a growing body commercial products based on remarkable properties these low‐temperature, atmospheric plasmas is now available. Following brief review early microplasma lamp development, this article describes microplasma‐based devices and systems currently being manufactured for applications in photolithography, photopatterning, other nanofabrication processes, such as atomic layer deposition,...
Oxide films of the quality required for fabrication electronic and photonic devices are typically deposited at elevated temperatures thermal equilibrium, thereby adversely impacting budgets. We report deposition patterning silicon dioxide (SiO2) high electrical optical on Si(100) or polymer substrates in a N2 atmosphere 300 K by photochemical conversion thin liquid tetraethoxysilane (TEOS) layers with narrowband vacuum ultraviolet radiation [vacuum (VUV), 172 nm] provided efficient...
We associate a periodic two-dimensional Schrodinger operator to every Lagrangian torus in CP^2 and define the spectral curve of as Floquet spectrum this on zero energy level. In event minimal tori correspond potential operators. show that Novikov-Veselov hierarchy equations induces integrable deformations preserving curve. also highest flows space smooth solutions Tzizeica equation are given by hierarchy.
Cs atomic lasers, operating on the D2 line and pumped by photoassociation of Cs-rare gas thermal collision pairs, have been examined in mixtures vapor with Ar, Kr, or Xe. Photoexcitation B 2Σ+ − X molecular transition (i.e., blue satellite transition) at 836.7 nm (Cs-Ar), 841.1 (Cs-Kr), 842.7 (Cs-Xe) yields lasers 852.1 whose characteristics (optical-to-optical conversion efficiencies, pump energy threshold, temperature dependence) are a reflection structure interatomic potential associated...
We report the selective population of Rb or Cs np ^{2}P_{3/2} (n=5, 6; F=4, 5) hyperfine states by photodissociation a transient, alkali-rare gas diatomic molecule. Circularly polarized (σ^{-}), amplified spontaneous emission (ASE) on D_{2} line (780.0 and 852.1 nm, respectively) is generated when Rb-Xe Cs-Xe ground state collision pairs are photoexcited σ^{+}-polarized optical field having wavelength within blue satellite continuum, associated with B^{2}Σ_{1/2}^{+}←X^{2}Σ_{1/2}^{+}...
Multiplication of the pulse repetition frequency (PRF) a compact, mode-locked fiber laser by factor as large 25 has been achieved with two coupled Fabry-Perot (FP) resonators low finesse (F = 2). Reducing FP at least orders magnitude, relative to previous multiplication architectures, effect stabilizing oscillator respect pulse-to-pulse amplitude, dropped pulses, and other effects cavity detuning. Coupling cavities, each encompassing 3.3-3.6 cm length fiber, in hybrid geometry resembling...
Abstract A new concept of an all optical, dual-fiber-based Pirani thermal vacuum gauge is proposed and demonstrated. The configuration utilizes two fibers: one that produces heat, responds to the resultant exchange. temperature latter fiber a function heat transfer through gas in which it resides. active heat-generating luminescence-quenched, heavily Yb 3+ -doped optical efficiently energy when optically pumped. sensor implemented with conventional commercial Bragg grating. Both fibers are...