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Full-Text Articles in Physical Sciences and Mathematics
Inductive Measurement Of Optically Hyperpolarized Phosphorous Donor Nuclei In An Isotopically Enriched Silicon-28 Crystal, P. Gumann, O. Patange, C. Ramanathan, H. Haas
Inductive Measurement Of Optically Hyperpolarized Phosphorous Donor Nuclei In An Isotopically Enriched Silicon-28 Crystal, P. Gumann, O. Patange, C. Ramanathan, H. Haas
Dartmouth Scholarship
We experimentally demonstrate the first inductive readout of optically hyperpolarized phosphorus-31 donor nuclear spins in an isotopically enriched silicon-28 crystal. The concentration of phosphorus donors in the crystal was 1.5×1015 cm−3, 3 orders of magnitude lower than has previously been detected via direct inductive detection. The signal-to-noise ratio measured in a single free induction decay from a 1 cm3 sample (≈1015 spins) was 113. By transferring the sample to an X-band ESR spectrometer, we were able to obtain a lower bound for the nuclear spin polarization at 1.7 K of ∼64%. The 31P-T2 measured with a Hahn echo sequence was …
Universality Of Returning Electron Wave Packet In High-Order Harmonic Generation With Midinfrared Laser Pulses, Anh-Thu Le, Hui Wei, Cheng Jin, Vu Ngoc Tuoc, Toru Morishita, C. D. Lin
Universality Of Returning Electron Wave Packet In High-Order Harmonic Generation With Midinfrared Laser Pulses, Anh-Thu Le, Hui Wei, Cheng Jin, Vu Ngoc Tuoc, Toru Morishita, C. D. Lin
Physics Faculty Research & Creative Works
We show that a returning electron wave packet in high-order harmonic generation (HHG) with midinfrared laser pulses converges to a universal limit for a laser wavelength above about 3µm. The results are consistent among the different methods: a numerical solution of the time-dependent Schrödinger equation, the strong-field approximation, and the quantum orbits theory. We further analyze how the contribution from different electron "trajectories" survives the macroscopic propagation in the medium. Our result thus provides a new framework for investigating the wavelength scaling law for the HHG yields.
Zinc Oxide Random Laser Threshold Enhancement Via Addition Of Passive Scatterers, Zachariah M. Peterson, Rolf Könenkamp, Robert Campbell Word
Zinc Oxide Random Laser Threshold Enhancement Via Addition Of Passive Scatterers, Zachariah M. Peterson, Rolf Könenkamp, Robert Campbell Word
Student Research Symposium
Zinc oxide (ZnO) is a wide bandgap n-type semiconductor with a variety of optical and electrical applications and many methods of fabrication. Strong optical scattering and photoluminescence from ZnO nanoparticles and films makes the material an ideal candidate for a random laser. Previous studies have shown both incoherent and coherent random lasing from ZnO films and particles agglomerations. When used as a passive scatterer in a laser dye gain medium, the addition of ZnO has been shown to improve the threshold for lasing. By combining active scattering ZnO with a passive scatterer, MgO, we show here that the lasing threshold …
Iron-Doped Zinc Selenide: Spectroscopy And Laser Development, Jonathan W. Evans
Iron-Doped Zinc Selenide: Spectroscopy And Laser Development, Jonathan W. Evans
Theses and Dissertations
We examine the quantum mechanics of optically active ions in crystals. Insight is developed which qualitatively explains the shape of the optical absorption and emission spectra of Fe2+ ions in II-VI materials. In addition to a discussion of the relevant theory, this work explores experimental techniques for absorption spectroscopy, laser-induced fluorescence spectroscopy, and upper-state lifetime measurements in detail. The data collected from these experiments are interpreted in the context of the theories developed herein. The theory and data are used to develop a simple model of the temperature dependence of the upper-state lifetime of Fe2+ ions in ZnSe. …
Progress Towards Terahertz Acoustic Phonon Generation In Doping Superlattices, Thomas E. Wilson
Progress Towards Terahertz Acoustic Phonon Generation In Doping Superlattices, Thomas E. Wilson
Thomas E. Wilson
Progress is described in experiments to generate coherent terahertz acoustic phonons in silicon doping superlattices by the resonant absorption of nanosecond-pulsed far-infrared laser radiation. Future experiments are proposed that would use the superlattice as a transducer in a terahertz cryogenic acoustic reflection microscope with sub-nanometer resolution.
Laboratory Manual For Physics Of Lasers And Modern Optics, 13th Ed, Stephen Ducharme
Laboratory Manual For Physics Of Lasers And Modern Optics, 13th Ed, Stephen Ducharme
Stephen Ducharme Publications
You will encounter challenging puzzles and explore new and exciting physical phenomena. You will be provided with sufficient tools, guidance and other resources, but what you learn depends on your inquisitiveness and creativity. This laboratory course is designed to serve two purposes: 1) To explore a variety of physical principles using the fascinating and diverse behavior of light. 2) To learn some of the principles behind the pervasive and expanding area of optical and laser technology. This course is suitable for students of science, life sciences, and engineering, or any student who is curious about light. The prerequisites are the …
Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft
Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft
Physics Faculty Publications
We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation …