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Full-Text Articles in Physics

Measuring Length Of Electron Bunches With Optics In Lcls-Ii, Nathan Ahn, Alan Fisher Sep 2019

Measuring Length Of Electron Bunches With Optics In Lcls-Ii, Nathan Ahn, Alan Fisher

STAR Program Research Presentations

Since the launch of the LINAC Coherent Light Source (LCLS) in 2009, there have been over 1,000 publications enabling pioneering research across multiple fields. Advances include: harnessing the sun’s light, revealing life’s secrets and aiding drug development, developing future electronics, designing new materials and exploring fusion, customizing chemical reactions, and many more. These discoveries gathered worldwide attention, and now work has begun on a new revolutionary tool, LCLS-II. The LCLS-II will pulse at a million times a second, compared to the 120 pulses from the LCLS. Within the LCLS-II, there are two chicanes, serpentine curves. As the electron beam passes …


Slow Light With Interleaved P-N Junction To Enhance Performance Of Integrated Mach-Zehnder Silicon Modulators, Marco Passoni, Dario Gerace, Liam O'Faolain, Lucio Claudio Andreani May 2019

Slow Light With Interleaved P-N Junction To Enhance Performance Of Integrated Mach-Zehnder Silicon Modulators, Marco Passoni, Dario Gerace, Liam O'Faolain, Lucio Claudio Andreani

Cappa Publications

Slow light is a very important concept in nanophotonics, especially in the context of photonic crystals. In this work, we apply our previous design of band-edge slow light in silicon waveguide gratings [M. Passoni et al, Opt. Express 26, 8470 (2018)] to Mach-Zehnder modulators based on the plasma dispersion effect. The key idea is to employ an interleaved p-n junction with the same periodicity as the grating, in order to achieve optimal matching between the electromagnetic field profile and the depletion regions of the p-n junction. The resulting modulation efficiency is strongly improved as compared to common modulators based on …


Spectroscopy Of Neon For The Advanced Undergraduate Laboratory, H. C. Busch, M. B. Cooper, C. I. Sukenik Jan 2019

Spectroscopy Of Neon For The Advanced Undergraduate Laboratory, H. C. Busch, M. B. Cooper, C. I. Sukenik

Physics Faculty Publications

We describe a spectroscopy experiment, suitable for upper-division laboratory courses, that investigates saturated absorption spectroscopy and polarization spectroscopy in a neon discharge. Both experiments use nearly identical components, allowing students to explore both techniques in a single apparatus. Furthermore, because the wavelength of the laser is in the visible part of the spectrum (640 nm), the experiment is well-suited for students with limited experience in optical alignment. The labs nicely complement a course in atomic or plasma physics, provide students with the opportunity to gain important technical skills in the area of optics and lasers, and can provide an introduction …


Thermally Stable Hybrid Cavity Laser Based On Silicon Nitride Gratings, Simone Iadanza, Andrei P. Bakoz, Praveen K. J. Singaravelu, Danilo Panettieri, Stefan Schulz, Ganga Chinna Rao Devarapu, Sylvain Guerber, Charles Baudot, Frédéric Boeuf, Stephen Hegarty, Liam O'Faolain Jul 2018

Thermally Stable Hybrid Cavity Laser Based On Silicon Nitride Gratings, Simone Iadanza, Andrei P. Bakoz, Praveen K. J. Singaravelu, Danilo Panettieri, Stefan Schulz, Ganga Chinna Rao Devarapu, Sylvain Guerber, Charles Baudot, Frédéric Boeuf, Stephen Hegarty, Liam O'Faolain

Cappa Publications

In this paper, we show the experimental results of a thermally stable Si3N4 external cavity (SiN EC) laser with high power output and the lowest SiN EC laser threshold to our knowledge. The device consists of a 250 μm sized reflective semiconductor optical amplifier butt-coupled to a passive chip based on a series of Si3N4 Bragg gratings acting as narrow reflectors. A threshold of 12 mA has been achieved, with a typical side-mode suppression ratio of 45 dB and measured power output higher than 3 mW. Furthermore, we achieved a mode-hop free-lasing regime in the range of 15–62 mA and …


Study Of Plasmonic Properties Of The Gold Nanorods In The Visible To Near Infrared Light Regime, Pijush Kanti Ghosh Aug 2016

Study Of Plasmonic Properties Of The Gold Nanorods In The Visible To Near Infrared Light Regime, Pijush Kanti Ghosh

Graduate Theses and Dissertations

Nanostructures of noble metals show unique plasmonic behavior in the visible to near-infrared light range. Gold nanostructures exhibit a particularly strong plasmonic response for these wavelengths of light. In this study we have investigated optical enhancement and absorption of gold nanorods with different thickness using finite element method simulations. This study reports on the resonance wavelength of the sharp-corner and round-corner rectangles of constant length 100 nm and width 60 nm. The result shows that resonance wavelength depends on the polarization of the incident light; there also exists a strong dependence of the optical enhancement and absorption on the thickness …