Search

Your search keyword '"Fragnito, H. L."' showing total 160 results
Start Over Author "Fragnito, H. L."
160 results on '"Fragnito, H. L."'

1. Multi-wavelength source at ITU-T grid based on ultra-flattened dispersion photonic crystal fibers

Author

S. Jr., Arismar Cerqueira, Marconi, J. D., Gabrielli, L. H., Rieznik, A. A., Hernandez-Figueroa, H. E., Fragnito, H. L., and Knight, J. C.

Subjects
Physics - Optics
Abstract

We report on the development of a multi-wavelength source locked to the ITU-T grid at 100 GHz spacing and based on ultra-flattened dispersion photonic crystal fibers. The ITU-T grid frequencies are generated by taking advantage of multiple four-wave mixing processes. We experimentally obtained 250 products spanning over 200nm by launching 03 strong pump signals. Simulations based on Split-Step Fourier Method have been carried out in order to investigate and improve the performance of this nonlinear optical device., Comment: 5 pages, 5 figures

Published
2008

2. Coherent Control of Ultra-High Frequency Acoustic Resonances in Photonic Crystal Fibers

Author

Wiederhecker, G. S., Brenn, A., Fragnito, H. L., and Russell, P. St. J.

Subjects
Physics - Optics
Abstract

Ultra-high frequency acoustic resonances ($\backsim$2 GHz) trapped within the glass core ($\backsim$1 $\mu$m diameter) of a photonic crystal fiber are selectively excited through electrostriction using laser pulses of duration 100 ps and energy 500 pJ. Using precisely timed sequences of such driving pulses, we achieve coherent control of the acoustic resonances by constructive or destructive interference, demonstrating both enhancement and suppression of the vibrations. A sequence of 27 resonantly-timed pulses provides a 100-fold increase in the amplitude of the vibrational mode. The results are explained and interpreted using a semi-analytical theory, and supported by precise numerical simulations of the complex light-matter interaction., Comment: 4 pages, 3 figures, 3 avi movies (external link) - accepted in PRL

Published
2007
Full Text
View/download PDF

10. Optically Pumped FIR Lasers

Author

Scalabrin, A., Vasconcellos, E. C. C., Cruz, C. H. Brito, Fragnito, H. L., Schawlow, Arthur L., editor, Guimaraes, Wladimir O. N., editor, Lin, Chhui-Tsu, editor, and Mooradian, Aram, editor

Published
1981
Full Text
View/download PDF

13. Frequency comb expansion based on optical feedback, highly nonlinear and erbium-doped fibers

Author

Melo, S., A. R., Do Nascimento J. r., S. Arismar, Cerqueira J. r., Carvalho, L. H. H., Pataca, D. M., Oliveira, J. C. R. F., Fragnito, H. L., and Assis De Souza Melo, Suzanne

Subjects
Materials science, Nonlinear optics, Four-wave mixing, Frequency comb, Electronic, Optical and Magnetic Materials, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Physical and Theoretical Chemistry, Physics::Optics, chemistry.chemical_element, Erbium, Optics, Atomic and Molecular Physics, Electronic, Optical and Magnetic Materials, Comb filter, Mixing (physics), business.industry, Nonlinear system, chemistry, Cross-polarized wave generation, and Optics, business
Abstract

This works presents an efficient technique for generating multi-wavelength sources, which consist of an expanded optical frequency comb based on the nonlinear process of multiple four-wave mixing. The nonlinear efficiency is significantly enhanced by the use of the proposed scheme based on optical feedback, highly nonlinear and erbium-doped fibers. Numerical and experimental results illustrate its efficiency and applicability by expanding a comb from 20 to over 200 coherent lines spaced by only 12.5 GHz.

Published
2014

17. Electroluminescence from amorphous silicon carbide heterojunctions under reverse biased conditions.

Author

Alvarez, F., Fragnito, H. L., and Chambouleyron, I.

Subjects
*SILICON carbide, *AMORPHOUS substances, *PHOTOCONDUCTIVITY
Abstract

Observes the emission of visible radiation from reverse biased amorphous silicon carbide p-i-n junctions at room temperature. Equation of gaseous mixture used during the deposition of intrinsic layer; Measurements of current versus voltage at different temperatures to determine the mechanism of carrier injection; Information on incorporated centers in the case of photoconductivity.

Published
1988
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results