Refine your search
Collections
Co-Authors
Year
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Mohammad, Elham Jasim
- Statistical Simulation Methods
Abstract Views :450 |
PDF Views:0
Authors
Affiliations
1 Al-Mustansiriyah University, College of Sciences, Physics Department.
1 Al-Mustansiriyah University, College of Sciences, Physics Department.
Source
International Journal of Physics and Applications, Vol 5, No 1 (2013), Pagination: 13-18Abstract
This paper contains studying speckle characteristic, (the main problem in coherent images), some digital techniques for simulation have been presented in this paper to generate noise similar to speckle noise, this done by adopting (Chi-square, 2-Gaussian, Multi Method, and Sinusoidal) with different number of looks (1 to 5 look). Images can be simulated by multiplying, point to point, an in coherent image array by the simulated speckle data file. The size of the image and the speckle file must be equals.Keywords
Simulation, Speckle, Multiplicative Noise, Chi-square Distribution, Gaussian Distribution
References
- A. Glindemann, R. G. Lane, and J. C. Dainty, "Simulation of Timeevolving Speckle Patterns Using Kolmogorov Statistics", Taylor & Francis Ltd-1993.
- Ali-Zuky, "Quantitative Analysis of Synthetic Aperture Radar", Ph.D Thesis Submitted in Physics Dept., College of Science, Baghdad Univ., 1998.
- J. C. Dainty, "An Introduction to 'Gaussian' Speckle", SPIE Vol.243 Applications of Speckle Phenomena, 1980.
- J. C. Dainty, "Laser Speckle and Related Phenomena", Second Edition, New York, Springer-Verlag, 1975.
- J. W. Goodman, "Som Fundamental Proerties of Speckle", J. Opt. Soc. Am., Vol. 66, No. 11, pp. 1145-1150, 1976.
- V. S. Frost, K. S. Shanmugan; "The Information Content of SAR Image of Terrain", IEEE. Trans., AES-19, No.5, PP. 768-774, 1983.
- Alejandro C. Frery, Hans J. Müller, Corina de Costa Freitas Yanasse, & Sidnei J. Sant anna; "Amodel for Extremely Heterogeneous Clutter", IEEE. Transaction on Geoscience and Remote Sensing GE-35, No. 3, PP. 1-12, 1997.
- M. Tur, etal; "When is Speckle Noise Multiplicative ?" applied Optics, Vol. 21, No. 7, PP. 1157-1159, 1982.
- Multilayer Thin Films Dielectric Double Chirped Mirrors Design
Abstract Views :500 |
PDF Views:0
Authors
Affiliations
1 Al-Mustansiriyah University, College of Sciences, Physics Department.
1 Al-Mustansiriyah University, College of Sciences, Physics Department.
Source
International Journal of Physics and Applications, Vol 5, No 1 (2013), Pagination: 19-23Abstract
The double chirped mirror DCM appeared to meet the need to compensate for the gain crystal dispersion of solid state lasers in a broad wavelength range. Compared to earlier dispersion compensation techniques, they enabled remarkable improvements in the field of generating ultra short pulses. When ultra broad band gain media are used inside laser cavities, cavity dispersion plays an important role in determining the duration of the pulses when the laser is operating in mode locking regime. The aim of these notes is then to investigate which the act of cavity dispersion is on the shape and duration of a laser pulse that is propagating inside a femtosecond laser cavity, and how this dispersion can be compensated with the aid of suitable optical systems. In this paper a simple analytical equation takes an arbitrarily group delay dispersion GDD as an input function and gives the chirp law as an output. The chirp law determines the local Bragg wavelengths in the mirror. It allows the calculation of the thicknesses of the high and low index layers if the double chirp of the layers in the front part of the mirror is taken into account.
A simple chirped mirror (CM) can be achieved through dielectric coating with alternate layers of high and low index materials such as TiO2/SiO2 or TiO2LZH/SiO2LZH with varying thicknesses.
Keywords
Double Chirped Mirror, Bragg Wavenumber, Chirp Law, Group DelayReferences
- Bishnu P., "Frontiers in Guided Wave Optics and Optoelectronics", Book, ISBN 978-953-7619-82-4, pp. 674, China, (2010).
- Kartner F. X. et. al., "Double Chirped Mirror", USA, vol. 6, no 462, pp. 878, (2002).
- Al-Hillou A. M., Elham J. M., "Design and Study of Dielectric Double Chirped Mirrors in Ultra Short Femtosecond Pulse Lasers", Conf. 5th International on Resent Advance and Space Technologies RAST2011, IEEE, Page 608-611, Turkey, (2011).
- Elham J. M., Al-Hillou A. M., "Theoretical Design for Double Chirped Mirrors in Femtosecond Pulse Lasers", International Journal of Physics and Applications (IJPA), Delhi-India, (2011).
- Matuschek N., "Theory and Design of Double-Chirped Mirrors", PhD. thesis, University of Ulm, Germany, (1999).
- Design and Analysis Superprism Effects in 1D Photonics Crystal
Abstract Views :495 |
PDF Views:0
Authors
Affiliations
1 Ministray of Science & Technology Materials Chemistry & Physics.
2 Al-Mustansiriyah University, College of Sciences, Physics Department.
1 Ministray of Science & Technology Materials Chemistry & Physics.
2 Al-Mustansiriyah University, College of Sciences, Physics Department.
Source
International Journal of Physics and Applications, Vol 5, No 1 (2013), Pagination: 41-45Abstract
Extraordinary angle-sensitive light propagation, which we call a superprism phenomenon, was demonstrated at optical wavelength in photonic crystals (PCs) with one dimensional (1D) periodic structure. This research shows that multilayer optical thin film stack can exhibit superprism effect due to their large abnormal dispersions. We investigated and simulated this effect numerically in a 1D non-periodic film structure.Keywords
Superprism, Photonic Crystals, Group-propagationReferences
- B. Gralak, S. Enoch and G. Tayeb. "Anomalous ref ractive properties of photonic crystals". J. Opt. Soc. Am. ,17 (6) :101221020,(2000).
- L. J. Wu, M. Mazilu, T. Karle, T. F. Krauss. "Superprism phenomena in planar photonic crystals". IEEE J . Quantum Electronics,38 (7):9152918, (2002).
- H. Kosaka ,T. Kwawashma ,A. Tomita , et al."Superprism phenomena in photonic crystals". Phys. Rev. B,58 (16) :R100962R10099, (1998).
- H. Kosaka , T. Kwawashima ,A. Tomita , et al . "Superprism phenomena in photonic crystals: Toward microscale lightwave circuit s". J .LightwaveTechnology, 17 (11) :203222038, (1999).
- B. E. Nelson ,M. Gerken ,D. A. B. Miller ,R. Piestun. "Use of a dielectirc stack as a one2dimensional photonic crystal for wavelength demultipexing by beam shifting". Opt. Lett.,25 (20) :150221504, (2000).
- M. Gerken. PaperIFH2, OSA Conference on Integrated Photonics Research, Vancouver BC [Z]. (2002).
- M. Gerken, D. A. B. Miller. "Multilayer thin2film structures with high spatial dispersion". Applied Optics,42(7) :133021345, (2003).
- R. Zengerle, J. Mod. Opt. 34, 1589, (1987).
- B. E. Nelson, M. Gerken, D. A. B. Miller, R. Piestun,C.-C. Lin, and J. S. Harris, Jr., Opt. Lett. 25, 1502, (2000).
- M. Gerken and D. A. B. Miller, Appl. Opt. 42, 1330, (2003).
- M. Gerken and D. A. B. Miller, papers presented at the Materials Research Society's Spring Meeting, San Francisco, Calif., (2003).
- A. Yariv and P. Yeh, J. Opt. Soc. Am. 67, 438, (1977).
- M. Centini, C. Sibilia, M. Scalora, G. D'Aguannol, M. Bertolotti, M. J.Bloemer, C. M. Bowden, and I. Nefedov, Phys. Rev. E 60, 4891, (1999).
- Theoretical Design of Picoseconds Fabry-perot Filter and Study the Dispersion Using Coupled Mode Equation
Abstract Views :535 |
PDF Views:0
Authors
Affiliations
1 Al-Mustansiriyah University, College of Sciences, Physics Department.
1 Al-Mustansiriyah University, College of Sciences, Physics Department.
Source
International Journal of Physics and Applications, Vol 5, No 1 (2013), Pagination: 47-57Abstract
Fabry-Perot interferometers or etalons are used in optical modems, spectroscopy, lasers, and astronomy. In this paper we used the coupled mode equation to design the Fabry-Perot filter and study the picosecond dispersion, where, the picosecond is 10−12 of a second. That is one trillionth, or one millionth of one millionth of a second, or 0.000 000 000 001 seconds. Coupled mode analysis is widely used in the field of integrated optoelectronics for the description of two coupled waves traveling in the same direction. The program is written in MATLAB to simulate and analysis the Fabry-Perot properties.Keywords
Fabry–perot Filter, Coupled Mode Theory, Coupling Coefficient, FinesseReferences
- Macleod H. A., "Thin-Film Optical Filters: 3rd Edition", Published by Institute of Physics Publishing, wholly owned by The Institute ofPhysics, London, UK, (2001).
- Tamir S., "Fabry-Perot Filter Analysis and Simulation Using MATLAB", (2010).
- Wiemer M., "Double Chirped Mirrors for Optical PulseCompression", (2007).
- Cakmak B., Karacali T. and Yu S., "Theoretical Investigation of Chirped Mirrors in Semiconductor Lasers", Appl. Phys, 33-37, (2005).
- Pierre T., "Negative group delay times in frustrated Gires-Tournois and Fabry- Perot interferometers", IEEE Journal of Quantum Electronics, vol. 33, no. 4, pp. 519-526, (1997).
- Adobe PDF-View as html,"Definition of Group Delay", (2008): http://www.dsprelated.com/blogimages/AndorBariska/NGD/ngdblog.pdf.
- Imran T., Hong K. H., Yu T. J. and Nam C. H., "Measurement of the groupdelay dispersion of femtosecond optics using white-light interferometry", American Institute of Physics, Review of Scientific Instruments, vol. 75, pp. 2266-2270, (2004).
- Kitano M., Nakanishi T. and Sugiyama K., "Negative Group Delay and Superluminal Propagation: an Electronic Circuit Approach", IEEE J. Select. Topics Quantum Electronics, vol. 9, no. 1, (2003).
- Woodley J. F. and Mojahedi M., "Negative Group Velocity and Group Delay in Left-Handed Media", Am. Phys. Soc., 70 046603-1, (2004).