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On the power-bandwidth trade-off in bistable photonic switches
, Article Photonic and Phononic Crystal Materials and Devices IX, San Jose, CA, 27 January 2009 through 29 January 2009 ; Volume 7223 , 2009 ; 0277786X (ISSN) ; Abediasl, H ; Mehrany, K ; Khorasani, S ; Chamanzar, M. R ; Adibi, A ; Sharif University of Technology
2009
Abstract
Low power operation and high speed have always been desirable in applications such as data processing and telecommunications. While achieving these two goals simultaneously, however, one encounters the well-known powerbandwidth trade-off. This is here discussed in a typical bistable switch based on a two-dimensional photonic crystal with Kerr type nonlinearity. The discussion is supported by the nonlinear finite difference time domain (FDTD) simulation of a direct coupled structure with a home-developed code. Two cases of working near resonant and off- resonant are simulated to compare the power and the speed of the device in the two cases. It is shown that working nearresonance reduces the...
Optical bistable switching with Kerr nonlinear materials exhibiting a finite response time in two-dimensional photonic crystals
, Article Volume 7713 ; Proceedings of SPIE - The International Society for Optical Engineering, 12 April 2010 through 15 April 2010 , 2010 ; 0277786X (ISSN) ; 9780819481863 (ISBN) ; Monem Haghdoost, Z ; Abediasl, H ; Khorasani, S ; Mehrany, K ; Sharif University of Technology
Abstract
Effect of relaxation time on the performance of photonic crystal optical bistable switches based on Kerr nolinearity is discussed. This paper deals with optical pulses with the duration of about 50 ps. In such cases the steady state response of the optical device can be used to approximate the pulse evolution if the nonlinearity is assumed instantaneous, hence analytical solutions such as the coupled mode theory can be used to obtain the time evolution of the electromagnetic fields. However if the relaxation time of the material nonlinear response is also considered, changes in the power levels and in the shape of the hystersis loop is observed. In this case, we use the nonlinear finite...
Fluorescent microscopy using localized excitation source with gold nanotriangles: A computational study
, Article Photonics and Nanostructures - Fundamentals and Applications ; Volume 9, Issue 3 , 2011 , Pages 219-224 ; 15694410 (ISSN) ; Rashidian, B ; Vossoughi, M ; Sharif University of Technology
2011
Abstract
A new method for fluorescent microscopy has been proposed. Proposed method uses indirect excitation of fluorophores with nanometer localized illuminating source. Localized source is created at corners of gold nanotriangles which are deposited on glass substrate. Actually the combination of gold nanotriangle (deposited on glass) acts as active substrate (where species will be placed) for our proposed method. The structure will be scanned with a focused beam of laser (or combination of beams). Due to electric field enhancement in corners and edges of nanotringle (because of surface plasmons), third order nonlinear effect will be enhanced accordingly. Enhancement in third order nonlinearity...