**5. References**


[7] Koechner W. Solid State Laser Engineering, Berlin: Springer; 2006.

306 Numerical Simulation – From Theory to Industry

set of *qg*, *S* and *L* parameters.

**4. Conclusion** 

**Author details** 

**5. References** 

43.

R. Savastru, D. Savastru and S. Micloş

YAG Slab Laser with a LiF: F2-

I. Lăncrănjan

*Romania* 

simulation software was run several times in order to check the obtained results. This procedure suggests a design method for the investigated Nd:YAG laser oscillator/amplifier type, a method relying on the developed simulation procedure. The suggested design method is based on using components, mainly active medium and passive optical Q-switch cells with the parameters previously defined, but with possible different geometrical dimensions, an optimum being found for the best fit of desired output parameters with the

This chapter presents the results obtained in the numerical simulation of a passively Qswitched solid state laser system generating high power, high output energy singular laser pulses or laser pulses trains in pulsed CW or quasi-CW pumping. An important feature of the developed simulation method consists of an analysis of the differences between the first passively Q-switched laser pulse and the next, generated by a CW or a quasi-CW pumped laser system, regarding the recovery condition to the initial state of the passive optical Qswitch cell, which is analyzed in detail for the first time. As far as we know, concerning the passive optical Q-switching, this difference is not reported in literature so far as exhaustively studied. By observing this difference, a method for estimation of laser output pulse parameters is developed. The numerical simulation results are compared to the

experimental data and a fairly good agreement between them is observed.

*Advanced Study Center–National Institute of Aerospace Research "Elie Carafoli", Bucharest,* 

[1] Ready JF, Davis J, Berkmanns J, Kugler TR. Lasers for Materials Processing. In: Ready JF. (ed.) LIA Handbook of Laser Materials Processing. Oakland: Magnolia Press; 2001. p27-

[4] Dong S, Lü Q, Lancranjan I. 220 W Average Output Power From a Q-Switching Nd:

[6] Mercer CJ, Tsang YH, Binks DJ. A Model of a QCW Diode Pumped Passively Q-Switched Solid State Laser. Journal of Modern Optics 2007; 54 (12) 1685-1694.

Crystal. Optics and Laser Technology 1993; 25(3) 175-178.

[2] Steen WM. Laser Material Processing. Berlin, Heidelberg, New York: Springer; 1991. [3] Misawa H., Juodkazis S. 3D Laser Microfabrication, Weinheim: Wiley-VCH; 2006.

*National Institute of R&D for Optoelectronics INOE 2000, Magurele, Ilfov, Romania* 

[5] Siegman AE. Lasers, Sausalito: University Science Books; 1986.


[26] Lancranjan I, Miclos S, Savastru D. Numerical Simulation of a Passive Optical Q – Switched Solid State Laser - High Brightness Nd:YAG Laser Case. Journal of Optoelectronics and Advanced Materials 2011; 13 (5-6) 477-484.

**Chapter 15** 

© 2012 Autran et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

**Soft-Error Rate of Advanced SRAM Memories:** 

Single-event-effects (SEE) are the result of the interaction of highly energetic particles, such as protons, neutrons, alpha particles, or heavy ions, with sensitive regions of a microelectronic device or circuit [1-2]. They may perturb the device/circuit operation (e.g., reverse or flip the data state of a memory cell, latch, flip-flop, etc.) or definitively damage

With the constant downscaling of microelectronic devices, the sensitivity of integrated circuits to natural radiation coming from the space or present in the terrestrial environment has been found to seriously increase [3-5]. In particular, ultra-scaled memory integrated circuits are more sensitive to single-event-upset (SEU) and digital devices are more subjected to digital single-event transient (DSETs). The problem has been well-known for space applications over many years (more than forty years) and production mechanisms of single-event effects (SEE) in semiconductor devices by protons or heavy ions well apprehended, characterized and modeled [6]. In a similar way for avionic applications, the interaction of atmospheric neutrons with electronics has been identified as the major source of SEE [7]. For the most recent deca-nanometers technologies, the impact of other atmospheric particles produced in nuclear cascade showers on circuits has been clearly demonstrated (protons [8-9]) or is still under exploration for some exotic particles (pions and

With respect to such high-altitude atmospheric environments, the situation at ground level is slightly different. Of course, atmospheric neutrons are always the primary particles but, with a flux approximately divided by a factor ~300 at sea-level with respect to the flux at avionics altitudes, the Soft-Error Rate (SER) of circuits can be now affected by an additional source of radiation, usually neglected because completely screened by

and reproduction in any medium, provided the original work is properly cited.

**Modeling and Monte Carlo Simulation** 

Jean-Luc Autran, Sergey Semikh, Daniela Munteanu, Sébastien Serre, Gilles Gasiot and Philippe Roche

the circuit (e.g. gate oxide rupture, destructive latch-up events).

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/50111

**1. Introduction** 

charged muons [10-14]).

