A STUDY OF SOLID STATE LASER PASSIVE OPTICAL Q-SWITCHING OPERATION REGIME (Part 1)

Abstract

This paper is the first of a four series treating, theoretically with experimental comparison, the issue of solid state laser passive optical Q-switching regime. In this first paper the technique of solid state lasers passive optical Q-switching is numerically investigated considering the case of longitudinally and transversally uniform photon, population inversion and absorption centres densities. The coupled differential equations defining photon, population inversion and absorption centres densities are numerically solved being the basis of passively optical Q-switched laser functional simulation. The numerical simulations are performed using the several software packages, mostly SCILAB programs. The developed SCILAB programs can be used for a large range of saturable absorption centre and active media parameters, mainly the initial (low signal) optical transmittance of the passive optical Q-switch. The developed FORTRAN and SCILAB programs can be applied for passively Q-switched solid state lasers of several types emitting at several NIR wavelengths, in domain 1 ÷ 2 μm. For validating the numerical simulation results are compared with The results of the numerical simulation are compared with experimentally obtained ones, in the case of a LiF:F2 passively Q-switched Nd:YAG. A good agreement between the two kinds of results is observed.