Computer modelling and numerical simulation of the solid state diode pumped Nd:YAG laser with intracavity saturable absorber

Yashkir, Yuriy (2009): Computer modelling and numerical simulation of the solid state diode pumped Nd:YAG laser with intracavity saturable absorber.

Abstract

Stimulated emission in the Nd:YAG laser with a saturable absorber Cr:YAG is modelled as a superposition of interacting optical modes which are stable in a given optical cavity. The interaction of the active laser crystal and a passive Q-switch with diode pump and optical cavity modes is modelled with account of transversal two-dimentional variation of the pump field and of all participating optical modes. Each elementary volume of an active laser crystal and the Q-switching crystal interacts with all modes (this way modes are nonlinearly linked to each other), and every optical mode interacts with the whole laser crystal. This interaction is given by rate equations. Total number in this set of equations is given by the following formula Ne=2 * kmax * jmax^2 where kmax is number of cavity modes and jmax^2 is the total number of elementary volumes representing intracavity crystals. Most of simulation experiments presented in this paper were done with Ne=2*10^5 (kmax=20 , jmax^2 =10000). Special numerical tools were used to accelerate calculations without loss of precision. Simulation experiments for two laser devices provide quantitative validation of some experimentally observed effects (domination of the fundamental mode in a Q-swithed regime, multimode operation without Q switch) and predict performance of a laser with long pump pulses (trains of laser Q-switched pulses with pule-to-pulse mode switching)

• Item Type: MPRA Paper
• Language: English
• Keywords: laser, Q-switch, numerical model, thermal lens
• Subjects: C - Mathematical and Quantitative Methods > C6 - Mathematical Methods ; Programming Models ; Mathematical and Simulation Modeling > C61 - Optimization Techniques ; Programming Models ; Dynamic Analysis

References

Yuri Yashkir. Laser micromachining with passively q-switched intra cavity harmonic generator. SPIE, TD01:462-466, 2002.

Yuri Yashkir. Pulse shape control in a dual cavity laser: numerical modeling. Solid State Lasers and Amplifiers II, Proc. of SPIE, 6190(619018), 2006. Edited by Alphan Sennaroglu.

Yuri Yashkir. Numerical modeling of the phase-conjugate laser with an intra-cavity stimulated brillouin scattering mirror: Q-switching mode. Solid State Lasers and Amplifiers II, Proc. of SPIE, 6190(6190A), 2006. Edited by Alphan Sennaroglu.

Yuri Yashkir and Qiang Liu. Experimental and theoretical study of the laser micro-machining of glass using high- repetition-rate ultrafast laser. Solid State Lasers and Amplifiers II, Proc. of SPIE, 6190(6190V), 2006. Edited by Alphan Sennaroglu.

Yuri Yashkir and Henry van Driel. Passively q-switched 1.57-µm intra cavity optical parametric oscillator. Applied Optics, 38:2554-2559, 1999.

Yuri Yashkir and Yuriy Yashkir. Numerical modeling of the intra cavity stimulated raman scattering as a source of sub nanosecond optical pulses. Proceedings of SPIE - 5460, Solid State Lasers and Amplifiers, pages 220-227, 9 2004. Alphan Sennaroglu, James G. Fujimoto, Clifford R. Pollock, Editors.

Yuri Yashkir, Marc Nantel, and Bernard Hockley. Numerical simulation of the laser dynamics and laser/matter interactions, and its applications for laser micromachining. International Journal of Applied Electromagnetics and Mechanics, 19:373-377, 2004.