<title>Magnetic modulation of subsonic COIL</title>

Abstract

A variable magnetic field was incorporated into a 1D model of subsonic COIL model with a mixing length to include its influence on the stimulated emission cross-section and other lasing parameters. The model includes a fairly complete chemical kinetics of energy transfer from the excited molecular oxygen to the injected iodine, accounting also for the gas temperature effect and a simplified mixing description of oxygen and iodine molecules. The variable magnetic field transforms the CW regime in a pulsed operation. The numerical procedure gives a possibility to tackle an arbitrary temporal dependence of the imposed magnetic field and to calculate directly the response of the laser output. The calculation was focused on the experimental data measured with the subsonic version of the COIL device in the Institute of Physics, Prague, modulated by a saw-tooth magnetic pulses. Although the model gives a reasonable agreement for the CW regime it is difficult to match the exact shape of the measured magnetically switched laser pulses with the calculated one. In this contribution we shall demonstrate various additional refinements of the model to improve the agreement with the measured pulse shape.