Transient behaviour of laser

J. Mizerski

Alireza Bahrampour, Mohammad Hossein Zandi

In this paper, we present a theory for analysing the transient behaviour of injection-locked lasers with monochromatic injection, wherein homogeneously broadened wide-band lasers with injection are analysed. In addition to boundary conditions, the initial distribution of the laser and the monochromatic injection signal fields are necessary for solving the governing equations. The Maxwell–Bloch equations are reduced to a system of ordinary differential equations with the initial conditions. In this paper, two approximation methods are introduced. These approximations are named the De-satellite signal approximation and the finite number satellite signal approximation, respectively. The finite number satellite signal approximation is used to study the transient behaviour of the satellite signal around the laser frequency in injection-locked lasers. The results are in good agreement with the data published by the previous studies on this topic.

L. A. Pokrovskii

E. Arimondo, C. Gabbanini, E. Menchi +2 more

The question of the behaviour of the LSA when a control parameter is a slowly varying function of time, has recently been raised [1]. The investigation of the transient behaviour of a LSA is interesting not only in connection with the problem of the response time of optically bistable systems but also because in any real experiment, if one wants to explore a phase diagram, the parameters have to be changed in time. Although the relaxation times of the molecular medium and the cavity response time are of the order of 100μs or smaller, the time constants characterising the transient regime of the LSA may be much longer because of the critical slowing down which appears near the limit points of the hysteresis cycle[2]

Kōichi Shimoda

Rainer Künnemeyer, Manfred Kock

Dense barium vapour (10 19 -10 21 m -3 ) produced in a heatpipe oven is irradiated by a laser light pulse (4.6*10 8 W m -2 , 300 ns, 30 pm) tuned to the resonant transition at lambda =553.55 nm. The transient population densities of various Ba I and Ba II states are measured and time resolved by means of the hook method. Simultaneously, the IR forward scattering (1.5 mu m; 1.13 mu m; 2.55 mu m) in the barium vapour is measured. When the laser pulse is tuned out of resonance the ion density decreases resonantly whereas the population densities of the low-lying Ba I states do not. This resonant ionisation behaviour is interpreted by means of radiative processes.