Coherent population trapping in a finite-size buffer-less cell

We have investigated theoretically the formation of a coherent population trapping resonance in a finite-size vapour cell without a buffer gas. We have demonstrated the novel mechanisms of the resonance narrowing: an analogue of the Dicke effect and light-induced narrowing. In the light-induced narrowing regime the parameters of the coherent population trapping resonance weakly depend on the cell size and the type of coating