HYDRODYNAMIC PHENOMENA IN LASER PHYSICS - MODES WITH FLOW AND VORTICES BEHIND AN OBSTACLE IN AN OPTICAL CHANNEL

The transverse patterns of an active resonator with cylindrical optics are investigated. This resonator configuration corresponds to a ''cha nnel'' form of the potential for the ''photon fluid.'' Simultaneous em ission of different transverse modes along the channel, periodic nucle ation of vortices in the form of a vortex street (vortices of alternat ing senses of rotation appearing in a flow behind an obstacle), accele rated flow in a ''tilted channel,'' and destabilization of the one-dir ectional flow in the channel are demonstrated and interpreted in terms of tilted waves and beating of channel modes, as well as in fluid ter ms, illustrating the fluid dynamics correspondence of class-A lasers.