“…[ 39–41 ] The laser generation manifests itself in different ways. In most of the works, the main conclusion about the lasing nature of the emission is made based on the narrow line width and threshold behavior [ 2–5,7–16,18,19,21,22,25–27,30,32–43 ] of the emission. Rarely, the emission polarization was tested, [ 11,13,23,24,27,28,32–37,39 ] the direct observation of the light field distribution in the resonator was made, [ 10,13,14,16,18,19,21,34,39,41 ] or the laser emission directionality was observed.…”