LOW-FREQENCY PULSATIONS IN A HE-XE LASER WITH SEVERAL TRANSVERSE-MODES - EXPERIMENTAL AND NUMERICAL-STUDIES

Spatial pattern pulsations are observed at frequencies much less than the intermode beat frequencies in a He-Xe laser operating at 3.51 mum. Numerical studies indicate that such low-frequency pulsations can ari se from secondary beat notes between the frequencies of unequally spac ed modes. The decay rate of the active medium is an important paramete r which sets the scale for mode pulling without locking, which leads t o these pulsations.