The negative hysteresis at low frequencies (less than 10 Hz) is observed in
a CO2 laser with modulated discharge current, The origin of this phenomeno
n is found in an additional loss modulation which can appear due to the hea
ting of intracavity elements by laser radiation, The results of numerical s
imulations on the base of the complex laser model are in a good agreement w
ith experimental results, (C) 2001 Published by Elsevier Science B.V.