TABLE OF CONTENTS The active synchronisation of longitudinal modes and the lasing of supershort radiation pulses were obtained for the first time in a helium-neon laser [1]. The passive synchronisation of the longitudinal modes was observed for the first time in a ruby laser [2] and in Nd-doped glass lasers [3,4]. In Ref. 55, the authors proposed a fluctuation model of the formation of supershort radiation pulses (SRP).
The model is based on the assumption that from a large number of fluctuation intensity transients, existing in the resonator at the start of the amplification process, as a result of the non-linear effect of the saturating absorber, the maximum transient is separated and amplified, and others are suppressed. The quantitative theory, describing the process of lasing of the laser with an antireflection filter, was developed in Ref. 6, in which it was shown that regular pulsations of radiation intensity can form in the laser with a saturating absorber without external regular effects. In Ref. 7 it was reported that in the Sixties the minimum duration of the SRP was reduced by an order of magnitude every two years, whereas in the Seventies, seven years was already required for reducing the duration of the SRP by an order of magnitude. The approximate duration of the light pulses to the fundamental limit in a single light period can be expected when using the lasers on active media with very wide gain lines.
The supershort radiation pulses are used widely in various areas of science and...
