Murat B. Suvorov

Phase-conjugate mirror on the basis of the pulsed CO2 laser with the intracavity nonlinear medium

A phase-conjugate (PC) mirror on the basis o InAs in a cavity o a TEA CO2 laser was studied. Efficiency B o such a PC-mirror is 1O% ror the signal coherent to the pump waves and 3-5% ror the incoherent signal. The PC fidelity or a signal wave in the scheme studied is shown to be as high as 1 00%. The insertion of Inks plate into the laser cavity is round to result in : i) the stretching o the FWIIM pulse duration, ii) the stabilization of the mean intracavity radiation intensity, iii) the Lonnation o the hypergaussian intracavity beam profile due to strong nonl inear absorp t ion in Inks ; and due to the nonl inear change of index in Inks iv) the diffraction of the laser radiation on intracavity apertures and v) the transition from periodic to chaotic pulsations of the output power.

Regular and random output-power pulsations of a TEA CO2 laser with an intracavity nonlinear medium

The lasing dynamics of a pulsed atmospheric-pressure (TEA) CO2 laser with a nonlinear medium (semiconductor InAs or InSb) inside the cavity is experimentally investigated. It is observed that introduction into the CO2 cavity of nonlinear media having high nonlinear-absorption and a nonlinear refractive index leads, on the one hand, to a limitation of the emission intensity in the cavity and to an increase of the pulse duration (FWHM) from ∼0.1 μsec to ∼2 μsec, and on the other to appearance, on the output-power pulse envelope, of spikes having irregular amplitudes and durations, and separated by irregular intervals. It is established that the transition from the intermode-beat-induced regular pulsations to chaos has an emission-intensity threshold.