Pulsed laser operating on the first vibrational overtone of the CO molecule in the 2.5-4.2-mu m range: 1. Multifrequency lasing

Characteristics of a pulsed, multifrequency electroionisation CO laser oper ating on the first vibrational overtone of the CO molecule are studied expe rimentally and theoretically. It is shown experimentally that a pulsed, mul tifrequency overtone CO laser is an efficient source of coherent radiation in the 2.5-4.1-mum region whose specific output reaches 50 J 1(-1) amagat(- 1) and the electro-optical efficiency amounts to 11%, A theoretical analysi s based on experimental data shows the feasibility of obtaining overtone em ission with efficiency as high as similar to 20%. The alternation of the in tensity of vibrational bands in the over-tone CO laser is discussed. This e ffect is caused by the cascade mechanism of formation of the emission spect rum. The comparison of experimental data with calculations showed that they agree well with respect to spectral and energy characteristics of the over tone CO laser. Moreover, it revealed the necessity of refinement of the kin etic model of the active medium of the CO laser for obtaining an adequate d escription of time parameters of a laser pulse.