Lasing characteristics of vapors of complex organic compounds

A theoretical investigation is made of laser action in vapors of complex organic compounds pumped by giant laser pulses. Allowance is made for the main feature of the gas phase, namely, a dependence of the spectroscopic and lasing characteristics of the active molecules on the vibrational energy stored in the ground and excited states. It is shown that a possible substantial increase in the average vibrational energy of the active molecules during the pump pulse causes an appreciable deterioration in the lasing characteristics of vapors compared with solutions, even in the most favorable case without induced absorption. An analysis is made using the parameters of a system similar to the experimental values for 1,4-bis[2-(5-phenyloxazolyl)]benzene (POPOP) vapor and allowance is made for neutral gases.