The photoionization of a large organic molecule, tri‐n‐propyl amine, mixed with a 1‐atm CO2&sngbnd;N2&sngbnd;He gas is used to produce a high‐electron‐density uniform large‐volume laser plasma. Photoionization by a two‐photon two‐step process is found to be the dominant mechanism when illumination is by a xenon flashlamp employing a quartz envelope. Electron density on the order of 1013/cm3is obtained. The electrons are heated by an externally applied electric field less intense than that required to produce avalanche breakdown. Laser oscillation is observed on theP(20) line of the 10.6‐&mgr; CO2band with a maximum output of 300 mJ obtained from a 0.02‐liter active volume (corresponding to 15 J/liter). The energy output as a function ofE/Pis studied and found to peak at a value below breakdown.