A pumping mechanism has been found for the CO/sub 2/ gas laser which involves the transfer of electronic energy from O/sub 2/ (/sup 1/..sigma..g/sup +/) to CO/sub 2/, the oxygen dropping to the /sup 1/DELTA g state. This appears to pump vibrational states of CO/sub 2/ which are above the lasing state (001), and which most deactivate collisionally to (001) before the emission pulse. A pure rotational, diatonic OH laser has been discovered which is collisionally pumped from excited vibrational levels. Typical pure rotational lasing is observed between J levels energetically equivalent to the vibrational frequency. These outputs have been compared for different rare gas collisional partners and it has been found that the intensity passes through a maximum for partners of intermediate mass, Ne or Ar. The HCN laser of 337 ..mu..m has been found to be susceptible to chemical pumping by the reaction, CN + H/sub 2/ ..-->.. HCN + H. It has not shown any indication of possessing an advantage in power over the HCN-discharge laser. It has also been pumped optically by an ultraviolet flash. The intensity here, too, is limited, but the behavior of the output as a function of nonreactive diluents is of scientific …

Laser oscillation at 337 and 311 ..mu..m has been obtained from HCN molecules prepared in vibrationally excited states by the reaction between cyanogen radicals and hydrogen molecules. It has likewise been observed in HCN raised to an electronically excited state by flash photolysis. The characteristics of the pulsed output are quite different in the two cases and beginnings have been made on experiments to probe the pumping and energy transfer kinetics. The rate determining step is not the reaction rate, but rather some relaxation process that eventually channels the excitation into the upper lasing state of one quantum each of CN stretch and bend. Detailed studies of the relative intensities of pure rotational lasing in OH and OD have been made. The rotational inversions are produced by rare gas-aided, adiabatic energy conversion from vibrational to rotational excitation. The process is rapid in comparison to rotational collisional relaxation. Using transfer parameters from the ''information theoretic'' analysis (R. D. Levine) computations have been made which reproduce the results in detail, providing support for the pumping mechanism proposed, and the applicability of the theory. Preliminary work on NH (from the HN/sub 3/ photolysis) has opened up extremely interesting questions concerning the electronic states …