The occurrence of pure rotational-to-rotational lasing from high J levels suggests that present rotational nonequilibrium mechanisms are inadequate to explain all lasing behavior of the HF laser. A possible mechanism for explaining this behavior is vibrational-to-rotational energy transfer. The usual assumption that vibrational relaxation occurs with rotational levels at equilibrium at the translational temperature is replaced with a near resonant multiquanta VR process that results in the formation of highly excited rotational states. Computer simulations incorporating VR relaxation predicted significant occurrence of rotational lasing. A simpler model that produced rotational nonequilibrium from pumping and P-branch lasing did not exhibit rotational lasing. Rotational lasing did not decrease energy available to P-branch lasing and produced effects resembling an increase in rotational relaxation rates. Rotational lasing is very sensitive to kinetics for both VR energy exchange and rotational relaxation.
© 1980 Optical Society of America
R. L. Kerber, R. C. Brown, and K. A. Emery, "Rotational nonequilibrium mechanisms in pulsed H2 + F2 chain reaction lasers. 2: Effect of VR energy exchange," Appl. Opt. 19, 293-300 (1980)