Early termination of flashlamp pumped dye laser pulses by shock wave formation

The problem of early termination of laser action in flashlamp pumped dye lasers is investigated. It is found that in high power, short pulse duration systems shock waves are created in the dye solution. Index inhomogeneities in the laser medium are created, and these lead to the termination of laser action. The velocity of propagation of the disturbance is measured. Some possibilities concerning the origin of these shock waves are examined. A design scheme that overcomes the effect of the disturbance in short pulse (</=5 microsec) systems is described.

The partial rate factor for nitration ipso to a methyl group

The partial rate factor for nitration ipso to a methyl group is c. three times that for substitution at the meta position.