Complications to optical measurements using a laser with an unstable resonator: a case study on laser-induced incandescence of soot.
Temporal behavior of pulses from a Q-switched Nd:YAG laser with an unstable resonator can vary significantly with radial position in the beam. Our laser provides pulses with position-dependent durations spanning 8-11.5 ns at 1064 nm and 7-10 ns at 532 nm. Pulses emerge first and have the longest duration at the center of the beam; they are shorter (by up to 4 ns) and increasingly delayed (by up to 10 ns) with increasing radial distance from the center. This behavior can have a dramatic effect on time-sensitive experiments, such as laser-induced incandescence of soot, if not taken into account.
Dansson
Mark A
MA
Combustion Research Facility, Sandia National Laboratories, P.O. Box 969, MS 9055, Livermore, California 94551-0969, USA.
Boisselle
Matthew
M
Linne
Mark A
MA
Michelsen
Hope A
HA