A wavelength scannable XeCl oscillator-ring amplifier laser system

A holographic grating at grazing angle of incidence was used to achieve tunable, narrow bandwidth (0.005 nm) operation of a XeCl oscillator for injection locking of a ring amplifier. The amplifier’s narrow bandwidth output energy was constant and equal to the untuned, broadband output (∼15 mJ) in regions where injection locking was achieved. Scanning was provided by use of a stepping motor‐driven differential micrometer on the tuning mirror. This system was used to produce a laser excitation spectrum of hydroxyl radicals (OH) in a flame.