GENERATION OF 224-NM RADIATION BY STIMULATED RAMAN-SCATTERING OF ARF EXCIMER-LASER RADIATION IN A MIXTURE OF H-2 AND D-2

Raman shifting of tunable ArF excimer laser radiation in a mixture of H-2 and D-2 produces tunable radiation in the 224-nm region as a resul t of Stokes shifting the frequency of the fundamental radiation (193 n m) once in both H-2 and D-2. At a total pressure of 25 bars, a 19% H-2 in D-2 mixture is found to provide a maximum conversion efficiency (2 .5%) to the 224-nm range. Both fundamental and 224-nm radiation were u sed to record laser-induced. fluorescence excitation spectra of nitric oxide produced in an oxyacetylene flame. From the excitation spectra, we determined the tuning range of the 224-nm radiation to be 270 cm(- 1) with a linewidth of 0.9 cm(-1), which is similar to the fundamental laser radiation. We derived the exact Raman shift of the generated ra diation by comparing both excitation spectra which was found to be 714 2.3(5) cm(-1). (C) 1997 Optical Society of America.