ATOMIC OXYGEN LINE-SHAPE MEASUREMENT AT 130 NM WITH RAMAN-SHIFTED LASER

The absorption of vacuum ultraviolet light by atomic oxygen has been m easured in the electric are-driven shock tube facility at NASA Ames Re search Center. A probe beam is generated with a Raman shifted ArF exci mer laser. By suitable tuning of the laser, absorption is measured ove r a range of wavelengths in the region of the P-3(1)-S-3(0) line at 13 0.49 nm. The Lorentzian full width at half-height due to collision bro adening by atomic oxygen is measured at various wavelengths up to 1200 linewidths away from the line center. The measured linewidth is three times larger than that calculated with an established radiation code, and a possible explanation for the difference is discussed. This expe riment demonstrates the viability of high order Raman shifters as ligh t sources in impulse facilities where singnal averaging is not possibl e.