Photoacoustic measurements of UV laser Pulse (266 nm) absorption in mixtures of water vapor with nitrogen

Results of photoacoustic measurements of absorption of 266 nm-laser pulses (the fourth harmonics of a YAG laser) by mixtures of water vapor and nitrogen, depending on the radiation intensity (0.5–10 MW cm −2 ) and H 2 O partial pressure (0–10 mbar), are presented. It is shown that the linear absorption (in the given range of intensities) increases with H 2 O partial pressure in a range 0–5 mbar and remains almost stable in a range 5–10 mbar exceeding the absorption in the pure nitrogen only by two orders of magnitude.