Line broadening and shift coefficients of acetylene at 1550Â nm

Pressure broadening and shift coefficients have been measured for the ν1 + ν3 band of acetylene, C2H2, broadened by N2, H2, D2, air, and the noble gases at 295 K. Coefficients are reported for lines between 6470 and 6612 cm−1 (1512-1546 nm). The pressure broadening coefficients are in general agreement with those reported for other vibrational bands, indicating that they are insensitive to vibrational excitation. The pressure shift coefficients, by contrast, are found to differ substantially among vibrational bands.