The absorption line shapes of the $R_1\mathrm{}\left(1\right)-R_1\mathrm{}\left(5\right)\mathrm{}$ lines of HF have been measured as a function of pressure for pure HF and with Ar and Kr as buffer gases by means of a cw tunable $F_B$ (II)-type color-center laser operating in the wavelength range from 2.25 to 2.65 μm. Line-broadening coefficients are determined and Einstein $A$ coefficients are evaluated from the line shapes. Collisional narrowing is observed for the $R_1\mathrm{}\left(4\right)\mathrm{}$ line with Kr as the buffer gas.

• Received 5 February 1979

DOI:https://doi.org/10.1103/PhysRevA.20.229