Kinetic gasdynamic model and calculation of the characteristics of an H2–HF gasdynamic laser utilizing purely rotational transitions

A theoretical investigation is made of two new possibilities of constructing a laser emitting far infrared radiation: one of them involves the use of the vibrational-rotational relaxation mechanism for the excitation of the higher rotational levels and the other is based on the transfer of vibrational energy from a slowly relaxing molecule to rotational levels of a hydrogen halide molecule. It is shown that fast gasdynamic cooling of a mixture of molecular hydrogen and hydrogen fluoride should ensure a gain of ~0.1 cm^–1 and an output radiation power density of ~1 W/cm³ in the wavelength range 17–22 μ.