Stabilization of the emission frequency of a high-pressure waveguide $CO_2$ laser with the aid of resonances of saturated absorption in ${}^{192}OsO_4$ molecules

The emission frequency of a high-pressure waveguide $CO_2$ laser was stabilized using resonances of saturated absorption of the $P(14)CO_2$ line in ${}^{192}OsO_4$. The heterodyne method was used to measure (to within $2\cdot10^{-10}$) the relative frequency of a new strong resonance corresponding to the $A_2^2P(46)$ transition from the ground state of the ${}^{192}OsO_4$ molecule. The measurements were made relative to a narrow resonance of ${}^{192}OsO_4$ located near the center of the $P(14)CO_2$ line profile and corresponding to a transition from an excited state. The precision of the measurements was probably limited by stray amplitude modulation resulting from misalignment of the laser resonator caused by the operation of a piezoelectric ceramic plate.