Knowledge Bank

We have performed an infrared-microwave wave double resonance experiment in $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CH3F$. Specifically, the P(32) lines of a $CO2$ laser pumps the $J,K=4,3\to 5,3$ transition in the $\nu 3$ band of $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CH3F$. Operation of the laser in the Q switch mode has enabled us to measure the rotational relaxation time $T1$. These results are interpreted in terms of a general theory of microwave-infrared transient phenomena. The equations, which are analogs of the NMR Bloch equations, are analyzed to provide comparisons with several related experiments.