Knowledge Bank

We have applied both microwave and radio frequency modulation to $CO2$ laser lines using only one CdTe modulator. As a result, a grid of closely spaced ($\Delta \nu \times 1MHz$) and tunable infrared frequencies is generated. This technique was used to perform infrared-infrared double resonance experiments on the molecules $\mathrm{<mrow\; data-mjx-texclass="ORD">28</mrow>}SiH4$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">28</mrow>}SiF4$ and to observe the Stark splitting due to extremely small dipole moments. As a preliminary result we obtained values for several dipole moment parameters which agree with measurements performed with other techniques.