Knowledge Bank

This preliminary work demonstrates the feasibility of obtaining a high resolution spectrum of cw laser excited fluorescence using a Fourier spectrometer. Using 1.3W of 5145 {\AA} multimode power from an $Ar+$ laser, fluorescence is excited mainly via the P(13) and R(15) (43,0) lines. Nearly all of the main fluorescence lines [P(13) , P(17), R(11), R(15)] originating from $v\prime =43$ are observed up to $v\prime \prime =85$. Their recorded full width at half maximum in the $7000-8000cm-1$ region is $0.023cm-1$. Rotational relaxation $(\Delta J\prime =2n)$ allows observation of numerous odd-$J\prime \prime$ satellite lines. The usual parameters are obtained which accurately represent the rotation-vibration levels of $I2X1\Sigma g\mathrm{<mrow\; data-mjx-texclass="ORD">+</mrow>}$ through $v\prime \prime =85$. The vibrational line intensities clearly show the alternation pattern predicted by the Franck-Condon factors of $Tellinghuisen.1$ The agreement between measured and calculated intensities is only qualitative for high $v\prime \prime$ values. This has important implications with respect to the $I2$ laser gain measurements discussed in the following talk.