Self-induced transparency on degenerate magnetic dipole transitions

Self-induced transparency has been observed on a $Q\left(2\right)\mathrm{}$-degenerate transition for the first time. Coherent interaction occurs as a short pulse from the ${}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}F=2\mathrm{}\to {}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}{F}^{\prime }=2\mathrm{}$, magnetic dipole transition of the atomic-iodine laser passes through a self-resonant iodine vapor. High transparency and considerable pulse delay at input pulse areas $\theta >\pi$, and small-pulse splitting at $\theta \simeq \pi$ characterized the phenomena.