Superradiant emission dynamics of an optically thin material sample in a short-decay-time optical cavity

We report observations of optical superradiant emission and the atomic evolution it drives under conditions closely approximating those originally envisioned in the classic work of Dicke [Phys. Rev. 93, 99 (1954)]. Our experiment involves an optically thin solid sample in a short-lifetime optical cavity whose homogeneous coherence is cryogenically stabilized. Pulsed coherent excitation initiates superradiant emission which subsequently drives the sample to higher or lower states of coherence. Suppression of dephasing via cryogenics and propagation effects through use of an optically thin sample and cavity provides one of the dearest and cleanest examples of Dicke superradiance yet reported.