Colloquium featuring Heejeong Jeong - Hong Kong University of Science and Technology
Optical precursors are transient electromagnetic wave packets propagating precisely at the speed of light in vacuum through a dispersive and absorptive dielectric. Even though its existence was conjectured by Sommerfeld and Brillouin 100 years ago, the detection seemed to be impossible due to its exceedingly small amplitude and femtosecond time scale in ordinary linear dispersive media.
In this talk, I present a story of the first direct observation of optical precursors using a magneto-optical trap (39K, potassium) and its extension to electromagnetically induced transparency (EIT) media. By stacking of “resonant” precursors and slow light in an EIT medium, more than 800% of the optical burst was achieved with no external gain. Also, I will talk about the universal features and underlying physics of the optical precursors beyond the predictions from modern asymptotic theory. Optical precursors will play a significant role as an ultra-precise clock, jitter corrector, and time delay unit in an integrated quantum communication network.