Abstract
The generation of slow and fast light in the same transient hole-burning experiment by two laser-frequency modulation methods is reported. The schemes allow for rapid switching between slow and fast light on very short time scales. Experiments were carried out in the R-1(+/- 3/2) line of a pale green (0.04 wt. % Cr) emerald, Be3Al2Si6O18:Cr3+ in pi polarization (E parallel to c) at 2.3 K in a low magnetic field B parallel to c of 12 mT. Maximum delays and advancements for a 115 ns Gaussian pulse were 65 and -25 ns, respectively, corresponding to group indices of 7.8 . 10(3) and -3 . 10(3). The present schemes point to possible applications in all-optical switches. (C) 2015 Optical Society of America