Transmission enhancement of ultraslow light in an atom shelved model of spectral hole burning solids.

We present transmission enhancement of ultraslow light in an inhomogeneously broadened spectral hole-burning solid medium by using precedent dummy light. The function of the dummy light is to burn a half-depth narrow spectral hole in an optically shelved solid system and to maintain the system optically transparent to the probe light, where the probe must experiences ultraslow group velocity due to the narrow spectral hole. The observed transmission increase is as high as 7 times compared with self-induced ultraslow light [J. Hahn and B. S. Ham, Opt. Express 16, 16723 (2008)], where the transmission enhancement is equivalent to 10(5) amplification considering an optical depth of d = 10.