Superluminescent diode excitation of femtosecond accumulated photon echoes

Abstract
Using a superluminescent diode, we observed femtosecond accumulated photon echoes in 1,1′-diethyl-4,4′-quinodicarbocyanine iodide embedded in polyvinyl acetate. The output of the superluminescent diode directly excited the sample to produce photon echoes. By using a simple experimental system we obtained a temporal resolution as high as 100 fsec. This resolution is determined by the spectral width of the superluminescent diode and the noncollinear excitation beam configuration of the system.