Subpicosecond accumulated photon echoes using a continuous-wave multimode diode laser

Subpicosecond accumulated photon echoes have been observed in 1,3,3,1',3',3'-hexamethyl-2,2'-indotricarbocyanine iodide embedded in polyvinyl alcohol at 10 K by using a cw multimode diode laser. The temporal resolution of this measurement is determined by the width of the overall spectral envelope of the diode laser. The dephasing time of 40 psec derived by the echo decay curve is in good agreement with the persistent hole width.