Measurement of photon echoes by use of femtosecond Fourier-transform spectral interferometry Likforman, J. -P. ; Joffre, M. ; Thierry-Mieg, V. Abstract Publication: Optics Letters Pub Date: July 1997 DOI: 10.1364/OL.22.001104 Bibcode: 1997OptL...22.1104L