Measurement of the Phonon Decoherence in Diamond Using Spectral Interference of Stokes Emission

In this paper, we measure the decoherence time of phonons using spectral interference of the Stokes emission of diamond. Two 100 femtosecond laser pulses, separated by a delay tau, are sent through a polished diamond sample of 1.2 mm thickness. Optical phonons in the Brillouin zone centre are created by Raman scattering from the ultrafast laser pulses and can be heralded by the Stokes photons emitted, whose superposed spectrum is recorded by a spectrometer.