Two-Photon Excited Luminescence of NV-Centers and Stimulated Raman Scattering in Nanodiamonds

In this study, zero-phonon line (ZPL) at 638 nm associated with multiphoton excited negatively-charged single nitrogen-vacancy (NV)-center luminescence is registered in ethanol suspension of submicrometer diamond particles obtained at high pressures and high temperatures (HPHT). Simultaneously Stokes and anti-Stokes components of the stimulated Raman scattering (SRS) in the same sample is registered with a frequency shift of 1332 cm−1 corresponding to the fundamental optical mode of the diamond crystal. We observe anti-Stokes component intensity enhancement caused by its wavelength coincidence with the wavelength of luminescence caused by negatively-charged single nitrogen-vacancy (NV) centers.