High‐order Stokes and anti‐Stokes Raman generation in monoisotopic CVD 12C‐diamond

We determined, for the first time, the room temperature phonon energy related to the F-2g vibration mode (omega(SRS(12C)) similar to 1333.2 cm(-1)) in a mono-crystalline single-isotope CVD C-12-diamond crystal by means of stimulated Raman scattering (SRS) spectroscopy. Picosecond one-micron excitation using a Nd3+:Y3Al5O12-laser generates a nearly two-octave spanning SRS frequency comb (similar to 12000 cm(-1)) consisting of higher-order Stokes and anti-Stokes components. The spacing of the spectral lines was found to differ by Delta omega(SRS) similar to 0.9 cm(-1) from the comb spacing (omega(SRS)(natC) similar to 1332.3 cm(-1)) when pumping a conventional CVD diamond crystal with a natural composition of the two stable carbon isotopes C-12 (98.93%) and C-13 (1.07%). (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim