Broadband coherent anti-Stokes Raman scattering (BCARS) is an advanced Raman
spectroscopy method that combines the spectral sensitivity of spontaneous Raman
scattering (SR) with the increased signal intensity of single-frequency
coherent Raman techniques. These two features make BCARS particularly suitable
for ultra-fast imaging of heterogeneous samples, as already shown in
biomedicine. Recent studies demonstrated that BCARS also shows exceptional
spectroscopic capabilities when inspecting crystalline materials like lithium
niobate and lithium tantalate, and can be used for fast imaging of
ferroelectric domain walls. These results strongly suggest the extension of
BCARS towards new imaging applications like mapping defects, strain, or dopant
levels, similar to standard SR imaging. Despite these advantages, BCARS suffers
from a spurious and chemically unspecific non-resonant background (NRB) that
distorts and shifts the Raman peaks. Post-processing numerical algorithms are
then used to remove the NRB and to obtain spectra comparable to SR results.
Here, we show the reproducibility of BCARS by conducting an internal Round
Robin with two different BCARS experimental setups, comparing the results on
different crystalline materials of increasing structural complexity: diamond,
6H-SiC, KDP, and KTP. First, we compare the detected and phase-retrieved
signals, the setup-specific NRB-removal steps, and the mode assignment.
Subsequently, we demonstrate the versatility of BCARS by showcasing how the
selection of pump wavelength, pulse width, and detection geometry can be
tailored to suit the specific objectives of the experiment. Finally, we compare
and optimize measurement parameters for the high-speed, hyperspectral imaging
of ferroelectric domain walls in lithium niobate.Comment: 12 pages, 8 figure