In recent years, hexagonal boron nitride
nanosheets (h-BNNs) have gained attention due to their outstanding
optical properties. However, researchers have yet to extensively
investigate the nonlinear optical (NLO) properties of such new
materials. In the present study, NLO properties of h-BNNs were
investigated for the first time, to the best of our knowledge,
utilizing the Z-scan approach irradiating with 100 fs laser
pulses using different excitation wavelengths that vary from 740 to
820 nm at a constant excitation average power of 1 W.
The investigated 2D nanomaterial (h-BNNs) was created using mechanical
exfoliation, an effective and straightforward approach of producing
h-BNNs. The morphology and crystal structure of the samples have been
investigated using different techniques, including UV-Vis
spectroscopy, transmission electron microscopy, and Raman
spectroscopy. The measurements of nonlinearity show that, by
increasing the excitation wavelength, the nonlinear absorption
coefficient decreases in a linear trend. The as-prepared h-BNNs
performed fascinating optical limiting with a reverse saturable
behavior. This innovative optical nanomaterial makes them promising
sensitive optical components in laser protection applications.