Nomenclature
Abbreviations
OL	Optical limiting
CNTs	Carbon Nanotubes
SWCNHs	Single Walled Carbon Nanohorns
SDS	Sodium Dodecyl Sulphate
NH1, NH2, NH3, NH4, NH5, NH6, OX, B80nm, D80nm	Sample labels (explanations in Table 1)
UV–VIS	Ultraviolet–Visible
UV	Ultraviolet
DLS	Dynamic Light Scattering
ESA	Excited State Absorption
SEM	Scanning Electron Microscope
TEM	Transmission Electron Microscope
XRD	X-ray Diffraction
NL-LB	Nonlinear Lambert–Beer
MMJ	McEwan–Milsom–James
Symbols
E	Energy
F	Energy fluence
T	Relative transmittance
$ħ$	Reduced Planck constant
ω	Angular speed of the electromagnetic wave
z	Position in the sample
α	Linear extinction coefficient
σ 1	Excited State Absorption cross section
Ts 2	Fitting coefficient (see text for explanation)
L	Sample thickness
αe	Nonlinear extinction coefficient
S	S = Σi (observed Eout, i − computed Eout, i)2, see text for explanation
A	Laser spot area
Subscripts
in	input
out	output
m	minimum
t	threshold