Aerosol Complex Refractive indices m=p-iq
H2SO4/H2O solutions
T=293 K (assumed)

 
Real and imaginary refractive indices 
# entries
Spectral range (micron)
Concentration (%)*
  184 
6.365 - 13.382
75.0
 211
 6.381 - 13.369 
90.0

 
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Reference: 

Remsberg E.E., Lavery D., and Crawford B., "Optical constants for sulfuric and nitric acids", J.Chem. and Engin. Data, 19, 263-255 (1974)