Hi, my friend and I are trying to obtain metal film thickness and dielectric constant through Fresnel equation based on surface plasmon resonance (SPR) experiment. The parameters that we got from experiment are the incident angle and reflectance. We used the curve fitting apps on MatLab. For the first approachment we got the result “Complex value computed by model function, fitting cannot continue. Try using or tightening upper and lower bounds on coefficients”. Then, we change the lower bounds and we got “NaN computed by model function, fitting cannot continue. Try using or tightening upper and lower bounds on coefficients”. Anyone in here has any suggestions about our problem? Thank you.
