GaAs Papatryfonos material fit.

[mariusCZ]

Hi everyone. I am trying to get a Lorentzian material fit for the GaAs Papatryfonos complex refractive index. It can be found here.. The fit generally is not too bad, however I need for the fit to reach zero after that sudden decrease at 850 nm. I am using the example script provided for fitting material data.

I have tried changing the amount of Lorentzians, interpolating the data and taking a limited window of data to try and get the fit as close to zero as possible, however, I cannot quite get there. Here is one example with 15 Lorentzian and data interpolated to a 1000 points.

Here is another example of a window between 800 to 1000 nm also with interpolated data and 15 Lorentzians.

I realise that the sharp downturn is an unusual shape rather than an exponential and so it is hard to fit, but is there anything that can be done to get it closer? Thank you!