Hi,

I got some problems with units and normalization with the radial grating:

Lets say my grating equation is d = 1872-9459r^1+23000r^2+…where the units are in microns.

How do I insert it with the correct units to the radial graitng parameters?

edit:

I try also grating equation with d = 0.41-3.21*r^1+12.53*r^2+...in milimeters where this series is very similiar to ~1/r, still, something is wrong...

Thanks,

Nadav

Hi David,

Thanks for the quick and the detailed answer.

 I tried now to insert the following series: d = 1.7e2-2.97r+2.12e-2*r^2-7.7e-5*r^3+1.56e-7 *r^4-1.86e-10 *r^5+1.29e-13*r^6-4.8e-17*r^7+7.41e-21*r^8(in mircrons red in the graph)  and no matter what was the Normalziation, the grating did almost nothing. 

edit: well, it’s seems to work now.  

Thanks again,

Nadav

Hi Nadav,

When I use your equation, I get the following graph:

I’m assuming OpticStudio won’t like a negative grating spacing (d value), which is happening at about 270 um.

I’m using the following code to produce the graph:

import numpy as np
import matplotlib.pyplot as plt

# Coefficients
As = [1.7e2, -2.97, 2.12e-2, -7.7e-5, 1.56e-7, -1.86e-10, 1.29e-13, -4.8e-17, 7.41e-21]

# Grid [um]
r = np.linspace(0, 1500, 100)

# Grating spacing
d = 0

for (power, A) in enumerate(As):
    d += A * r ** power


# Plot the results
plt.figure()
plt.plot(r, d)
plt.xlabel('r [um]')
plt.ylabel('d [um]')
plt.grid()
plt.show()

This seems quite different to what you are showing, are you sure about the coefficients?

Take care,

David

Hi David,

Maybe I did mistake while copying.

Add here a new polynom that worked[ 3.47068643e-23 -2.42712129e-19  7.17714256e-16 -1.16904982e-12
  1.14551793e-09 -6.92639738e-07  2.54963018e-04 -5.39725456e-02
  6.01267046e+00]-starting with A8 and ending with A0. Now it seems to work, but I think I have now problem with our model and not with zemax. I’ll update in case I stuck again.

Thanks again for the help David,

Nadav

Hi Nadav,

My pleasure. The graph looks better with those coefficients indeed.

 Let us know if you are stuck again :)

Take care,

David