coating_witness_fit

furst.feed_optics.materials.coating_witness_fit()

A coating fitted to the coating_witness_measured() measurement.

Examples

Plot the fitted vs. measured reflectivity of the feed optic witness sample.

import numpy as np
import matplotlib.pyplot as plt
import named_arrays as na
import optika
from furst import feed_optics

# Load the measured reflectivity of the witness sample
multilayer_measured = feed_optics.materials.coating_witness_measured()
measurement = multilayer_measured.efficiency_measured

# Isolate the angle of incidence of the measurement
angle_incidence = measurement.inputs.direction

# Fit a MgF2+Al coating to the measured reflectivity
coating = feed_optics.materials.coating_witness_fit()

# Define the rays incident on the coating that will be used to
# compute the reflectivity
rays = optika.rays.RayVectorArray(
    wavelength=measurement.inputs.wavelength,
    direction=na.Cartesian3dVectorArray(
        x=np.sin(angle_incidence),
        y=0,
        z=np.cos(angle_incidence),
    ),
)

# Compute the reflectivity of the fitted multilayer stack
reflectivity_fit = coating.efficiency(
    rays=rays,
    normal=na.Cartesian3dVectorArray(0, 0, -1),
)

# Plot the fitted vs. measured reflectivity
fig, ax = plt.subplots(constrained_layout=True)
na.plt.scatter(
    measurement.inputs.wavelength,
    measurement.outputs,
    ax=ax,
    label="measured"
);
na.plt.plot(
    rays.wavelength,
    reflectivity_fit,
    ax=ax,
    label="fitted",
    color="tab:orange",
);
ax.set_xlabel(f"wavelength ({rays.wavelength.unit:latex_inline})")
ax.set_ylabel("reflectivity")
ax.legend();

# Print the fitted coating
coating

MultilayerMirror(
    layers=[
        Layer(
            chemical='MgF2',
            thickness=25.12932588 nm,
            interface=ErfInterfaceProfile(
                width=3.44864186 nm,
            ),
            kwargs_plot={'color': 'tab:blue', 'alpha': 0.3},
            x_label=None,
        ),
        Layer(
            chemical='Al',
            thickness=59.98390658 nm,
            interface=ErfInterfaceProfile(
                width=3.44864186 nm,
            ),
            kwargs_plot={'color': 'tab:blue', 'alpha': 0.5},
            x_label=None,
        ),
    ],
    substrate=Layer(
        chemical='SiO2',
        thickness=3. mm,
        interface=ErfInterfaceProfile(
            width=3.44864186 nm,
        ),
        kwargs_plot={'color': 'gray', 'alpha': 0.5},
        x_label=None,
    ),
)

Return type:

MultilayerMirror