'gaussian_mode' is not defined about hcipy HOT 8 CLOSED

I did a quick look through git history. It seems that this function got accidentally removed three years ago during a refactor. I'll work on this today, and fix some other issues with that part of the code base (it looks very outdated).

from hcipy.

That part of the code base was developed early on when we wanted to do photometry with a single-mode fiber. This part of the code is almost never used. I actually think we might want to rethink the fiber detectors. I think they are a bit awkward to work with and they do not represent actual optical systems. It is probably better to replace them with an simplified single mode fiber optic and a normal detector class.

from hcipy.

Btw @sylacour if you need to make a gaussian mode you can use newer code. We have implemented square and circular Gaussian mode basis (Guassian Hermite and Gaussian Laguerre) https://docs.hcipy.org/dev/api/hcipy.mode_basis.gaussian_hermite.html#hcipy.mode_basis.gaussian_hermite . The typical Gaussian mode is the fundamental mode for both basis sets. E.g. you could create it by using:

gaussian = hcipy.mode_basis.gaussian_hermite(0, 0, mode_field_diameter=mfd, grid=evaluation_grid)

from hcipy.

from hcipy.

So you want access to the complex mode coefficient of the Gaussian mode?

from hcipy.

@syhaffert

It is probably better to replace them with an simplified single mode fiber optic and a normal detector class.

I'm underway with exactly this. A pull request will appear soon (= today). The single mode fiber will be an optical element, with the outgoing wavefront just a complex amplitude.

from hcipy.

from hcipy.

As soon as #192 gets approved, you should be able to do something like:

from hcipy import *
import numpy as np
import matplotlib.pyplot as plt

mode_field_diameter = 1.5  # mode field diameter of the fiber in units of your focal grid
fiber_position = [5, 0]  # position of the fiber in units of your focal grid

fiber_mode = make_gaussian_fiber_mode(mode_field_diameter)

pupil_grid = make_pupil_grid(512)
focal_grid = make_focal_grid(16, mode_field_diameter * 2).shifted(fiber_position)
prop = FraunhoferPropagator(pupil_grid, focal_grid)

aperture = make_circular_aperture(1)(pupil_grid)
wf = Wavefront(aperture)
wf.total_power = 1

smf = SingleModeFiberInjection(focal_grid, fiber_mode, fiber_position)

img = prop(wf)  # focal-plane wavefront
fiber_output = smf(img)
complex_amplitude = fiber_output.electric_field[0]
coupling_percentage = fiber_output.total_power * 100

plt.suptitle(f'{complex_amplitude=:.2g}; {coupling_percentage=:.2g}%')
plt.subplot(1,2,1)
plt.title('Input electric field')
imshow_field(img.electric_field)
plt.subplot(1,2,2)
plt.title('Fiber mode')
imshow_field(smf.mode)
plt.show()

Output:

from hcipy.