Add a phase parameter to frequency-domain monitor data.

[e-g-melo]

Is your feature request related to a problem? Please describe.
In our meetings with professors interested in the teaching program, they frequently ask how to create field animations using Tidy3d.

Describe the solution you'd like
Currently, we have the FieldTimeMonitor, which allows us to create time-domain animations easily. However, animating the frequency-domain fields would be nice and less memory-intensive for teaching purposes. For example, to show how the waves propagate from a point-dipole source, we could animate the field phase, like below:

Describe alternatives you've considered
It is possible to get the field components from the FieldData object, change the phase, and create an animation. However, a built-in feature would help Tidy3D beginners.

Additional context
Other field animation example from mode data:

[momchil-flex]

I am a bit confused by the title of this issue vs. what it's asking for. Are you suggesting a convenience method to create the entire animation, like a FieldData.animate(...)? Or what do you mean by "add a phase parameter"?

[momchil-flex]

Assigning @tylerflex so that someone is on this, but feel free to reassign if you want.

[e-g-melo]

Both should work for the purpose of creating the animations, but I think adding the phase parameter would be more general, allowing the user to choose how to create the animations or plot a single field snapshot using a different phase.

[tylerflex]

@e-g-melo could you explain what the API should look like for adding a phase parameter? like

field_data = field_data.apply_phase(phase)

or something directly stored in the field data? like FieldData(..., phase=1.0) that we can modify with updated_copy()?

[e-g-melo]

We could include a phase parameter in the plot_field function for both FDTD and ModeSolver data, like below:

sim_data.plot_field("field", "Ex", "real", y=0.0, f=200e12, eps_alpha=0.2, phase=phase)

mode_solver.plot_field("Ex", "real", mode_index=0, f=freq0, ax=ax, phase=phase)

And include a function like the apply_phase(phase) as well to allow for custom plots or whatever the user wants to do.

mode_data_1 = mode_data.apply_phase(phase)
mode_data_1.Ex.isel(mode_index=0, f=freq0)).real.plot(x="x", y="z", ax=ax, cmap="RdBu")

field_data_1 = field_data.apply_phase(phase)
Ez_data = field_data_1.Ez.isel(y=0).interp(f=freq0)
Ez_data.real.plot(x="x", y="z", cmap="bwr", ax=ax)

[tylerflex]

@e-g-melo I made a solution here, please give it a test when you get a chance thanks.
#1271

[e-g-melo]

Wow! That was fast!

I will try it. Thanks!

[tylerflex]

actually need to fix one thing, give me a sec

[tylerflex]

should be working now

[tylerflex]

Fixed by #1271