add phase to all laser implementations

[PrometheusPi]

This pull request adds a phase to all laser implementation thus allowing to run simulations suggested by @ssstuvz.

ToDo:
check if setting phase works for:

• laserGaussianBeam
• laserPlaneWave
• laserPolynom
• laserPulseFrontTilt
• laserWavepacket

@ax3l:
This pull request adjusts:

• laserConfig.unitless
• laserConfig.param

and thus needs an entry to the CHANGELOG.md after it is merged to master.

[ax3l]

if it does not have a unit, do not "fake convert" it. -> no entry necessary.

[ax3l]

@PrometheusPi suggested a better refactoring to add a general support where and how to define the phase of a laser.

[ax3l]

@PrometheusPi close as outdated for now? If I remember correctly, you wanted to give it a fresh start.

[PrometheusPi]

We can close or keep it. I will overwrite the last commits anyway. Keep it, so I have a more urgent reminder 😁

[ax3l]

ok, fine with me :)
just re-assign me when there is something to do.

[PrometheusPi]

added an implementation for all lasers

[ax3l]

added wait-4-author label since todo check if it is working as expected is still open :)

[ax3l]

shouldn't that be a += ?
you are going to overwrite the input parameter by that (even if it is zero by default).

[PrometheusPi]

Yes, I did this on purpose to avoid any conflict wheter one should set the pase in laserConfig.param or in the laser implementation.

Why do we use this reference approach anyways?

I thought wait-4-author/WIP is only needed if it is not obvious that you still need feedback. (Checklist still not complete was obvious enough for me.) 😄

[PrometheusPi]

Tests were successful:

I used the PIConGPU example LaserWakefield with no particles to simulate all lasers.
It is a 3D (192,1024,192) simulation with LASER_PHASE beeing 0and 3.1415 for all lasers with otherwise default setup.
The Field shown is f["/data/{}/fields/FieldE/x".format(timestep)][96,:,96].

laserGaussianBeam:

laserPlaneWave:

laserPolynom:

laserPulseFrontTilt:

laserWavepacket:

[ax3l]

since LASER_PHASE is already float_X that line should be

phase += float_X(w * runTime) + LASER_PHASE;

[PrometheusPi]

True, I will fix that.

[ax3l]

btw: tests look good, well done! 👍

[PrometheusPi]

I will remove wait for autor/WIP and set wait for assignee/WIP 😝