epsproc.efield package

Submodules

• epsproc.efield.efields module
  • Efield
    • Efield.ECalc()
    • Efield.EFFT()
    • Efield.EiFFT()
    • Efield.FWHMGau()
    • Efield.Gau()
    • Efield.calcSpectrogram()
    • Efield.chirp()
    • Efield.fConv()
    • Efield.finst()
    • Efield.phaseMask()
    • Efield.plot()
    • Efield.plotSpectrogram()
    • Efield.plotSpectrogramHV()
    • Efield.printDef()
    • Efield.removePhase()
    • Efield.setEf()
    • Efield.setPhase()
    • Efield.toXarrayDS()

Module contents

ePSproc electric field functions.

Generate, propagate and model E-fields.

06/05/20 Updated methods, added Xarray conversion & Holoviews plotting - basics only.

27/04/20 Updating & packaging - but still very much a work-in-progress.

20/3/20 Basics developed in tests/methodDev/geometric_method_dev_low-level_E-fields_200320.ipynb

TODO - Integration with EPR and geometric methods code. Need Xarray conversion plus appropriate regridding for this, and proper handling of polarisation terms p. - Tidy up and debug. - Improve spectrogram methods & plotting. - Improve pulse modification methods. - Additional pulse properties, e.g. instantaneous frequency.

class epsproc.efield.Efield(Edef=None, units=None, verbose=True)

Bases: object

Basic class for handling E-field generation, data and related functions.

Currently set for field creation based on Gaussian defined in time-domain. Defaults to a single (E,t) point if no parameters are supplied - this can be used with epsproc.geomFunc.EPR()

Starting to look a bit top-heavy… passing directly to Xarray might save some structural overhead here?

Define Gaussian field in the time-domain, with amplitude $E_0$, width $sigma$ and carrier frequency $omega_0$:

\[ \begin{align}\begin{aligned}E(\omega_0,t)=E_{0}e^{-(t^2/2\sigma^{2})}e^{i\omega_0 t}\\Carrier frequency in rad/s:\end{aligned}\end{align} \]

\[ \begin{align}\begin{aligned}\omega_0 = 2\pi \Omega_0\\FWHM and Gaussian width (see https://en.wikipedia.org/wiki/Gaussian_function for full definitions):\end{aligned}\end{align} \]

\[ \begin{align}\begin{aligned}FWHM = 2\sigma\sqrt{2ln2}\\Parameters ---------- If no parameters are passed, return single point with E0 = 1 For a time-dependent field, pass at least sigma.\\E0 : float, optional, default = None Set (relative) field strength. If None, set E0 = 1\\sigma : float, optional, default = None Set Gaussian width :math:\sigma, where :math:FWHM=2\sigma\sqrt{2ln2}\\t : array, optional, default = None Set time axis for E-field. If None, defaults to np.arange(-(5*sigma), 5*sigma, self.dt), and self.dt = 0.01*sigma\\dt : float, optional, default = None Set time-step. Default will set from t-axis, or self.dt = 0.01*sigma if sigma only passed. Pass here to override.\\l0 : float, optional, default = None Central wavelength in wavelength working units. If supplied this will be used to set f0 and w0.\\f0, w0 : float, optional, default = None Carrier frequency in freq. units, and :math:\omega_0 in (rad/s). If only f0 supplied, w0 will be calculated. If f0 and w0 supplied, w0 will be used directly. If None, this will be ignored.\\units : dictionary, optional, default = None Set units. If not passed, default dict will be created with units (THz, nm, fs) set.\\ TODO: - best way to handle unit conversions? Did some of this for FROG code already? Yes, see python est_codes\E_fields_redux_231118_class.py - Consider other structures here, dataclass or namedtuple? https://stackoverflow.com/questions/354883/how-do-i-return-multiple-values-from-a-function - Xarray conversion? Use Xarray directly in class? - Bug with FFT/iFFT code? If shift=True and ishift=True then get extra freq components on iFFT - must be bug in axis assignment/conversion? OK if shift = False.\end{aligned}\end{align} \]

ECalc()

EFFT()

EiFFT(Emod=None, Ninput=None, comment='')

FWHMGau()

Gau()

calcSpectrogram(signal=None, gate=None, fType='blind', N=None, verbose=False)

chirp(A, resetPhase=False, comment=None)

Add quadratic phase (chirp) in spectral domain. Requires an E-field object, and chirp parameter A.

TODO: check Diels for nomenclature here.

fConv()

Convert freq. domain axis to lenght & energy units. and set fields.

finst()

Calculate f(t) as instantaneous freq.

phaseMask(domain=None, thres=None)

Mask pulse phase away from main features. Should convert to use masked arrays for reversibility, or just return a mask (currently overwrites Ef).

plot(plotType='phaseUW', Nplot=None, domainList=None, thres=0.01)

Basic plot with Matplotlib

plotSpectrogram()

VERY basic spectrogram plotter from old code - for quick testing only.

TODO: fix axes for with/withou fft shift.

BETTER: use plotSpectrogramHV() instead, this uses full axes as set.

plotSpectrogramHV(N=None)

printDef()

removePhase(domain=None)

Remove imaginary field terms (reset phase).

setEf()

Calculate pulse properties and E-fields based on Edef.

setPhase(phaseVec=None, domain=None)

Set imaginary field terms (set phase) for specified domain & recalculated FFT.

toXarrayDS(N=None)