AnalyticOpticalElement

class poppy.AnalyticOpticalElement(shift_x=None, shift_y=None, rotation=None, inclination_x=None, inclination_y=None, **kwargs)

Bases: poppy.poppy_core.OpticalElement

Defines an abstract analytic optical element, i.e. one definable by some formula rather than by an input OPD or pupil file.

This class is useless on its own; instead use its various subclasses that implement appropriate get_opd and/or get_transmission functions. It exists mostly to provide some behaviors & initialization common to all analytic optical elements.

name, verbose, oversample, planetype : various

Same as for OpticalElement

transmission, opd : string

These are not allowed for Analytic optical elements, and this class will raise an error if you try to set one.

shift_x, shift_y : Optional floats

Translations of this optic, given in meters relative to the optical axis for pupil plane elements, or arcseconds relative to the optical axis for image plane elements.

rotation : Optional float

Rotation of the optic around its center, given in degrees counterclockwise. Note that if you apply both shift and rotation, the optic rotates around its own center, rather than the optical axis.

Attributes Summary

shape

Return shape of the OpticalElement, as a tuple

Methods Summary

get_coordinates(wave)	Get coordinates of this optic, optionally including shifts
get_opd(wave)	Return the optical path difference, given a wavelength.
get_phasor(wave)	Compute a complex phasor from an OPD, given a wavelength.
get_transmission(wave)	Note that this is the amplitude transmission, not the total intensity transmission.
sample([wavelength, npix, grid_size, what, …])	Sample the Analytic Optic onto a grid and return the array
to_fits([outname, what, wavelength, npix])	Save an analytic optic computed onto a grid to a FITS file

Attributes Documentation

shape

Return shape of the OpticalElement, as a tuple

Methods Documentation

get_coordinates(wave)

Get coordinates of this optic, optionally including shifts

Method: Calls the supplied wave object’s coordinates() method, then checks for the existence of the following attributes: “shift_x”, “shift_y”, “rotation”, “inclination_x”, “inclination_y” If any of them are present, then the coordinates are modified accordingly.

Shifts are given in meters for pupil optics and arcseconds for image optics. Rotations and inclinations are given in degrees.

For multiple transformations, the order of operations is:

shift, rotate, incline.

get_opd(wave)

Return the optical path difference, given a wavelength.

wave : float or obj

either a scalar wavelength or a Wavefront object

ndarray giving OPD in meters

get_phasor(wave)

Compute a complex phasor from an OPD, given a wavelength.

The returned value should be the complex phasor array as appropriate for multiplying by the wavefront amplitude.

wave : float or obj

either a scalar wavelength or a Wavefront object

get_transmission(wave)

Note that this is the amplitude transmission, not the total intensity transmission.

sample(wavelength=<Quantity 1.e-06 m>, npix=512, grid_size=None, what='amplitude', return_scale=False, phase_unit='waves')

Sample the Analytic Optic onto a grid and return the array

wavelength : astropy.units.Quantity or float

Wavelength (in meters if unit not given explicitly)

npix : integer

Number of pixels for sampling the array

grid_size : float

Field of view grid size (diameter) for sampling the optic, in meters for pupil plane optics and arcseconds for image planes. Default value is taken from the optic’s properties, if defined. Otherwise defaults to 6.5 meters or 2 arcseconds depending on plane.

what : string

What to return: optic ‘amplitude’ transmission, ‘intensity’ transmission, ‘phase’, or ‘opd’. Note that optical path difference, OPD, is given in meters.

phase_unit : string

Unit for returned phase array IF what==’phase’. One of ‘radians’, ‘waves’, ‘meters’. (‘meters’ option is deprecated; use what=’opd’ instead.)

return_scale : float

if True, will return a tuple containing the desired array and a float giving the pixel scale.

to_fits(outname=None, what='amplitude', wavelength=<Quantity 1.e-06 m>, npix=512, **kwargs)

Save an analytic optic computed onto a grid to a FITS file

The FITS file is returned to the calling function, and may optionally be saved directly to disk.

what : string

What quantity to save. See the sample function of this class

wavelength : float

Wavelength in meters.

npix : integer

Number of pixels.

outname : string, optional

Filename to write out a FITS file to disk

See the sample() function for additional optional parameters.