wpg.optical_elements module

This module contains definitions custom optical elements.

Described mapping (or aliases) of some of SRW optical elements (SRWLOpt* <-> wpg)

wpg.optical_elements.Aperture(shape, ap_or_ob, Dx, Dy=1e+23, x=0, y=0)

Defining an aperture/obstacle propagator: A wrapper to a SRWL function SRWLOptA()

Parameters:

• shape – ‘r’ for rectangular, ‘c’ for circular
• ap_or_ob – ‘a’ for aperture, ‘o’ for obstacle
• Dy (Dx,) – transverse dimensions [m]; in case of circular aperture, only Dx is used for diameter
• y (x,) – transverse coordinates of center [m]

Returns:

opAp - aperture propagator, struct SRWLOptA

wpg.optical_elements.CRL(_foc_plane, _delta, _atten_len, _shape, _apert_h, _apert_v, _r_min, _n, _wall_thick, _xc, _yc, _void_cen_rad=None, _e_start=0, _e_fin=0, _nx=1001, _ny=1001)

Setup Transmission type Optical Element which simulates Compound Refractive Lens (CRL).

Parameters:

• _foc_plane – plane of focusing: 1- horizontal, 2- vertical, 3- both
• _delta – refractive index decrement (can be one number of array vs photon energy)
• _atten_len – attenuation length [m] (can be one number of array vs photon energy)
• _shape – 1- parabolic, 2- circular (spherical)
• _apert_h – horizontal aperture size [m]
• _apert_v – vertical aperture size [m]
• _r_min – radius (on tip of parabola for parabolic shape) [m]
• _n – number of lenses (/”holes”)
• _wall_thick – min. wall thickness between “holes” [m]
• _xc – horizontal coordinate of center [m]
• _yc – vertical coordinate of center [m]
• _void_cen_rad – flat array/list of void center coordinates and radii: [x1, y1, r1, x2, y2, r2,…]
• _e_start – initial photon energy
• _e_fin – final photon energy

Returns:

transmission (SRWLOptT) type optical element which simulates CRL

class wpg.optical_elements.Empty

Bases: wpg.optical_elements.WPGOpticalElement

Optical element: Empty. This is empty propagator used for sampling and zooming wavefront

propagate(wfr, propagation_parameters)

Propagate wavefront through empty propagator, used for sampling and resizing wavefront

wpg.optical_elements.Mirror_elliptical(orient, p, q, thetaE, theta0, length)

Defining a plane elliptical focusing mirror propagator: A wrapper to a SRWL function SRWLOptMirEl()

Parameters:

• orient – mirror orientation, ‘x’ (horizontal) or ‘y’ (vertical)
• p – distance to one ellipsis center (source), [m]
• q – distance to the other ellipsis center (focus), [m]
• thetaE – design incidence angle in the center of mirror, [rad]
• theta0 – “real” incidence angle in the center of mirror, [rad]
• length – mirror length, [m]

Returns:

opEFM - elliptical mirror propagator, struct SRWLOptMirEl

wpg.optical_elements.Mirror_plane(orient, theta, length, range_xy, filename, scale=1, delim='\t')

Defining a plane mirror propagator with taking into account surface height errors

Parameters:

• orient – mirror orientation, ‘x’ (horizontal) or ‘y’ (vertical)
• theta – incidence angle [rad]
• length – mirror length, [m]

Range_xy:

range in which the incident WF defined [m]

Filename:

full file name with mirror profile of two columns, x and h(x) - heigh errors [m]

Scale:

scale factor, optical path difference OPD = 2*h*scale*sin(theta)

Delim:

delimiter between data columns

Returns:

opIPM - imperfect plane mirror propagator

class wpg.optical_elements.Use_PP(auto_resize_before=None, auto_resize_after=None, releative_precision=None, semi_analytical_treatment=None, fft_resizing=None, zoom=None, zoom_h=None, zoom_v=None, sampling=None, sampling_h=None, sampling_v=None, srw_pp=None)

Bases: object

Short version of propagation parameters. Should be used with wpg.beamline.Beamline

Params srw_pp:propagation parameters in srw style

auto_resize_after

Auto-Resize (1) or not (0) After propagation

auto_resize_before

Auto-Resize (1) or not (0) Before propagation

fft_resizing

Do any Resizing on Fourier side, using FFT, (1) or not (0)

get_srw_pp()

Return SRW propagation parameters list. Useful for interoperations with SRW tools.

Returns:list of floats (propagation parameters)

releative_precision

Relative Precision for propagation with Auto-Resizing (1. is nominal)

sampling

Resolution modification factor at Resizing

sampling_h

Horizontal Resolution modification factor at Resizing

sampling_v

Vertical Resolution modification factor at Resizing

semi_analytical_treatment

Allow (1) or not (0) for semi-analytical treatment of quadratic phase terms at propagation

zoom

Range modification factor at Resizing (1. means no modification)

zoom_h

Horizontal Range modification factor at Resizing (1. means no modification)

zoom_v

Vertical Range modification factor at Resizing

wpg.optical_elements.VLS_grating(_mirSub, _m=1, _grDen=100, _grDen1=0, _grDen2=0, _grDen3=0, _grDen4=0, _grAng=0)

Optical Element: Grating.

param _mirSub: SRWLOptMir (or derived) type object defining substrate of the grating :param _m: output (diffraction) order :param _grDen: groove density [lines/mm] (coefficient a0 in the polynomial groove density: a0 + a1*y + a2*y^2 + a3*y^3 + a4*y^4) :param _grDen1: groove density polynomial coefficient a1 [lines/mm^2] :param _grDen2: groove density polynomial coefficient a2 [lines/mm^3] :param _grDen3: groove density polynomial coefficient a3 [lines/mm^4] :param _grDen4: groove density polynomial coefficient a4 [lines/mm^5] :param _grAng: angle between the grove direction and the saggital direction of the substrate [rad] (by default, groves are made along saggital direction (_grAng=0))

wpg.optical_elements.WF_dist(nx, ny, Dx, Dy)

Create a ‘phase screen’ propagator for wavefront distortions: A wrapper to SRWL struct SRWLOptT

Params nx:number of points in horizontal direction Params ny:number of points in vertical direction Params Dx:size in m Params Dy:size in

class wpg.optical_elements.WPGOpticalElement

Bases: object

Base class for optical elements.

wpg.optical_elements.Xtal(_d_sp=5.4309, _psi0r=-1.446e-05, _psi0i=3.202e-07, _psi_hr=8.8004e-06, _psi_hi=3.0808e-07, _psi_hbr=8.8004e-06, _psi_hbi=3.0808e-07, _tc=0.0001, _ang_as=0)

Optical Element: Crystal.

Parameters:

• _d_sp – (_d_space) crystal reflecting planes d-spacing (John’s dA) [A]
• _psi0r – real part of 0-th Fourier component of crystal polarizability (John’s psi0c.real) (units?)
• _psi0i – imaginary part of 0-th Fourier component of crystal polarizability (John’s psi0c.imag) (units?)
• _psi_hr – (_psiHr) real part of H-th Fourier component of crystal polarizability (John’s psihc.real) (units?)
• _psi_hi – (_psiHi) imaginary part of H-th Fourier component of crystal polarizability (John’s psihc.imag) (units?)
• _psi_hbr – (_psiHBr:) real part of -H-th Fourier component of crystal polarizability (John’s psimhc.real) (units?)
• _psi_hbi – (_psiHBi:) imaginary part of -H-th Fourier component of crystal polarizability (John’s psimhc.imag) (units?)
• _tc – crystal thickness [m] (John’s thicum)
• _ang_as – (_Tasym) asymmetry angle [rad] (John’s alphdg)
• _nvx – horizontal coordinate of outward normal to crystal surface (John’s angles: thdg, chidg, phidg)
• _nvy – vertical coordinate of outward normal to crystal surface (John’s angles: thdg, chidg, phidg)
• _nvz – longitudinal coordinate of outward normal to crystal surface (John’s angles: thdg, chidg, phidg)
• _tvx – horizontal coordinate of central tangential vector (John’s angles: thdg, chidg, phidg)
• _tvy – vertical coordinate of central tangential vector (John’s angles: thdg, chidg, phidg)

wpg.optical_elements.append_Xtal(bl, xtal='C', h=1, k=1, l=1, tc=0.0001, _dE=0.0, doPrint=False)

Append to a beamline Xtal propagator

Parameters:bl – Beamline() structure

wpg.optical_elements.calculateOPD(wf_dist, mdatafile, ncol, delim, Orient, theta, scale=1.0, stretching=1.0)

Calculates optical path difference (OPD) from mirror profile and fills the struct wf_dist (struct SRWLOptT) for wavefront distortions

Params wf_dist:struct SRWLOptT Params mdatafile:  an ascii file with mirror profile data Params ncol:number of columns in the file Params delim:delimiter between numbers in an row, can be space (‘ ‘), tab ‘ ‘, etc Params orient:mirror orientation, ‘x’ (horizontal) or ‘y’ (vertical) Params theta:incidence angle Params scale:scaling factor for the mirror profile Parameters:stretching – scaling factor for the mirror profile x-axis (@TODO a hack, should be removed ASAP)

:return filled

wpg.optical_elements.define_Xtal(xtal='C', h=4, k=0, l=0, tc=0.0001, idx=0, _dE=0.0, doPrint=False)

Parameters:

• xtal – crystal type (now only ‘Si’ and ‘C’ are suppoted)
• h,k,l – Miller indices
• tc – crystal thickness, [m]
• idx – the given photon energy line number in crystal parameters tables (ascii files ‘<xtal>_xih_<hkl>.dat’ and ‘<xtal>_xi0.dat’)
• _dE – photon energy offset, eV
• doPrint – if True additional printouts for crystal orientation matrixes

:return

wpg.optical_elements.Drift

alias of wpg.srwlib.SRWLOptD

wpg.optical_elements.Lens

alias of wpg.srwlib.SRWLOptL

class wpg.optical_elements.Aperture

Defining an aperture/obstacle propagator: A wrapper to a SRWL function SRWLOptA()

Parameters:

• shape – ‘r’ for rectangular, ‘c’ for circular
• ap_or_ob – ‘a’ for aperture, ‘o’ for obstacle
• Dy (Dx,) – transverse dimensions [m]; in case of circular aperture, only Dx is used for diameter
• y (x,) – transverse coordinates of center [m]

Returns:

opAp - aperture propagator, struct SRWLOptA

class wpg.optical_elements.WF_dist

Create a ‘phase screen’ propagator for wavefront distortions: A wrapper to SRWL struct SRWLOptT

Params nx:number of points in horizontal direction Params ny:number of points in vertical direction Params Dx:size in m Params Dy:size in