Grating#

class furst.gratings.Grating(name='grating', sag=None, radius=<Quantity 0. mm>, width_clear=<Quantity 0. mm>, width_mech=<Quantity 0. mm>, material=None, rulings=None, rowland_radius=<Quantity 0. mm>, rowland_azimuth=<Quantity 0. deg>, translation=<Quantity 0. mm>, pitch=<Quantity 0. deg>, yaw=<Quantity 0. deg>, roll=<Quantity 0. deg>)[source]#

Bases: Rollable, Yawable, Pitchable, Translatable, AbstractRowlandComponent, Generic[SagT, MaterialT, RulingT]

A model of the FURST diffraction grating.

This is a concave, spherical diffraction grating a rectangular aperture.

Examples

Plot an exaggerated grating on the Rowland circle.

import numpy as np
import matplotlib.pyplot as plt
import astropy.units as u
import astropy.visualization
import named_arrays as na
import optika
import furst

# Define the Rowland circle
rowland_radius = 1000 * u.mm
a = na.linspace(0, 360, axis="angle", num=1001) * u.deg
rowland_circle = rowland_radius * na.Cartesian3dVectorArray(
    x=np.sin(a),
    z=np.cos(a),
)

# Define the grating model
grating = furst.gratings.Grating(
    sag=optika.sags.SphericalSag(
        radius=-2 * rowland_radius,
    ),
    width_clear=na.Cartesian2dVectorArray(
        x=1000 * u.mm,
        y=20 * u.mm,
    ),
    material=optika.materials.Mirror(),
    rowland_radius=rowland_radius,
    rowland_azimuth=175 * u.deg,
)

# Plot the grating surface and the Rowland circle
with astropy.visualization.quantity_support():
    fig, ax = plt.subplots()
    grating.surface.plot(
        ax=ax,
        components=("z", "x"),
        color="tab:blue",
    )
    na.plt.plot(
        rowland_circle,
        ax=ax,
        components=("z", "x"),
        color="black",
        linestyle="dashed",
        zorder=-10,
    )
    ax.set_aspect("equal")

../_images/furst.gratings.Grating_0_0.png

Attributes

`material`	The coating material used to make the optic reflective in the target spectral range.
`name`	The human-readable name of this optic.
`pitch`	The angle of rotation about the vector tangent to the Rowland circle.
`radius`	The radius of curvature of the optical surface.
`roll`	The angle of rotation about the vector normal to the Rowland circle.
`rowland_azimuth`	The azimuth of the virtual image of the Sun on the Rowland circle, relative to the optic axis of the instrument.
`rowland_radius`	The distance from the center of the Rowland circle to the virtual image of the Sun within the feed optic.
`rulings`	A model of the grating ruling spacing and profile.
`sag`	The sag profile of the grating surface.
`surface`	Convert this object into an instance of `optika.surfaces.AbstractSurface`.
`transformation`	the coordinate transformation between the global coordinate system and this object's local coordinate system
`translation`	Physical offset from the optic's nominal position on the Rowland circle.
`width_clear`	The height and width of the clear aperture of the grating.
`width_mech`	The height and width of the grating substrate.
`yaw`	The angle of rotation about the axis of symmetry of the feed optic.

Methods

`__init__`([name, sag, radius, width_clear, ...])
`to_string`([prefix])	Public-facing version of the `__repr__` method that allows for defining a prefix string, which can be used to calculate how much whitespace to add to the beginning of each line of the result.

Inheritance Diagram

Parameters:

name (str)
sag (SagT)
radius (Quantity | AbstractScalar)
width_clear (Quantity | AbstractCartesian2dVectorArray)
width_mech (Quantity | AbstractCartesian2dVectorArray)
material (MaterialT)
rulings (RulingT)
rowland_radius (Quantity | AbstractScalar)
rowland_azimuth (Quantity | AbstractScalar)
translation (Quantity | AbstractCartesian3dVectorArray)
pitch (Quantity | AbstractScalar)
yaw (Quantity | AbstractScalar)
roll (Quantity | AbstractScalar)

to_string(prefix=None)#

Public-facing version of the __repr__ method that allows for defining a prefix string, which can be used to calculate how much whitespace to add to the beginning of each line of the result.

Parameters:: prefix (None | str) – an optional string, the length of which is used to calculate how much whitespace to add to the result.
Return type:: str

material: MaterialT = None#: The coating material used to make the optic reflective in the target spectral range.

name: str = 'grating'#: The human-readable name of this optic.

pitch: Quantity | AbstractScalar = <Quantity 0. deg>#: The angle of rotation about the vector tangent to the Rowland circle.

radius: Quantity | AbstractScalar = <Quantity 0. mm>#: The radius of curvature of the optical surface.

roll: Quantity | AbstractScalar = <Quantity 0. deg>#: The angle of rotation about the vector normal to the Rowland circle.

rowland_azimuth: Quantity | AbstractScalar = <Quantity 0. deg>#: The azimuth of the virtual image of the Sun on the Rowland circle, relative to the optic axis of the instrument.

rowland_radius: Quantity | AbstractScalar = <Quantity 0. mm>#: The distance from the center of the Rowland circle to the virtual image of the Sun within the feed optic.

rulings: RulingT = None#: A model of the grating ruling spacing and profile.

sag: SagT = None#: The sag profile of the grating surface.

property surface: Surface#: Convert this object into an instance of optika.surfaces.AbstractSurface.

property transformation: AbstractTransformation#: the coordinate transformation between the global coordinate system and this object’s local coordinate system

translation: Quantity | AbstractCartesian3dVectorArray = <Quantity 0. mm>#: Physical offset from the optic’s nominal position on the Rowland circle.

width_clear: Quantity | AbstractCartesian2dVectorArray = <Quantity 0. mm>#: The height and width of the clear aperture of the grating.

width_mech: Quantity | AbstractCartesian2dVectorArray = <Quantity 0. mm>#: The height and width of the grating substrate.

yaw: Quantity | AbstractScalar = <Quantity 0. deg>#: The angle of rotation about the axis of symmetry of the feed optic.

Grating#

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