finesse.components.surface module

class finesse.components.surface.Surface(*args, **kwargs)[source]

Bases: Connector, MapAndKNMOptic

Abstract optical surface interface providing an object with common properties for finesse.components.mirror.Mirror and finesse.components.beamsplitter.Beamsplitter to inherit from.

Parameters

namestr: Name of newly created surface.
Rfloat, optional: Reflectivity of the surface.
Tfloat, optional: Transmissivity of the surface.
Lfloat, optional: Loss of the surface.
phifloat, optional: Microscopic tuning of the surface (in degrees).
Rcfloat, optional: Radius of curvature (in metres); defaults to numpy.inf to indicate a planar surface. An astigmatic surface can be set with Rc = (Rcx, Rcy).

property L: L : float, optional Loss of the surface.

property R: R : float, optional Reflectivity of the surface.

property Rc[source]

The radius of curvature of the mirror in metres, for both the tangential and sagittal planes.

Getter:: Returns values of both planes’ radii of curvature as a numpy.ndarray where the first element is the tangential plane RoC and the second element is the sagittal plane RoC.
Setter:: Sets the radius of curvature.

Examples

The following sets the radii of curvature of an object m, which is a sub-instance of Surface, in both directions to 2.5 m:

>>> m.Rc = 2.5

Whilst this would set the radius of curvature in the x-direction (tangential plane) to 2.5 m and the radius of curvature in the y-direction (sagittal plane) to 2.7 m:

>>> m.Rc = (2.5, 2.7)

property Rcx: Radius of curvature (x)

property Rcy: Radius of curvature (y)

property T: T : float, optional Transmissivity of the surface.

actuate_roc(dioptres, direction=('x', 'y'))[source]

Actuate on the radius of curvature (RoC) of the surface with a specified dioptre shift.

Sets the RoC to a new value, \(R_2\), via,

\[R_2 = \frac{2}{d + \frac{2}{R_1}},\]

where \(R_1\) is the current RoC and \(d\) is the dioptre shift (i.e. the dioptre argument).

By default, both planes of curvature are shifted. To shift, e.g., only the tangential plane, specify direction="x".

Parameters

dioptresfloat: Shift in surface RoC in dioptres.
directiontuple or str, optional; default: (“x”, “y”): RoC plane to shift, defaults to both tangential and sagittal.

check_rtl()[source]

property phi: phi : float, optional Microscopic tuning of the surface (in degrees).

set_RTL(R=None, T=None, L=None)[source]

Set the values for the R, T and L properties of the surface.

One of the following combination must be specified:

R and T or,

R and L or,

T and L or,

R and T and L

In the first three cases, the remaining parameter is set via the condition,

\[R + T + L = 1 \]

Parameters

Rscalar: Value of the reflectivity to set.
Tscalar: Value of the transmissivity to set.
Lscalar: Value of the loss to set.

Raises

ValueError

If a combination other than one of the above is specified.

Or if R, T and L are all given but they sum to anything other than one.

property xbeta: Misalignment (x)

property ybeta: Misalignment (y)