finesse.components.surface.Surface.actuate_roc

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.