Lens

class raytracing.Lens(f, diameter=inf, label='')

Bases: Matrix

A thin lens of focal f, null thickness and infinite or finite diameter

Parameters:

f (float) – The focal length of the lens
diameter (float) – The diameter (default=Inf)
label (string) – The label of the lens

Examples

>>> from raytracing import *
>>> #define a lens with f=5 and diameter 20
>>> L=Lens(f=5,diameter=20,label='Lens')
>>> print(L) #print the transfer matrix of the lens
|  1.000    0.000 |
|                 |
| -0.200    1.000 |
f=5.000

displayHalfHeight()

A reasonable height for display purposes for an element, whether it is infinite or not. If the element is infinite, the half-height is currently set to ‘4’ or to the specified minimum half height. If not, it is the apertureDiameter/2.

Returns:: halfHeight – The half height of the optical element
Return type:: float

property forwardSurfaces

A list of surfaces that represents the element for drawing purposes

For a thin lens, obviously the user does not worry about the details of the lens, because they only provide the focal length. We compute a reasonable radius of curvature and provide

property largestDiameter

Largest diameter for a group of elements

Returns:: LargestDiameter – Largest diameter of the element or group of elements. For a Matrix this will simply be the aperture diameter of this element.
Return type:: float

pointsOfInterest(z)

List of points of interest for this element as a dictionary:

Parameters:: z (float) – Position of the lens
Returns:: pointsOfInterest – List of points of interest for the input element
Return type:: List

Methods

`__init__`(f[, diameter, label])
`displayHalfHeight`()	A reasonable height for display purposes for an element, whether it is infinite or not.
`pointsOfInterest`(z)	List of points of interest for this element as a dictionary:

Inherited Methods

`backFocalLength`()	The focal lengths measured from the back vertex.
`backwardConjugate`()	With an image at the back edge of the element, where is the object ? Distance before the element by which a ray must travel to reach the conjugate plane at the back of the element.
`display`()
`effectiveFocalLengths`()	The effective focal lengths calculated from the power (C) of the matrix.
`flipOrientation`()	We flip the element around (as in, we turn a lens around front-back).
`focalDistances`()	This is the synonym of effectiveFocalLengths()
`focusPositions`(z)	Positions of both focal points on either side of the element.
`forwardConjugate`()	With an object at the front edge of the element, where is the image? Distance after the element by which a ray must travel to reach the conjugate plane of the front of the element.
`fromFocusToFocus`()	A simple method to obtain a MatrixGroup that includes all three matrices to travel from the front focus, through the lens, and then to the back focus.
`fromStruct`(theStruct)
`frontFocalLength`()	The focal lengths measured from the front vertex.
`hasFiniteApertureDiameter`()	If the system has a finite aperture size
`magnification`()	The magnification of the element
`mul_beam`(rightSideBeam)	This function calculates the multiplication of a coherent beam with complex radius of curvature q by an ABCD matrix.
`mul_matrix`(rightSideMatrix)	This function is used to combine two elements into a single matrix.
`mul_ray`(rightSideRay)	This function does the multiplication of a ray by a matrix.
`opticalInvariant`(ray1, ray2[, z])	The optical invariant is a quantity that is conserved for any two rays in the system.
`principalPlanePositions`(z)	Positions of the input and output principal planes.
`profileFromRayTraces`(rayTraces[, z])
`toStruct`()
`trace`(ray)	The ray matrix formalism, through multiplication of a ray by a matrix, will give the correct ray but will never consider apertures.
`traceMany`(inputRays[, useOpenCL])	This function trace each ray from a group of rays from front edge of element to the back edge.
`traceManyNative`(inputRays)	This function trace each ray from a group of rays from front edge of element to the back edge.
`traceManyOpenCL`(inputRays)	This function trace each ray from a group of rays from front edge of element to the back edge.
`traceManyThrough`(inputRays[, progress, ...])	This function trace each ray from a list or a Rays() distribution from front edge of element to the back edge.
`traceManyThroughInParallel`(inputRays[, ...])	This is an advanced technique to gain from parallel computation: it is the same as traceManyThrough(), but splits this call in several other parallel processes using the multiprocessing module, which is os-independent.
`traceThrough`(inputRay)	Contrary to trace(), this only returns the last ray.
`transferMatrices`()	The list of Matrix() that corresponds to the propagation through this element (or group).
`transferMatrix`([upTo])	The Matrix() that corresponds to propagation from the edge of the element (z=0) up to distance "upTo" (z=upTo).

Attributes

`Struct`
`determinant`	The determinant of the ABCD matrix is always frontIndex/backIndex, which is often 1.0.
`forwardSurfaces`	A list of surfaces that represents the element for drawing purposes
`hasPower`	If True, then there is a non-null focal length because C!=0.
`isIdentity`
`isImaging`	If B=0, then the matrix represents that transfer from a conjugate plane to another (i.e. object at the front edge and image at the back edge).
`largestDiameter`	Largest diameter for a group of elements
`surfaces`