Custom Mathematical Operations

Allows the user to augment the functionality of OPTISCAN through use of custom mathematical electric field calculations.

Overview:

In order to use a Custom Mathematical Operation object, you need to create an m-file which uses the following function declaration formation:

function [mop, curlink, simdata, errmsg] = function_name(action, mop curlink, simdata);

if the function call is successful, the the function should set the output variable as follows:

errmsg = ”;

if the function call is not successful, and therefore the simulation should be stopped, then errmsg should be set equal to a description of the error that occurred:

errmsg = ‘The Input Field Cannot be Zero’;

Sometimes it is important for the mathematical operation to know what kind of input link is connected to it. This can be done by querying curlink for its linktype :

if istransmitted(curlink)
 %the input linktype is transmitted
 elseif isreflected(curlink)
 %the input linktype is reflected
 else
 %an electric field is not explicitly being transmitted to
 %the MOP object.
 end

For the following configuration:

source-to-MOP

the istransmitted(curlink) function would return “true” since the input link is propagating transmitted electric fields to the MOP object. The electric fields can be retrieved through the simdata variable:

transmitted fields

Ext = simdata.Ext
Eyt = simdata.Eyt
Ezt = simdata.Ezt

reflected fields

Exr = simdata.Exr
Eyt = simdata.Eyr
Ezt = simdata.Ezr

The ordinate and abcissa vectors can be similarly queried using:

sysxvec = simdata.sysxvec; %x-positions of each column
sysyvec = simdata.sysyvec; %y-positions of each row

After the function is finished modifying the fields and/or the ordinate and abcissa vectors, it needs to update the simdata variable using:

simdate.Ext = Ext;
simdata.Eyt = Eyt;
etc….

The MOP function may wish to save some information between invocations. The simdata variable allows the function to retrieve the custom “user data” that is associated with a specific MOP object by using:

userdata = simdata.userdata

if isempty(userdata)
 %need to initialize the userdata
 userdata.sinvector = sin( linspace(0,2*pi,100);
 userdata.cosvector = cos( linspace(0,2*pi,100);
 end

After the custom “user data” is initialized and/or updated, it can be stored by using:

simdata.userdata = userdata;

The following is a list of other simdata properties that may be useful:

  • simdata.NHighNA – number of samples to use for High Numerical Aperature optics calculations.
  • simdata.NLowNa – number of samples to use for Low Numerical Aperature optics calculations.
  • simdata.LAMBDA – the current value for LAMBDA
  • simdata.SourceType – 1 for coherent, 2 for incoherent.
  • simdata.SourceTypePoints – number of source points for an incoherent source.
  • simdata.PointCount – current source point number for an incoherent source.
  • simdata.VisitCount – number of times that the current object has been calculated.

The project directory may be determined using:

project_path = fullfile(mop,”,”);

Example – this simple MOP function calculates the Total Aerial Irradiance of the input fields and stores it in Ext:

function [mop, curlink, simdata, errmsg] = mymop(action, mop, curlink, simdata)

errmsg = '';

%retreive the desired electric fields:

if istransmitted(curlink)
ex = simdata.Ext;
ey = simdata.Eyt;
ez = simdata.Ezt;
elseif istransmitted(curlink)
ex = simdata.Exr;
ey = simdata.Eyr;
ez = simdata.Ezr;
else
errmsg = 'Need an Input Link!'; return;
end;

%store the calculated "Total Aerial Irradiance" in ex:

ex = 3*10^8*0.5*8.85e-12*(abs(ex).^2+abs(ey).^2+abs(ez).^2);

%

set the other fields to 0

ey = 0;
ez = 0;

%update the source fieds
simdata.Ext = ex;
simdata.Eyt = ey;
simdata.Ezt = ez;

simdata.Exr = 0;
simdata.Eyr = 0;
simdata.Ezr = 0;

An example system where this script might be used is calculating the Total Aerial Irradiance of a source, even though the Source Editor can do this for you without any programming at all:

mopsystem

Configurable Variables – A MOP function can be used in conjunction with a Delta Object. For more information about this advanced feature, see the information on Configurable Variables.

mopsystem.2 – Delta Object used with a MOP object.