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SCATMECH > Classes and Functions >
Grating Models >
RCW_Model
class RCW_Model
The class RCW_Model implements Rigorous Coupled-Wave
theory for a grating, as described by
Moharam, et al., with an extension suggested by
Lalanne and Morris, Granet and Guizal, and Li. It accepts a member variable of type
Grating, which describes the
specific profile, and calculates fields in
reflection or transmission in either the "in-plane"
configuration or the conical configuration. The fields outside of the
grating are accessed through the function GetAmplitude(int i), while
diffraction efficiencies are accessed through the function
GetIntensity(int i).
Parameters:
| Parameter |
Data
Type |
Description |
Default |
| order |
int |
The
Fourier order considered in the calculation. The
calculation will expand the dielectric function in a
layer from -order to order. Convergence of the solution should be checked by
varying this parameter. The calculation time will be proportional to the cube of order. |
25 |
| type |
int |
Indicates
whether theory is evaluated in reflection (0) or
transmission (1). |
0 |
| oldmethod |
int |
Indicates
whether or not the extension suggested by Lalanne and Morris, Granet and Guizal, and Li is
used. If oldmethod is 1, then the theory is implemented
as described by Moharam, et al., which typically
converges very slowly for transverse-magnetic (TM)
polarization. If oldmethod is 0, then the extension
is used, which usually
results in much faster convergence for TM polarization. There will be no effect
on the results for transverse-electric (TE) polarization. |
0 |
| lambda |
double |
The
wavelength of the light in vacuum
[µm]. |
0.532 |
| thetai |
double |
The
incident angle, measured from the surface normal [degrees]. |
0 |
| rotation |
double |
The
azimuthal rotation of the sample [degrees].
When rotation is non-zero, the
geometry is considered to be in the conical mount, and
the calculation time is longer.
|
0 |
| grating |
Grating_Ptr |
A
description of the grating profile and optical
properties. |
Single_Line_Grating |
See also:
SCATMECH Home,
MuellerMatrix,
JonesMatrix, Grating
M.G. Moharam, E.B. Grann, D.A. Pommet, and T.K. Gaylord,
"Formulation for stable and efficient implementation of the
rigorous coupled-wave analysis of binary gratings," J. Opt.
Soc. Am. A 12, 1068-1076 (1995).
P. Lalanne and G.M. Morris, "Highly improved convergence of
the coupled-wave method for TM polarization" J. Opt. Soc.
Am. A 13, 779-784 (1996).
G. Granet and B. Buizal, "Efficient implementation of the coupled-wave method
for metallic lamellar gratings in TM polarization," J. Opt. Soc. Am. A 13, 1019-1023 (1996).
L. Li, "Use of Fourier series in the analysis of discontinuous periodic structures," J. Opt. Soc. Am. A 13, 1870-1876 (1996).
Include file:
#include "rcw.h"
Source code:
rcw.cpp
Definition of public and protected elements:
class RCW_Model : public Model {
public:
JonesMatrix GetAmplitude(int i);
MuellerMatrix GetIntensity(int i);
int GetMinimumPropagatingOrder();
int GetMaximumPropagatingOrder();
Vector GetDirection(int i);
CVector GetPropagationVector(int i);
CVector GetEField(const JonesVector& input, const Vector& pos);
CVector GetHField(const JonesVector& input, const Vector& pos);
CVector GetDField(const JonesVector& input, const Vector& pos);
CVector GetBField(const JonesVector& input, const Vector& pos);
};
GetAmplitude(i)
returns the Jones matrix associated with the i-th order
diffraction. The Jones matrix relates the amplitude of the diffracted plane wave
to the amplitude of the incident plane wave.
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GetIntensity(i) returns the Mueller matrix diffraction efficiency (reflectance, if type=0, or transmittance, if type=1) associated with the i-th
order diffraction.
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These functions return the minimum and maximum orders for
which the reflectance or transmittance is propagating.
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GetDirection(i) returns a unit vector in the
direction of propagation of the i-th diffraction order.
It returns a zero vector for those orders which are not
propagating.
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GetPropagationVector(i) returns the complex propagation vector
for the i-th diffraction order.
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These functions return the amplitude of the electric field (GetEField), the magnetic field (GetHField),
the electric displacement (GetDField), and the magnetic induction (GetBField), evaluated at location pos for a
given incident Jones vector input. Locations are defined with respect to the top of the grating (incident beam side), with positive z coordinates
being in the incident half-space. At this time, the fields can only be evaluated outside of the grating, and only in the region defined by parameter type.
That is, if type is 0, the fields can be evaluated above the grating, and if type is 1, the fields can be evaluated below the grating.
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Current SCATMECH version: 6.00 (February 2008)
This page first online: Version 6.00 (February 2008)
This page last modified: Version 6.00 (February 2008)
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