class Double_Interaction_BRDF_Model
The class Double_Interaction_BRDF_Model
implements the double interaction model for light
scattering from a spherical particle above a surface. This is a ray tracing approximation and
does not consider the interaction between the particle and its image in the substrate.
Parameters:
| Parameter | Data Type | Description | Default |
|---|---|---|---|
| lambda | double | Wavelength of the light
in vacuum [µm]. (Inherited from BRDF_Model.) |
0.532 |
| type | int |
Indicates whether the light is incident from above the
substrate or from within the substrate and whether the
scattering is evaluated in reflection or transmission.
The choices are: 0 : Light is incident from the above the substrate, and scattering is evaluated in reflection. 1 : Light is incident from the above the substrate, and scattering is evaluated in transmission. 2 : Light is incident from the within the substrate, and scattering is evaluated in reflection. 3 : Light is incident from the within the substrate, and scattering is evaluated in transmission. For 1, 2, and 3, the substrate must be non-absorbing. (Inherited from BRDF_Model). |
0 |
| substrate | dielectric_function | The
optical constants of the substrate, expressed as a
complex number (n,k) or, optionally, as a function of
wavelength. (Inherited from BRDF_Model.) |
(4.05,0.05) |
| density | double | The
surface number density of local scatterers
[µm-2]. (Inherited from Local_BRDF_Model.) |
1 |
| stack | StackModel_Ptr | Description of any stack of films deposited on the substrate. | No_StackModel |
| distance | double | The distance from the surface to the center of the particle [µm]. For a sphere touching a surface, the distance should be the same as the sphere's radius. This parameter should be at least as large as the radius of the particle, if the particle is spherical. | 0.05 |
| scatterer | Free_Space_Scatterer_Ptr | The model
describing the scattering by a particle. The medium surrounding the sphere (scatterer.medium) must be the same as the substrate
(substrate), and the wavelength (scatterer.lambda) must match the model wavelength (lambda).
|
MieScatterer |
| alpha | double | The rotation of the particle about the z-axis [rad]. This parameter only has an effect if the particle is non-axially symmetric. (Note that all models currently inheriting Free_Space_Scatterer are axially symmetric.) | 0 |
| beta | double | The rotation of the particle about the y-axis [rad]. This rotation follows the rotation alpha about the z-axis. This parameter only has an effect if the particle is non-spherical. To further rotate the particle about the z-axis after rotation about the y-axis, the user should evaluate the scattering in a rotated geometry. | 0 |
See also:
SCATMECH Home, Conventions, BRDF_Model, Local_BRDF_Model, Abstract class SphericalScatterer, class RayleighScatterer, class RayleighGansScatterer, class MieScatterer, dielectric_stack
K. B. Nahm and W. L. Wolfe, "Light-scattering models for spheres on a conducting plane: comparison with experiment," Appl. Opt. 26, 2995-2999 (1987).
T. A. Germer, "Angular dependence and polarization of out-of-plane optical scattering from particulate contamination, subsurface defects, and surface microroughness," Appl. Opt. 36, 8798-8805 (1997).
Include file:
#include "sphprt.h"
Source code:
sphprt.cpp
Definition of public elements:
class Double_Interaction_BRDF_Model
: public Local_BRDF_Model
{
};
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Current SCATMECH version: 7.22 (April 2021)