def get_sample():
"""
Returns a sample with a grating on a substrate,
modelled by infinitely long boxes forming a 1D lattice.
"""
# defining materials
m_ambience = ba.HomogeneousMaterial("Air", 0.0, 0.0)
m_substrate = ba.HomogeneousMaterial("Substrate", 6e-6, 2e-8)
m_particle = ba.HomogeneousMaterial("Particle", 6e-4, 2e-8)
# collection of particles
lattice_length = 100.0 * nm
lattice_rotation_angle = 0.0 * deg
interference = ba.InterferenceFunction1DLattice(lattice_length,
lattice_rotation_angle)
pdf = ba.FTDecayFunction1DCauchy(1e+6)
interference.setDecayFunction(pdf)
box_ff = ba.FormFactorBox(1000 * nm, 20 * nm, 10.0 * nm)
box = ba.Particle(m_particle, box_ff)
transform = ba.RotationZ(90.0 * deg)
particle_layout = ba.ParticleLayout()
particle_layout.addParticle(box, 1.0, ba.kvector_t(0.0, 0.0, 0.0),
transform)
particle_layout.setInterferenceFunction(interference)
# assembling the sample
air_layer = ba.Layer(m_ambience)
air_layer.addLayout(particle_layout)
substrate_layer = ba.Layer(m_substrate)
multi_layer = ba.MultiLayer()
multi_layer.addLayer(air_layer)
multi_layer.addLayer(substrate_layer)
return multi_layer
def get_sample(lattice_rotation_angle=0.0 * deg):
"""
Returns a sample with a grating on a substrate.
lattice_rotation_angle = 0 - beam parallel to grating lines
lattice_rotation_angle = 90*deg - beam perpendicular to grating lines
"""
# defining materials
m_ambience = ba.HomogeneousMaterial("Air", 0.0, 0.0)
m_si = ba.HomogeneousMaterial("Si", 5.78164736e-6, 1.02294578e-7)
box_length, box_width, box_height = 50 * micrometer, 70 * nm, 50 * nm
lattice_length = 150 * nm
# collection of particles
interference = ba.InterferenceFunction1DLattice(
lattice_length, 90.0 * deg - lattice_rotation_angle)
pdf = ba.ba.FTDecayFunction1DGauss(450.0)
interference.setDecayFunction(pdf)
box_ff = ba.FormFactorLongBoxLorentz(box_length, box_width, box_height)
box = ba.Particle(m_si, box_ff)
particle_layout = ba.ParticleLayout()
particle_layout.addParticle(box, 1.0, ba.kvector_t(0.0, 0.0, 0.0),
ba.RotationZ(lattice_rotation_angle))
particle_layout.setInterferenceFunction(interference)
# assembling the sample
air_layer = ba.Layer(m_ambience)
air_layer.addLayout(particle_layout)
substrate_layer = ba.Layer(m_si)
roughness = ba.LayerRoughness()
roughness.setSigma(5.0 * nm)
roughness.setHurstParameter(0.5)
roughness.setLatteralCorrLength(10.0 * nm)
multi_layer = ba.MultiLayer()
multi_layer.addLayer(air_layer)
multi_layer.addLayerWithTopRoughness(substrate_layer, roughness)
return multi_layer
def get_sample(lattice_rotation_angle=45 * deg):
"""
Returns a sample with a grating on a substrate,
modelled by very long boxes forming a 1D lattice with Cauchy correlations.
"""
# defining materials
m_vacuum = ba.HomogeneousMaterial("Vacuum", 0.0, 0.0)
m_substrate = ba.HomogeneousMaterial("Substrate", 6e-6, 2e-8)
m_particle = ba.HomogeneousMaterial("Particle", 6e-4, 2e-8)
box_length, box_width, box_height = 10 * nm, 10000 * nm, 10 * nm
lattice_length = 30 * nm
# collection of particles
interference = ba.InterferenceFunction1DLattice(lattice_length,
lattice_rotation_angle)
pdf = ba.FTDecayFunction1DCauchy(1000.0)
interference.setDecayFunction(pdf)
box_ff = ba.FormFactorBox(box_length, box_width, box_height)
box = ba.Particle(m_particle, box_ff)
particle_layout = ba.ParticleLayout()
particle_layout.addParticle(box, 1.0, ba.kvector_t(0.0, 0.0, 0.0),
ba.RotationZ(lattice_rotation_angle))
particle_layout.setInterferenceFunction(interference)
# assembling the sample
vacuum_layer = ba.Layer(m_vacuum)
vacuum_layer.addLayout(particle_layout)
substrate_layer = ba.Layer(m_substrate)
multi_layer = ba.MultiLayer()
multi_layer.addLayer(vacuum_layer)
multi_layer.addLayer(substrate_layer)
return multi_layer
