### Interference - Rectangular Grating

This example demonstrates how to perform a simulation of a grating using very long boxes and a 1D lattice. Interference of a 1D lattice may provide useful background information.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68  #!/usr/bin/env python3 """ Simulation of grating using very long boxes and 1D lattice. Monte-carlo integration is used to get rid of large-particle form factor oscillations. """ import bornagain as ba from bornagain import ba_plot as bp, deg, micrometer, nm def get_sample(lattice_rotation_angle=0*deg): """ 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 """ # Materials vacuum = ba.RefractiveMaterial("Vacuum", 0, 0) material_si = ba.RefractiveMaterial("Si", 5.7816e-6, 1.0229e-7) box_length, box_width, box_height = 50*micrometer, 70*nm, 50*nm lattice_length = 150*nm # Particle layout interference = ba.Interference1DLattice( lattice_length, 90*deg - lattice_rotation_angle) pdf = ba.Profile1DGauss(450) interference.setDecayFunction(pdf) box_ff = ba.LongBoxLorentz(box_length, box_width, box_height) box = ba.Particle(material_si, box_ff) box.rotate(ba.RotationZ(lattice_rotation_angle)) particle_layout = ba.ParticleLayout() particle_layout.addParticle(box) particle_layout.setInterference(interference) # Sample vacuum_layer = ba.Layer(vacuum) vacuum_layer.addLayout(particle_layout) substrate_layer = ba.Layer(material_si) sigma, hurst, corrLength = 5*nm, 0.5, 10*nm autocorr = ba.K_CorrelationModel(sigma, hurst, corrLength) interlayer = ba.TanhInterlayer() roughness = ba.LayerRoughness(autocorr, interlayer) sample = ba.MultiLayer() sample.addLayer(vacuum_layer) sample.addLayerWithTopRoughness(substrate_layer, roughness) return sample def get_simulation(sample): beam = ba.Beam(1e8, 0.134*nm, 0.4*deg) n = 200 detector = ba.SphericalDetector(n, -0.5*deg, 0.5*deg, n, 0, 0.5*deg) simulation = ba.ScatteringSimulation(beam, sample, detector) simulation.options().setMonteCarloIntegration(True, 100) return simulation if __name__ == '__main__': sample = get_sample() simulation = get_simulation(sample) result = simulation.simulate() bp.plot_simulation_result(result) bp.show_or_export() 
auto/Examples/scatter2d/RectangularGrating.py

To get rid of oscillation arising from large-particle form factors, Monte-carlo integration is used.

auto/Examples/scatter2d/GratingMC.py