From d1068419f43a0f8c05740eb9e16670137803af9f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Ne=C4=8Dada?= Date: Thu, 14 Nov 2019 17:23:19 +0200 Subject: [PATCH] Finite square lattice scattering script Former-commit-id: d44c0ecb929378e6ede63548bbc47825dacd6088 --- misc/finitesqlat-scatter.py | 147 ++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100755 misc/finitesqlat-scatter.py diff --git a/misc/finitesqlat-scatter.py b/misc/finitesqlat-scatter.py new file mode 100755 index 0000000..a1ab83b --- /dev/null +++ b/misc/finitesqlat-scatter.py @@ -0,0 +1,147 @@ +#!/usr/bin/env python3 + +import argparse +import math + +ap = argparse.ArgumentParser() +ap.add_argument("-p", "--period", type=float, required=True, help='square lattice period') +ap.add_argument("--Nx", type=int, required=True, help='Array size x') +ap.add_argument("--Ny", type=int, required=True, help='Array size y') +ap.add_argument("-f", "--eV", type=float, required=True, help='radiation angular frequency in eV') +ap.add_argument("-m", "--material", help='particle material (Au, Ag for Lorentz-Drue or number for constant refractive index)', default='Au', required=True) +ap.add_argument("-r", "--radius", type=float, required=True, help='particle radius (sphere or cylinder)') +ap.add_argument("-H", "--height", type=float, help='cylindrical particle height; if not provided, particle is assumed to be spherical') +ap.add_argument("-k", '--kx-lim', nargs=2, type=float, required=True, help='k vector', metavar=('KX_MIN', 'KX_MAX')) +# ap.add_argument("--kpi", action='store_true', help="Indicates that the k vector is given in natural units instead of SI, i.e. the arguments given by -k shall be automatically multiplied by pi / period (given by -p argument)") +ap.add_argument("--rank-tol", type=float, required=False) +ap.add_argument("-n", "--refractive-index", type=float, default=1.52, help='background medium refractive index') +ap.add_argument("-L", "--lMax", type=int, required=True, default=3, help='multipole degree cutoff') +ap.add_argument("--lMax-extend", type=int, required=False, default=6, help='multipole degree cutoff for T-matrix calculation (cylindrical particles only') +ap.add_argument("-o", "--output", type=str, required=False, help='output path (if not provided, will be generated automatically)') +ap.add_argument("-N", type=int, default="151", help="Number of angles") +ap.add_argument("-O", "--plot-out", type=str, required=False, help="path to plot output (optional)") +ap.add_argument("-P", "--plot", action='store_true', help="if -p not given, plot to a default path") + + +a=ap.parse_args() + +if a.material in ['Ag', 'Au']: + pass +else: + try: lemat = float(a.material) + except ValueError: + try: lemat = complex(a.material) + except ValueError: + raise ValueError("--material must be either one of 'Ag', 'Au' or a number") + a.material = lemat + +particlestr = ("sph" if a.height is None else "cyl") + ("_r%gnm" % (a.radius*1e9)) +if a.height is not None: particlestr += "_h%gnm" % (a.height * 1e6) +defaultprefix = "%s_p%gnm_%dx%d_m%s_n%g_angles(%g_%g)_Ey_f%geV_L%d_cn%d" % ( + particlestr, a.period*1e9, a.Nx, a.Ny, str(a.material), a.refractive_index, a.kx_lim[0], a.kx_lim[1], a.eV, a.lMax, a.N) +print("Dafault file prefix: %s" % defaultprefix, flush=True) + + +import numpy as np +import qpms +from qpms.cybspec import BaseSpec +from qpms.cytmatrices import CTMatrix, TMatrixGenerator +from qpms.qpms_c import Particle +from qpms.cymaterials import EpsMu, EpsMuGenerator, LorentzDrudeModel, lorentz_drude +from qpms.cycommon import DebugFlags, dbgmsg_enable +from qpms import FinitePointGroup, ScatteringSystem, BesselType, eV, hbar +from qpms.symmetries import point_group_info +eh = eV/hbar + +dbgmsg_enable(DebugFlags.INTEGRATION) + +px=a.period +py=a.period + +#Particle positions +orig_x = (np.arange(a.Nx/2) + (0 if (a.Nx % 2) else .5)) * px +orig_y = (np.arange(a.Ny/2) + (0 if (a.Ny % 2) else .5)) * py + +orig_xy = np.stack(np.meshgrid(orig_x, orig_y), axis = -1) + +medium = EpsMu(a.refractive_index**2) + +if a.material in lorentz_drude: + emg = EpsMuGenerator(lorentz_drude[a.material]) +else: # constant refractive index + emg = EpsMuGenerator(EpsMu(a.material**2)) + +if a.height is None: + tmgen = TMatrixGenerator.sphere(medium, emg, a.radius) +else: + tmgen = TMatrixGenerator.cylinder(medium, emg, a.radius, a.height, lMax_extend=a.lMax_extend) + +omega = a.eV * eh + +bspec = BaseSpec(lMax = a.lMax) +Tmatrix = tmgen(bspec, omega) +particles= [Particle(orig_xy[i], Tmatrix) for i in np.ndindex(orig_xy.shape[:-1])] + +sym = FinitePointGroup(point_group_info['D2h']) +ss = ScatteringSystem(particles, sym) + +wavenumber = medium.k(omega).real # Currently, ScatteringSystem does not "remember" frequency nor wavenumber + +sinalpha_list = np.linspace(a.kx_lim[0],a.kx_lim[1],a.N) + +# Plane wave data +E_cart_list = np.empty((a.N,3), dtype=complex) +E_cart_list[:,:] = np.array((0,1,0))[None,:] +k_cart_list = np.empty((a.N,3), dtype=float) +k_cart_list[:,0] = sinalpha_list +k_cart_list[:,1] = 0 +k_cart_list[:,2] = np.sqrt(1-sinalpha_list**2) +k_cart_list *= wavenumber + +σ_ext_list_ir = np.empty((a.N, ss.nirreps), dtype=float) +σ_scat_list_ir = np.empty((a.N, ss.nirreps), dtype=float) + +for iri in range(ss.nirreps): + LU = ss.scatter_solver(wavenumber,iri) + translation_matrix = ss.translation_matrix_packed(wavenumber, iri, BesselType.REGULAR) + np.eye(ss.saecv_sizes[iri]) + + for j in range(a.N): + # the following two could be calculated only once, but probably not a big deal + ã = ss.planewave_full(k_cart=k_cart_list[j], E_cart=E_cart_list[j]) + Tã = ss.apply_Tmatrices_full(ã) + + Tãi = ss.pack_vector(Tã, iri) + ãi = ss.pack_vector(ã, iri) + fi = LU(Tãi) + σ_ext_list_ir[j, iri] = -np.vdot(ãi, fi).real/wavenumber**2 + σ_scat_list_ir[j, iri] = np.vdot(fi,np.dot(translation_matrix, fi)).real/wavenumber**2 + +σ_abs_list_ir = σ_ext_list_ir - σ_scat_list_ir +σ_abs= np.sum(σ_abs_list_ir, axis=-1) +σ_scat= np.sum(σ_scat_list_ir, axis=-1) +σ_ext= np.sum(σ_ext_list_ir, axis=-1) + + +outfile = defaultprefix + ".npz" if a.output is None else a.output +np.savez(outfile, meta=vars(a), k_cart = k_cart_list, E_cart=E_cart_list, σ_ext=σ_ext,σ_abs=σ_abs,σ_scat=σ_scat, + σ_ext_ir=σ_ext_list_ir,σ_abs_ir=σ_abs_list_ir,σ_scat_ir=σ_scat_list_ir, omega=omega, wavenumber=wavenumber + ) +print("Saved to %s" % outfile) + + +if a.plot or (a.plot_out is not None): + from matplotlib import pyplot as plt + fig = plt.figure() + ax = fig.add_subplot(111) + ax.plot(sinalpha_list, σ_ext*1e12,label='$\sigma_\mathrm{ext}$') + ax.plot(sinalpha_list, σ_scat*1e12, label='$\sigma_\mathrm{scat}$') + ax.plot(sinalpha_list, σ_abs*1e12, label='$\sigma_\mathrm{abs}$') + ax.legend() + ax.set_xlabel('$\sin\\alpha$') + ax.set_ylabel('$\sigma/\mathrm{\mu m^2}$') + + plotfile = defaultprefix + ".pdf" if a.plot_out is None else a.plot_out + fig.savefig(plotfile) + +exit(0) +