misc/finiterectlat-scatter.py

   1 #!/usr/bin/env python3
   2
   3 import math
   4 from qpms.argproc import ArgParser
   5
   6
   7 ap = ArgParser(['rectlattice2d_finite', 'single_particle', 'single_lMax', 'single_omega'])
   8 ap.add_argument("-k", '--kx-lim', nargs=2, type=float, required=True, help='k vector', metavar=('KX_MIN', 'KX_MAX'))
   9 # 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)")
  10 ap.add_argument("-o", "--output", type=str, required=False, help='output path (if not provided, will be generated automatically)')
  11 ap.add_argument("-N", type=int, default="151", help="Number of angles")
  12 ap.add_argument("-O", "--plot-out", type=str, required=False, help="path to plot output (optional)")
  13 ap.add_argument("-P", "--plot", action='store_true', help="if -p not given, plot to a default path")
  14 ap.add_argument("-g", "--save-gradually", action='store_true', help="saves the partial result after computing each irrep")
  15
  16
  17 a=ap.parse_args()
  18
  19 import logging
  20 logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)
  21
  22 Nx, Ny = a.size
  23 px, py = a.period
  24
  25 particlestr = ("sph" if a.height is None else "cyl") + ("_r%gnm" % (a.radius*1e9))
  26 if a.height is not None: particlestr += "_h%gnm" % (a.height * 1e9)
  27 defaultprefix = "%s_p%gnmx%gnm_%dx%d_m%s_n%g_angles(%g_%g)_Ey_f%geV_L%d_cn%d" % (
  28     particlestr, px*1e9, py*1e9, Nx, Ny, str(a.material), a.refractive_index, a.kx_lim[0], a.kx_lim[1], a.eV, a.lMax, a.N)
  29 logging.info("Default file prefix: %s" % defaultprefix)
  30
  31
  32 import numpy as np
  33 import qpms
  34 from qpms.cybspec import BaseSpec
  35 from qpms.cytmatrices import CTMatrix, TMatrixGenerator
  36 from qpms.qpms_c import Particle
  37 from qpms.cymaterials import EpsMu, EpsMuGenerator, LorentzDrudeModel, lorentz_drude
  38 from qpms.cycommon import DebugFlags, dbgmsg_enable
  39 from qpms import FinitePointGroup, ScatteringSystem, BesselType, eV, hbar
  40 from qpms.symmetries import point_group_info
  41 eh = eV/hbar
  42
  43 dbgmsg_enable(DebugFlags.INTEGRATION)
  44
  45 #Particle positions
  46 orig_x = (np.arange(Nx/2) + (0 if (Nx % 2) else .5)) * px
  47 orig_y = (np.arange(Ny/2) + (0 if (Ny % 2) else .5)) * py
  48
  49 orig_xy = np.stack(np.meshgrid(orig_x, orig_y), axis = -1)
  50
  51
  52 omega = ap.omega
  53
  54 bspec = BaseSpec(lMax = a.lMax)
  55 Tmatrix = ap.tmgen(bspec, ap.omega)
  56 particles= [Particle(orig_xy[i], Tmatrix) for i in np.ndindex(orig_xy.shape[:-1])]
  57
  58 sym = FinitePointGroup(point_group_info['D2h'])
  59 ss = ScatteringSystem(particles, sym)
  60
  61 wavenumber = ap.background_epsmu.k(omega).real # Currently, ScatteringSystem does not "remember" frequency nor wavenumber
  62
  63 sinalpha_list = np.linspace(a.kx_lim[0],a.kx_lim[1],a.N)
  64
  65 # Plane wave data
  66 E_cart_list = np.empty((a.N,3), dtype=complex)
  67 E_cart_list[:,:] = np.array((0,1,0))[None,:]
  68 k_cart_list = np.empty((a.N,3), dtype=float)
  69 k_cart_list[:,0] = sinalpha_list
  70 k_cart_list[:,1] = 0
  71 k_cart_list[:,2] = np.sqrt(1-sinalpha_list**2)
  72 k_cart_list *= wavenumber
  73
  74 σ_ext_list_ir = np.empty((a.N, ss.nirreps), dtype=float)
  75 σ_scat_list_ir = np.empty((a.N, ss.nirreps), dtype=float)
  76
  77 outfile_tmp = defaultprefix + ".tmp" if a.output is None else a.output + ".tmp"
  78
  79 for iri in range(ss.nirreps):
  80     logging.info("processing irrep %d/%d" % (iri, ss.nirreps))
  81     LU = None # to trigger garbage collection before the next call
  82     translation_matrix = None
  83     LU = ss.scatter_solver(wavenumber,iri)
  84     logging.info("LU solver created")
  85     translation_matrix = ss.translation_matrix_packed(wavenumber, iri, BesselType.REGULAR) + np.eye(ss.saecv_sizes[iri])
  86     logging.info("auxillary translation matrix created")
  87
  88     for j in range(a.N):
  89         # the following two could be calculated only once, but probably not a big deal
  90         ã = ss.planewave_full(k_cart=k_cart_list[j], E_cart=E_cart_list[j])
  91         Tã = ss.apply_Tmatrices_full(ã)
  92
  93         Tãi = ss.pack_vector(Tã, iri)
  94         ãi = ss.pack_vector(ã, iri)
  95         fi = LU(Tãi)
  96         σ_ext_list_ir[j, iri] = -np.vdot(ãi, fi).real/wavenumber**2
  97         σ_scat_list_ir[j, iri] = np.vdot(fi,np.dot(translation_matrix, fi)).real/wavenumber**2
  98     if a.save_gradually:
  99         iriout = outfile_tmp + ".%d" % iri
 100         np.savez(iriout, iri=iri, meta=vars(a), sinalpha=sinalpha_list, k_cart = k_cart_list, E_cart=E_cart_list,
 101                  omega=omega, wavenumber=wavenumber, σ_ext_list_ir=σ_ext_list_ir[:,iri], σ_scat_list_ir=σ_scat_list_ir[:,iri])
 102         logging.info("partial results saved to %s"%iriout)
 103
 104 σ_abs_list_ir = σ_ext_list_ir - σ_scat_list_ir
 105 σ_abs= np.sum(σ_abs_list_ir, axis=-1)
 106 σ_scat= np.sum(σ_scat_list_ir, axis=-1)
 107 σ_ext= np.sum(σ_ext_list_ir, axis=-1)
 108
 109
 110 outfile = defaultprefix + ".npz" if a.output is None else a.output
 111 np.savez(outfile, meta=vars(a), sinalpha=sinalpha_list, k_cart = k_cart_list, E_cart=E_cart_list, σ_ext=σ_ext,σ_abs=σ_abs,σ_scat=σ_scat,
 112  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
 113        )
 114 logging.info("Saved to %s" % outfile)
 115
 116
 117 if a.plot or (a.plot_out is not None):
 118     import matplotlib
 119     matplotlib.use('pdf')
 120     from matplotlib import pyplot as plt
 121
 122     fig = plt.figure()
 123     ax = fig.add_subplot(111)
 124     ax.plot(sinalpha_list, σ_ext*1e12,label='$\sigma_\mathrm{ext}$')
 125     ax.plot(sinalpha_list, σ_scat*1e12, label='$\sigma_\mathrm{scat}$')
 126     ax.plot(sinalpha_list, σ_abs*1e12, label='$\sigma_\mathrm{abs}$')
 127     ax.legend()
 128     ax.set_xlabel('$\sin\\alpha$')
 129     ax.set_ylabel('$\sigma/\mathrm{\mu m^2}$')
 130
 131     plotfile = defaultprefix + ".pdf" if a.plot_out is None else a.plot_out
 132     fig.savefig(plotfile)
 133
 134 exit(0)
 135