From a70687f5e39b27bf9a579529f51f566fead577e1 Mon Sep 17 00:00:00 2001 From: jan Date: Thu, 21 Dec 2017 20:11:42 -0800 Subject: [PATCH] add bloch example --- examples/bloch.py | 68 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 examples/bloch.py diff --git a/examples/bloch.py b/examples/bloch.py new file mode 100644 index 0000000..8bbd30e --- /dev/null +++ b/examples/bloch.py @@ -0,0 +1,68 @@ +import numpy, scipy, gridlock, fdfd_tools +from fdfd_tools import bloch +from numpy.linalg import norm +import logging + +logging.basicConfig(level=logging.DEBUG) +logger = logging.getLogger(__name__) + + +dx = 40 +x_period = 400 +y_period = z_period = 2000 +g = gridlock.Grid([numpy.arange(-x_period/2, x_period/2, dx), + numpy.arange(-1000, 1000, dx), + numpy.arange(-1000, 1000, dx)], + shifts=numpy.array([[0,0,0]]), + initial=1.445**2, + periodic=True) + +g.draw_cuboid([0,0,0], [200e8, 220, 220], eps=3.47**2) + +#x_period = y_period = z_period = 13000 +#g = gridlock.Grid([numpy.arange(3), ]*3, +# shifts=numpy.array([[0, 0, 0]]), +# initial=2.0**2, +# periodic=True) + +g2 = g.copy() +g2.shifts = numpy.zeros((6,3)) +g2.grids = [numpy.zeros(g.shape) for _ in range(6)] + +epsilon = [g.grids[0],] * 3 +reciprocal_lattice = numpy.diag(1e6/numpy.array([x_period, y_period, z_period])) #cols are vectors + +#print('Finding k at 1550nm') +#k, f = bloch.find_k(frequency=1/1550, +# tolerance=(1/1550 - 1/1551), +# direction=[1, 0, 0], +# G_matrix=reciprocal_lattice, +# epsilon=epsilon, +# band=0) +# +#print("k={}, f={}, 1/f={}, k/f={}".format(k, f, 1/f, norm(reciprocal_lattice @ k) / f )) + +print('Finding f at [0.25, 0, 0]') +for k0x in [.25]: + k0 = numpy.array([k0x, 0, 0]) + + kmag = norm(reciprocal_lattice @ k0) + tolerance = (1e6/1550) * 1e-4/1.5 # df = f * dn_eff / n + logger.info('tolerance {}'.format(tolerance)) + + n, v = bloch.eigsolve(4, k0, G_matrix=reciprocal_lattice, epsilon=epsilon, tolerance=tolerance) + v2e = bloch.hmn_2_exyz(k0, G_matrix=reciprocal_lattice, epsilon=epsilon) + v2h = bloch.hmn_2_hxyz(k0, G_matrix=reciprocal_lattice, epsilon=epsilon) + ki = bloch.generate_kmn(k0, reciprocal_lattice, g.shape) + + z = 0 + e = v2e(v[0]) + for i in range(3): + g2.grids[i] += numpy.real(e[i]) + g2.grids[i+3] += numpy.imag(e[i]) + + f = numpy.sqrt(numpy.real(numpy.abs(n))) # TODO + print('k0x = {:3g}\n eigval = {}\n f = {}\n'.format(k0x, n, f)) + n_eff = norm(reciprocal_lattice @ k0) / f + print('kmag/f = n_eff = {} \n wl = {}\n'.format(n_eff, 1/f )) +