def double_rr(wave,
width,
thickness,
radius,
gap,
sw_angle=90,
term='k',
part='mag'):
"""Return coupling coefficients for a Racetrack Resonator
Args:
wave (float/np.ndarray): wavelength in nm (1450 - 1650nm)
width (float/np.ndarray): width of waveguide in nm (400 - 600nm)
thickness (float/np.ndarray): thickness of waveguide in nm (180 - 240nm)
radius (float/np.ndarray): radius of rings in nm
gap (float/np.ndarray): gap between rings in nm(above 100nm)
sw_angle (float/np.ndarray): angle of waveguide walls in degrees (between 80 and 90)
term (str): either 't' or 'k'
part (str): 'mag', 'phase', or 'both'. Choose both if you want both phase and magnitude
Returns:
(complex np.ndarray): The coupling coefficient"""
#clean everything
wave, width, thickness, sw_angle, radius, gap = clean_inputs(
(wave, width, thickness, sw_angle, radius, gap))
#get coefficients
ae, ao, ge, go, neff = get_coeffs(wave, width, thickness, sw_angle)
#calculate everything
B = lambda x: (np.pi * 2 * x * np.exp(-2 * x) *
(special.iv(1, 2 * x) + special.modstruve(-1, 2 * x))) / 2
xe = ge * (radius + width / 2)
xo = go * (radius + width / 2)
z = 2 * (radius + width)
#get closed form solution
return get_closed_ans(ae, ao, ge, go, neff, wave, B, xe, xo, z, gap, term,
part)
def predict(self, ports, wavelength):
wavelength, width, thickness, sw_angle, radius, gap = self.clean_args(
wavelength)
ae, ao, ge, go, neff = get_coeffs(wavelength, width, thickness,
sw_angle)
#make sure ports are valid
if not all(1 <= x <= 4 for x in ports):
raise ValueError('Invalid Ports')
#determine if cross or through port
if abs(ports[1] - ports[0]) == 2:
trig = np.cos
offset = 0
else:
trig = np.sin
offset = np.pi / 2
#determine z distance
if 1 in ports and 3 in ports:
z_dist = np.pi * radius
elif 1 in ports and 4 in ports:
z_dist = np.pi * radius
elif 2 in ports and 4 in ports:
z_dist = np.pi * radius
elif 2 in ports and 3 in ports:
z_dist = np.pi * radius
#if it's coming to itself, or to adjacent port
else:
return np.zeros(len(wavelength))
#calculate everything
B = lambda x: 0.5 * np.pi * 2 * x * np.exp(-2 * x) * (special.iv(
1, 2 * x) + special.modstruve(-1, 2 * x))
xe = ge * (radius + width / 2)
xo = go * (radius + width / 2)
return get_closed_ans(ae, ao, ge, go, neff, wavelength, gap, B, xe, xo,
offset, trig, z_dist)
def _init_values_modstruve(self):
temp_values = np.arange(0, 10, 0.001)
self.value_map = special.modstruve(2, temp_values)
c_max = np.amax(self.value_map)
np.multiply(self.value_map, 1.0 / c_max, out=self.value_map)
self.value_map = np.concatenate((self.value_map, self.value_map[::-1]))
L_v = 2.7 * L_1
# Upward
sigma_w = 0.5 * sigma_1
L_w = 0.66 * L_1
U = (4 * L_u / V_ref) * sigma_u**2 / (
(1 + 6 * f * L_u / V_ref)**(5. / 3.))
V = (4 * L_v / V_ref) * sigma_v**2 / (
(1 + 6 * f * L_v / V_ref)**(5. / 3.))
W = (4 * L_w / V_ref) * sigma_w**2 / (
(1 + 6 * f * L_w / V_ref)**(5. / 3.))
kappa = 12 * np.sqrt((f / V_ref)**2 + (0.12 / L_u)**2)
Rot = (2*U / (R * kappa)**3) * \
(modstruve(1,2*R*kappa) - iv(1,2*R*kappa) - 2/np.pi + \
R*kappa * (-2 * modstruve(-2,2*R*kappa) + 2 * iv(2,2*R*kappa) + 1) )
# set NaNs to 0
Rot[np.isnan(Rot)] = 0
# Formulas from Section 6.3 of IEC 61400-1-2019
# S_1_f = 0.05 * sigma_1**2. * (L_1 / V_hub) ** (-2./3.) * f **(-5./3)
# S_2_f = S_3_f = 4. / 3. * S_1_f
# sigma_k = np.sqrt(np.trapz(S_1_f, f))
# print(sigma_k)
# print(sigma_u)
return U, V, W, Rot
def FourierIntegral(k):
return sqrt(pi / 2) * (1 / k - special.kv(0, k) * special.modstruve(-1, k)
- special.kv(0, k) * special.modstruve(0, k))
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import matplotlib.pyplot as plt
import numpy as np
from scipy import special
fig = plt.figure()
ax = fig.gca(projection='3d')
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = special.modstruve(0,R)
surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=cm.coolwarm, linewidth=0, antialiased=False)
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()
#Modstruve
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import matplotlib.pyplot as plt
from scipy import special
import numpy as np
fig = plt.figure()
ax = fig.gca(projection='3d')
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = special.modstruve(6, R)
surf = ax.plot_surface(X,
Y,
Z,
rstride=1,
cstride=1,
cmap=cm.coolwarm,
linewidth=0,
antialiased=False)
ax.set_zlim(None, None)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()
def racetrack(wave,
width,
thickness,
radius,
gap,
length,
sw_angle=90,
term='k',
part='mag'):
"""Return coupling coefficients for a Racetrack Resonator
Args:
wave (float/np.ndarray): wavelength in nm (1450 - 1650nm)
width (float/np.ndarray): width of waveguide in nm (400 - 600nm)
thickness (float/np.ndarray): thickness of waveguide in nm (180 - 240nm)
radius (float/np.ndarray): radius of ring in nm
gap (float/np.ndarray): gap between bus and ring in nm(above 100nm)
length (float/np.ndarray): Length of straight portion of resonator in nm
sw_angle (float/np.ndarray): angle of waveguide walls in degrees (between 80 and 90)
term (str): either 't' or 'k'
part (str): 'mag', 'phase', or 'both'. Choose both if you want both phase and magnitude
Returns:
(complex np.ndarray): The coupling coefficient"""
#clean everything
wave, width, thickness, sw_angle, radius, gap, length = clean_inputs(
(wave, width, thickness, sw_angle, radius, gap, length))
#get coefficients
ae, ao, ge, go, neff_str = get_coeffs(wave, width, thickness, sw_angle)
neff_bent = R_bent.predict(
np.column_stack((wave / 1000, width / 1000, thickness / 1000,
radius / 1000, sw_angle)))
#calculate everything
B = lambda x: length * x / (radius + width / 2) + np.pi * x * np.exp(
-x) * (special.iv(1, x) + special.modstruve(-1, x))
xe = ge * (radius + width / 2)
xo = go * (radius + width / 2)
z = 2 * (radius + width) + length
#get closed form solution
#determine which parameter to get
if term == 'k':
trig = np.sin
offset = np.pi / 2
z_str = (radius + width / 2 + length)
z_bent = np.pi * radius / 2
elif term == 't':
trig = np.cos
offset = 0
z_str = 2 * (radius + width / 2) + length
z_bent = 0
else:
raise ValueError("Bad term parameter")
#calculate magnitude
if part == 'mag' or part == 'both':
temp = ae * np.exp(-ge * gap) * B(xe) / ge + ao * np.exp(
-go * gap) * B(xo) / go
mag = trig(temp * np.pi / wave)
#calculate phase
if part == 'ph' or part == 'both':
temp = ae * np.exp(-ge * gap) * B(xe) / ge - ao * np.exp(
-go * gap) * B(xo) / go + 2 * (z_str * neff_str +
z_bent * neff_bent)
phase = (temp * np.pi / wave + offset)
if part == 'mag':
phase = 0
if part == 'ph':
mag = 1
return mag * np.exp(-1j * phase)
