def example5():
"""Another code example, and loading / saving factory."""
code = """V = 10
ncl = 1.444
k0 = 2 * pi / 1550e-9
n = sqrt((V / (k0 * r[0]))**2 - ncl**2)
return n
"""
factory = FiberFactory()
factory.addLayer(radius={'start': 1e-6, 'end': 10e-6, 'num': 10},
index=code)
factory.addLayer(index=1.444)
print(len(factory))
print('crdate:', datetime.datetime.fromtimestamp(
int(factory.crdate)).strftime('%Y-%m-%d %H:%M:%S'))
print('tstamp:', datetime.datetime.fromtimestamp(
int(factory.tstamp)).strftime('%Y-%m-%d %H:%M:%S'))
with open('myfiber.json', 'w') as f:
factory.dump(f)
with open('myfiber.json', 'r') as f:
factory.load(f)
print(len(factory))
print('crdate:', datetime.datetime.fromtimestamp(
int(factory.crdate)).strftime('%Y-%m-%d %H:%M:%S'))
print('tstamp:', datetime.datetime.fromtimestamp(
int(factory.tstamp)).strftime('%Y-%m-%d %H:%M:%S'))
factory = FiberFactory('myfiber.json')
print(len(factory))
print('crdate:', datetime.datetime.fromtimestamp(
int(factory.crdate)).strftime('%Y-%m-%d %H:%M:%S'))
print('tstamp:', datetime.datetime.fromtimestamp(
int(factory.tstamp)).strftime('%Y-%m-%d %H:%M:%S'))
def example2():
"""Plotting neff as function of the wavelength"""
wavelengths = numpy.linspace(1530e-9, 1580e-9, 11)
factory = FiberFactory()
factory.addLayer(radius=4e-6, index=1.474)
factory.addLayer()
sim = Simulator(factory, wavelengths, delta=1e-5)
neffiter = sim.neff()
neffs = next(neffiter)
for mode in next(sim.modes())[0]:
neff = []
for neffwl in neffs: # for each wavelength
try:
neff.append(neffwl[mode])
except KeyError: # mode not supported
neff.append(float("nan"))
neffma = numpy.ma.masked_invalid(neff) # mask "nan"
pyplot.plot(wavelengths*1e9, neffma, label=str(mode))
pyplot.title("neff as function of wavelength")
pyplot.xlabel("wavelength (nm)")
pyplot.ylabel("effective index")
pyplot.legend()
pyplot.show()
def testBures_4_2_8(self):
n2 = 1.457420
n1 = 1.462420
rho = 8.335e-6
wl = Wavelength(0.6328e-6)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
modes = fiber.findLPmodes(wl)
sols = {
Mode('LP', 0, 1): 2.1845,
Mode('LP', 0, 2): 4.9966,
Mode('LP', 0, 3): 7.7642,
Mode('LP', 1, 1): 3.4770,
Mode('LP', 1, 2): 6.3310,
Mode('LP', 1, 3): 9.0463,
Mode('LP', 2, 1): 4.6544,
Mode('LP', 2, 2): 7.5667,
Mode('LP', 3, 1): 5.7740,
Mode('LP', 3, 2): 8.7290,
Mode('LP', 4, 1): 6.8560,
Mode('LP', 4, 2): 9.8153,
Mode('LP', 5, 1): 7.9096,
Mode('LP', 6, 1): 8.9390,
Mode('LP', 7, 1): 9.9451
}
self.assertEqual(len(modes), len(sols))
for m in modes:
neff = fiber.neff(m, wl)
u = wl.k0 * rho * sqrt(n1**2 - neff**2)
self.assertAlmostEqual(u, sols[m], 3)
def testBures_4_2_8(self):
n2 = 1.457420
n1 = 1.462420
rho = 8.335e-6
wl = Wavelength(0.6328e-6)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
modes = fiber.findLPmodes(wl)
sols = {Mode('LP', 0, 1): 2.1845,
Mode('LP', 0, 2): 4.9966,
Mode('LP', 0, 3): 7.7642,
Mode('LP', 1, 1): 3.4770,
Mode('LP', 1, 2): 6.3310,
Mode('LP', 1, 3): 9.0463,
Mode('LP', 2, 1): 4.6544,
Mode('LP', 2, 2): 7.5667,
Mode('LP', 3, 1): 5.7740,
Mode('LP', 3, 2): 8.7290,
Mode('LP', 4, 1): 6.8560,
Mode('LP', 4, 2): 9.8153,
Mode('LP', 5, 1): 7.9096,
Mode('LP', 6, 1): 8.9390,
Mode('LP', 7, 1): 9.9451}
self.assertEqual(len(modes), len(sols))
for m in modes:
neff = fiber.neff(m, wl)
u = wl.k0 * rho * sqrt(n1**2 - neff**2)
self.assertAlmostEqual(u, sols[m], 3)
def testCutoffV(self):
"""Values from Bures, Table 3.6."""
delta = 0.3
V = 5
wl = Wavelength(1.55e-6)
n2 = 1.444
n1 = sqrt(n2**2 / (1 - 2 * delta))
rho = V / (sqrt(n1**2 - n2**2) * wl.k0)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
sols = [(Mode('TE', 0, 1), 2.4048), (Mode('TM', 0, 1), 2.4048),
(Mode('HE', 1, 1), 0), (Mode('EH', 1, 1), 3.8317),
(Mode('TE', 0, 2), 5.5201), (Mode('TM', 0, 2), 5.5201),
(Mode('HE', 1, 2), 3.8317), (Mode('EH', 1, 2), 7.0156),
(Mode('HE', 2, 1), 2.8526), (Mode('EH', 2, 1), 5.1356),
(Mode('HE', 3, 1), 4.3423), (Mode('EH', 2, 2), 8.4172)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def example3():
"""Plotting modal map"""
r2 = 10e-6
rho = numpy.linspace(0, 0.95)
r1 = r2 * rho
Vlim = (2, 6) # interval where to plot V
factory = FiberFactory()
factory.addLayer(radius=r1, index=1.444)
factory.addLayer(radius=r2, index=1.474)
factory.addLayer(index=1.444)
sim = PSimulator(factory, [1550e-9], vectorial=False, scalar=True,
numax=6, mmax=2)
modes = set()
for ml in sim.modes():
modes |= ml[0]
CO = list(sim.cutoff())
for mode in sorted(modes):
vco = numpy.fromiter((co[0][mode] if mode in co[0] else float("nan")
for co in CO),
dtype=float, count=rho.size)
vco = numpy.ma.masked_invalid(vco)
if vco.min() < Vlim[1] and vco.max() > Vlim[0]:
pyplot.plot(vco, rho, label=str(mode))
pyplot.title("Modal map")
pyplot.xlabel("V number")
pyplot.ylabel("r1 / r2")
pyplot.xlim(Vlim)
pyplot.ylim((0, 1))
pyplot.show()
def testBures3_6(self):
delta = 0.3
V = 5
wl = Wavelength(1.55e-6)
n2 = 1.444
n1 = sqrt(n2**2 / (1 - 2 * delta))
rho = V / (sqrt(n1**2 - n2**2) * wl.k0)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
modes = fiber.findVmodes(wl)
sols = {Mode('HE', 1, 1): 2.119,
Mode('TE', 0, 1): 3.153,
Mode('TM', 0, 1): 3.446,
Mode('HE', 2, 1): 3.377,
Mode('EH', 1, 1): 4.235,
Mode('HE', 3, 1): 4.507,
Mode('HE', 1, 2): 4.638}
self.assertEqual(len(modes), len(sols))
for m in modes:
neff = fiber.neff(m, wl)
u = wl.k0 * rho * sqrt(n1**2 - neff**2)
self.assertAlmostEqual(u, sols[m], 3)
def plot_zoom(fiber, vlim=(4.6, 5.4), blim=(0, 0.04)):
fig = pyplot.figure(figsize=(6, 5))
ax = fig.add_subplot(111, xlim=vlim, ylim=blim)
sns.despine(fig)
name, r, n = fiber
ax.set_title(name)
f = FiberFactory()
for (r_, n_) in zip_longest(r, n):
f.addLayer(radius=r_, index=n_)
fiber = f[0]
V = numpy.linspace(*vlim)
wl = [fiber.toWl(v) for v in V[::-1]]
sim = Simulator(f, wl, delta=1e-7)
co = next(sim.cutoff())
b = next(sim.b())
for mode, cutoff in co[0].items():
if cutoff == 0:
continue # skip HE(1,1) / LP(0,1)
color = MODE_COLORS[str(mode)]
ax.axvline(cutoff, ls=':', color=color)
b_ = numpy.empty(len(wl))
for j, b__ in enumerate(b):
b_[j] = b__.get(mode, float("nan"))
ax.plot(V[::-1],
b_,
color=color,
label=str(mode) if mode.nu in (1, 3) else None)
ax.set_ylabel("Normalized propagation constant ($b$)")
ax.set_xlabel("Normalized frequency ($V_0$)")
ax.legend(loc='best')
fig.tight_layout()
def testBures3_6(self):
delta = 0.3
V = 5
wl = Wavelength(1.55e-6)
n2 = 1.444
n1 = sqrt(n2**2 / (1 - 2 * delta))
rho = V / (sqrt(n1**2 - n2**2) * wl.k0)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
modes = fiber.findVmodes(wl)
sols = {
Mode('HE', 1, 1): 2.119,
Mode('TE', 0, 1): 3.153,
Mode('TM', 0, 1): 3.446,
Mode('HE', 2, 1): 3.377,
Mode('EH', 1, 1): 4.235,
Mode('HE', 3, 1): 4.507,
Mode('HE', 1, 2): 4.638
}
self.assertEqual(len(modes), len(sols))
for m in modes:
neff = fiber.neff(m, wl)
u = wl.k0 * rho * sqrt(n1**2 - neff**2)
self.assertAlmostEqual(u, sols[m], 3)
def testCutoffV(self):
"""Values from Bures, Table 3.6."""
delta = 0.3
V = 5
wl = Wavelength(1.55e-6)
n2 = 1.444
n1 = sqrt(n2**2 / (1 - 2 * delta))
rho = V / (sqrt(n1**2 - n2**2) * wl.k0)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
sols = [(Mode('TE', 0, 1), 2.4048),
(Mode('TM', 0, 1), 2.4048),
(Mode('HE', 1, 1), 0),
(Mode('EH', 1, 1), 3.8317),
(Mode('TE', 0, 2), 5.5201),
(Mode('TM', 0, 2), 5.5201),
(Mode('HE', 1, 2), 3.8317),
(Mode('EH', 1, 2), 7.0156),
(Mode('HE', 2, 1), 2.8526),
(Mode('EH', 2, 1), 5.1356),
(Mode('HE', 3, 1), 4.3423),
(Mode('EH', 2, 2), 8.4172)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def plot_zoom(fiber, vlim=(4.6, 5.4), blim=(0, 0.04)):
fig = pyplot.figure(figsize=(6, 5))
ax = fig.add_subplot(111, xlim=vlim, ylim=blim)
sns.despine(fig)
name, r, n = fiber
ax.set_title(name)
f = FiberFactory()
for (r_, n_) in zip_longest(r, n):
f.addLayer(radius=r_, index=n_)
fiber = f[0]
V = numpy.linspace(*vlim)
wl = [fiber.toWl(v) for v in V[::-1]]
sim = Simulator(f, wl, delta=1e-7)
co = next(sim.cutoff())
b = next(sim.b())
for mode, cutoff in co[0].items():
if cutoff == 0:
continue # skip HE(1,1) / LP(0,1)
color = MODE_COLORS[str(mode)]
ax.axvline(cutoff, ls=':', color=color)
b_ = numpy.empty(len(wl))
for j, b__ in enumerate(b):
b_[j] = b__.get(mode, float("nan"))
ax.plot(V[::-1], b_, color=color,
label=str(mode) if mode.nu in (1, 3) else None)
ax.set_ylabel("Normalized propagation constant ($b$)")
ax.set_xlabel("Normalized frequency ($V_0$)")
ax.legend(loc='best')
fig.tight_layout()
def testCutoffV2(self):
"""Values from cutoff acticle, Table III."""
n1 = 1.474
n2 = 1.444
rho = 10e-6
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
sols = [(Mode('TE', 0, 1), 2.4048),
(Mode('HE', 2, 1), 2.4221),
(Mode('TM', 0, 1), 2.4048),
(Mode('EH', 1, 1), 3.8317),
(Mode('HE', 3, 1), 3.8533),
(Mode('HE', 1, 2), 3.8317),
(Mode('EH', 2, 1), 5.1356),
(Mode('HE', 4, 1), 5.1597),
(Mode('TE', 0, 2), 5.5201),
(Mode('HE', 2, 2), 5.5277),
(Mode('TM', 0, 2), 5.5201)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def testEqualIndexes(self):
f = FiberFactory()
f.addLayer(radius=1e-6, index=1.474)
f.addLayer(radius=4e-6, index=1.474)
f.addLayer()
fiber = f[0]
self.assertEqual(len(fiber), 2)
def testDefaultLayerAttributes(self):
f = FiberFactory()
f.addLayer()
self.assertEqual(f.layers[0].mparams[0], 1.444)
self.assertEqual(f.layers[0].material, "Fixed")
self.assertEqual(f.layers[0].type, "StepIndex")
self.assertEqual(f.layers[0].radius, 0)
def example3():
"""2. Creating families of fibers: range of parameters"""
factory = FiberFactory()
factory.addLayer(name="core",
radius={'start': 2e-6, 'end': 5e-6, 'num': 10},
index=[1.454, 1.464, 1.474])
factory.addLayer(name="cladding")
print('Number of generated fibers:', len(factory))
def testEqualIndexes(self):
f = FiberFactory()
f.addLayer(radius=1e-6, index=1.474)
f.addLayer(radius=4e-6, index=1.474)
f.addLayer()
fiber = f[0]
self.assertEqual(len(fiber), 2)
def testDefaultLayerAttributes(self):
f = FiberFactory()
f.addLayer()
self.assertEqual(f.layers[0].mparams[0], 1.444)
self.assertEqual(f.layers[0].material, "Fixed")
self.assertEqual(f.layers[0].type, "StepIndex")
self.assertEqual(f.layers[0].radius, 0)
def plot_b_vs_V(vectorial=True, scalar=False):
nf = len(FIBERS)
fig, axes = pyplot.subplots(nf,
1,
sharex=False,
sharey=False,
subplot_kw={
'xlim': VLIM,
'ylim': (0, 0.3)
},
figsize=(6, 9))
sns.despine(fig)
lines = {}
for i, (name, r, n) in enumerate(FIBERS):
axes[i].set_title(name)
f = FiberFactory()
for (r_, n_) in zip_longest(r, n):
f.addLayer(radius=r_, index=n_)
fiber = f[0]
V = numpy.linspace(*VLIM)
wl = [fiber.toWl(v) for v in V[::-1]]
sim = Simulator(f, wl, vectorial=vectorial, scalar=scalar, delta=1e-5)
co = next(sim.cutoff())
b = next(sim.b())
assert len(b) == len(wl)
for mode, cutoff in co[0].items():
if cutoff == 0:
continue # skip HE(1,1) / LP(0,1)
color = MODE_COLORS[str(mode)]
axes[i].axvline(cutoff, ls=':', color=color)
b_ = numpy.empty(len(wl))
for j, b__ in enumerate(b):
b_[j] = b__.get(mode, float("nan"))
lines[mode], = axes[i].plot(V[::-1], b_, color=color)
if i == 1 and vectorial is True: # fiber b
r = Rectangle((4.6, 0), 0.8, 0.04, alpha=.3, facecolor='grey')
axes[i].add_patch(r)
handles = [lines[k] for k in sorted(lines)]
labels = [str(k) for k in sorted(lines)]
leg = fig.legend(handles,
labels,
loc='upper left',
bbox_to_anchor=(0.18, 1),
frameon=True)
frame = leg.get_frame()
frame.set_linewidth(0)
fig.text(0.04,
0.5,
"Normalized propagation constant ($b$)",
rotation='vertical',
ha='center',
va='center')
axes[-1].set_xlabel("Normalized frequency ($V_0$)")
fig.tight_layout(rect=(0.04, 0, 1, 1))
def testFindLPmodes(self):
f = FiberFactory()
f.addLayer(radius=4.5e-6, index=1.448918)
f.addLayer(index=1.444418)
fiber = f[0]
wl = Wavelength(800e-9)
modes = fiber.findLPmodes(wl)
self.assertEqual(len(modes), 4)
def testFindLPmodes(self):
f = FiberFactory()
f.addLayer(radius=4.5e-6, index=1.448918)
f.addLayer(index=1.444418)
fiber = f[0]
wl = Wavelength(800e-9)
modes = fiber.findLPmodes(wl)
self.assertEqual(len(modes), 4)
def testSetAttributes(self):
f = FiberFactory()
f.name = "smf28"
f.author = "Charles Brunet"
f.description = "Single mode fiber"
f.addLayer()
f.layers[0].name = "core"
self.assertEqual(f.name, "smf28")
self.assertEqual(f.author, "Charles Brunet")
self.assertEqual(f.description, "Single mode fiber")
self.assertEqual(f.layers[0].name, "core")
def testSetAttributes(self):
f = FiberFactory()
f.name = "smf28"
f.author = "Charles Brunet"
f.description = "Single mode fiber"
f.addLayer()
f.layers[0].name = "core"
self.assertEqual(f.name, "smf28")
self.assertEqual(f.author, "Charles Brunet")
self.assertEqual(f.description, "Single mode fiber")
self.assertEqual(f.layers[0].name, "core")
def testFundamental(self):
f = FiberFactory()
f.addLayer(radius=4.5e-6, index=1.448918)
f.addLayer(index=1.444418)
fiber = f[0]
wl = Wavelength(1550e-9)
neff = fiber.neff(Mode('HE', 1, 1), wl)
self.assertAlmostEqual(neff, 1.4464045, places=5)
lp01 = fiber.neff(Mode('LP', 0, 1), wl)
self.assertAlmostEqual(lp01, neff, places=5)
def testFundamental(self):
f = FiberFactory()
f.addLayer(radius=4.5e-6, index=1.448918)
f.addLayer(index=1.444418)
fiber = f[0]
wl = Wavelength(1550e-9)
neff = fiber.neff(Mode('HE', 1, 1), wl)
self.assertAlmostEqual(neff, 1.4464045, places=5)
lp01 = fiber.neff(Mode('LP', 0, 1), wl)
self.assertAlmostEqual(lp01, neff, places=5)
def testCutoffLP(self):
f = FiberFactory()
f.addLayer(radius=1e-5 / 3, index=5)
f.addLayer(index=4)
fiber = f[0]
sols = [(Mode('LP', 0, 1), 0), (Mode('LP', 0, 2), 3.8317),
(Mode('LP', 0, 3), 7.0156), (Mode('LP', 1, 1), 2.4048),
(Mode('LP', 1, 2), 5.5201), (Mode('LP', 2, 1), 3.8317)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def example2():
"""2. Creating families of fibers: list of parameters"""
# Varying core radius
factory = FiberFactory()
factory.addLayer(name="core", radius=[1e-6, 2e-6, 3e-6, 4e-6, 5e-6],
index=1.474)
factory.addLayer()
for i, fiber in enumerate(factory):
print(factory.layers[0].radius[i],
fiber.neff(Mode("HE", 1, 1), 1550e-9))
# Varying core index
n = numpy.linspace(1.454, 1.494)
factory = FiberFactory()
factory.addLayer(name="core", radius=4e-6, index=n)
factory.addLayer(name="cladding")
fibers = list(factory)
print(fibers)
neff = numpy.zeros(n.shape)
for i, fiber in enumerate(factory):
neff[i] = fiber.neff(Mode("HE", 1, 1), 1550e-9)
pyplot.plot(n, neff)
pyplot.title("neff as function of core index (HE 1,1 mode)")
pyplot.xlabel("core index")
pyplot.ylabel("effective index")
pyplot.show()
def main():
wl = Wavelength(1550e-9)
ff1 = FiberFactory()
ff1.addLayer(name="core",
radius=8e-6,
material="Fixed",
geometry="StepIndex",
index=1.454)
ff1.addLayer(name="cladding", index=1.444)
fiber1 = ff1[0]
neff1 = fiber1.neff(Mode("HE", 1, 1), wl)
print(neff1)
ff2 = FiberFactory()
ff2.addLayer(name="core",
radius=8e-6,
material="Fixed",
geometry="SuperGaussian",
tparams=[0, 2e-6, 1],
index=1.454)
ff2.addLayer(name="cladding", index=1.444)
fiber2 = ff2[0]
neff2 = fiber2.neff(Mode("HE", 1, 1), wl, lowbound=neff1)
print(neff2)
def testSetFactory(self):
sim = self.Simulator()
sim.set_factory(os.path.join(__dir__, '..', 'fiber', 'rcfs.fiber'))
self.assertEqual(len(sim.fibers), 5)
f = FiberFactory()
f.addLayer(radius=[4e-6, 5e-6, 6e-6], index=1.449)
f.addLayer(index=1.444)
sim.set_factory(f)
self.assertEqual(len(sim.fibers), 3)
with self.assertRaises(ValueError):
sim.wavelengths
self.assertFalse(sim.initialized)
self.assertTrue(sim._fsims is None)
def fromVDelta(V, Delta, wl):
"""To match Bures examples
params(3.9, 0.26, wl) # Bures 3.25
"""
nco = numpy.sqrt(1.444**2 / (1 - Delta * 2))
rho = V / wl.k0 / numpy.sqrt(nco**2 - 1.444**2)
f = FiberFactory()
f.addLayer(name="core", radius=rho, index=nco)
f.addLayer(name="cladding", index=1.444)
fiber = f[0]
print(fiber)
return fiber
def fromVDelta(V, Delta, wl):
"""To match Bures examples
params(3.9, 0.26, wl) # Bures 3.25
"""
nco = numpy.sqrt(1.444**2 / (1 - Delta*2))
rho = V / wl.k0 / numpy.sqrt(nco**2 - 1.444**2)
f = FiberFactory()
f.addLayer(name="core", radius=rho, index=nco)
f.addLayer(name="cladding", index=1.444)
fiber = f[0]
print(fiber)
return fiber
def testCutoffLP(self):
f = FiberFactory()
f.addLayer(radius=1e-5 / 3, index=5)
f.addLayer(index=4)
fiber = f[0]
sols = [(Mode('LP', 0, 1), 0),
(Mode('LP', 0, 2), 3.8317),
(Mode('LP', 0, 3), 7.0156),
(Mode('LP', 1, 1), 2.4048),
(Mode('LP', 1, 2), 5.5201),
(Mode('LP', 2, 1), 3.8317)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def example4():
"""2. Creating families of fibers: parameter as code"""
factory = FiberFactory()
factory.addLayer(radius="return 4e-6", index="return 1.474")
factory.addLayer()
fiber = factory[0]
print('core radius:', fiber.outerRadius(0))
print('core index:', fiber.maxIndex(0, 1550e-9))
factory = FiberFactory()
factory.addLayer(radius={'start': 1e-6, 'end': 10e-6, 'num': 10})
factory.addLayer(radius="return r[0] + 2e-6", index=1.474)
factory.addLayer()
print('layer 0 radius', '/', 'layer 1 radius')
for fiber in factory:
print(fiber.outerRadius(0), '/', fiber.outerRadius(1))
def ACF():
f = FiberFactory()
f.addLayer(name="air", radius=9.1e-6, material="Air")
f.addLayer(name="ring", radius=11.3e-6, material="SiO2GeO2", x=0.192)
f.addLayer(name="trench", radius=16.2e-6, material="SiO2F", x=0.013)
f.addLayer(name="cladding", material="Silica")
fiber = f[0]
print(fiber)
return fiber
def ACF():
f = FiberFactory()
f.addLayer(name="air", radius=9.1e-6, material="Air")
f.addLayer(name="ring", radius=11.3e-6, material="SiO2GeO2", x=0.192)
f.addLayer(name="trench", radius=16.2e-6, material="SiO2F", x=0.013)
f.addLayer(name="cladding", material="Silica")
fiber = f[0]
print(fiber)
return fiber
def testFindVmodes(self):
f = FiberFactory()
f.addLayer(radius=4.5e-6, index=1.448918)
f.addLayer(index=1.444418)
fiber = f[0]
wl = Wavelength(800e-9)
modes = fiber.findVmodes(wl)
sols = [(Mode('HE', 1, 1), 1.4479082), (Mode('TE', 0, 1), 1.44643),
(Mode('HE', 2, 1), 1.446427), (Mode('TM', 0, 1), 1.4464268),
(Mode('EH', 1, 1), 1.444673), (Mode('HE', 3, 1), 1.444669),
(Mode('HE', 1, 2), 1.4444531)]
self.assertEqual(len(modes), len(sols))
for mode, neff in sols:
self.assertTrue(mode in modes)
self.assertAlmostEqual(fiber.neff(mode, wl), neff)
def main():
delta = 0.3
V = 5
wl = Wavelength(1.55e-6)
n2 = 1.444
n1 = sqrt(n2**2 / (1 - 2 * delta))
rho = V / (sqrt(n1**2 - n2**2) * wl.k0)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
modes = fiber.findVmodes(wl)
for m in modes:
neff = fiber.neff(m, wl, delta=1e-5)
def main():
delta = 0.3
V = 5
wl = Wavelength(1.55e-6)
n2 = 1.444
n1 = sqrt(n2**2 / (1 - 2 * delta))
rho = V / (sqrt(n1**2 - n2**2) * wl.k0)
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
modes = fiber.findVmodes(wl)
for m in modes:
neff = fiber.neff(m, wl, delta=1e-5)
def plot_b_vs_V(vectorial=True, scalar=False):
nf = len(FIBERS)
fig, axes = pyplot.subplots(nf, 1, sharex=False, sharey=False,
subplot_kw={'xlim': VLIM, 'ylim': (0, 0.3)},
figsize=(6, 9))
sns.despine(fig)
lines = {}
for i, (name, r, n) in enumerate(FIBERS):
axes[i].set_title(name)
f = FiberFactory()
for (r_, n_) in zip_longest(r, n):
f.addLayer(radius=r_, index=n_)
fiber = f[0]
V = numpy.linspace(*VLIM)
wl = [fiber.toWl(v) for v in V[::-1]]
sim = Simulator(f, wl, vectorial=vectorial, scalar=scalar, delta=1e-5)
co = next(sim.cutoff())
b = next(sim.b())
assert len(b) == len(wl)
for mode, cutoff in co[0].items():
if cutoff == 0:
continue # skip HE(1,1) / LP(0,1)
color = MODE_COLORS[str(mode)]
axes[i].axvline(cutoff, ls=':', color=color)
b_ = numpy.empty(len(wl))
for j, b__ in enumerate(b):
b_[j] = b__.get(mode, float("nan"))
lines[mode], = axes[i].plot(V[::-1], b_, color=color)
if i == 1 and vectorial is True: # fiber b
r = Rectangle((4.6, 0), 0.8, 0.04, alpha=.3, facecolor='grey')
axes[i].add_patch(r)
handles = [lines[k] for k in sorted(lines)]
labels = [str(k) for k in sorted(lines)]
leg = fig.legend(handles, labels, loc='upper left',
bbox_to_anchor=(0.18, 1), frameon=True)
frame = leg.get_frame()
frame.set_linewidth(0)
fig.text(0.04, 0.5, "Normalized propagation constant ($b$)",
rotation='vertical', ha='center', va='center')
axes[-1].set_xlabel("Normalized frequency ($V_0$)")
fig.tight_layout(rect=(0.04, 0, 1, 1))
def testFindVmodes(self):
f = FiberFactory()
f.addLayer(radius=4.5e-6, index=1.448918)
f.addLayer(index=1.444418)
fiber = f[0]
wl = Wavelength(800e-9)
modes = fiber.findVmodes(wl)
sols = [(Mode('HE', 1, 1), 1.4479082),
(Mode('TE', 0, 1), 1.44643),
(Mode('HE', 2, 1), 1.446427),
(Mode('TM', 0, 1), 1.4464268),
(Mode('EH', 1, 1), 1.444673),
(Mode('HE', 3, 1), 1.444669),
(Mode('HE', 1, 2), 1.4444531)]
self.assertEqual(len(modes), len(sols))
for mode, neff in sols:
self.assertTrue(mode in modes)
self.assertAlmostEqual(fiber.neff(mode, wl), neff)
def testCutoffV2(self):
"""Values from cutoff acticle, Table III."""
n1 = 1.474
n2 = 1.444
rho = 10e-6
f = FiberFactory()
f.addLayer(radius=rho, index=n1)
f.addLayer(index=n2)
fiber = f[0]
sols = [(Mode('TE', 0, 1), 2.4048), (Mode('HE', 2, 1), 2.4221),
(Mode('TM', 0, 1), 2.4048), (Mode('EH', 1, 1), 3.8317),
(Mode('HE', 3, 1), 3.8533), (Mode('HE', 1, 2), 3.8317),
(Mode('EH', 2, 1), 5.1356), (Mode('HE', 4, 1), 5.1597),
(Mode('TE', 0, 2), 5.5201), (Mode('HE', 2, 2), 5.5277),
(Mode('TM', 0, 2), 5.5201)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def testToWl(self):
f = FiberFactory(os.path.join(__dir__, 'smf28.fiber'))
fiber = f[0]
self.assertAlmostEqual(fiber.toWl(fiber.V0(1600e-9)), 1600e-9)
f.layers[0].material = "Silica"
f.layers[1].material = "Air"
fiber = f[0]
self.assertAlmostEqual(fiber.toWl(fiber.V0(1600e-9)), 1600e-9)
self.assertEqual(fiber.toWl(float("inf")), 0)
self.assertTrue(isinf(fiber.toWl(0)))
with warnings.catch_warnings():
warnings.filterwarnings("ignore", category=OutOfRangeWarning)
f = FiberFactory()
f.addLayer(radius=10e-6, material="SiO2GeO2", x=0.25)
f.addLayer(material="Silica")
fiber = f[0]
wl = fiber.toWl(2.4)
self.assertGreater(wl, 10e-6)
def testToWl(self):
f = FiberFactory(os.path.join(__dir__, 'smf28.fiber'))
fiber = f[0]
self.assertAlmostEqual(fiber.toWl(fiber.V0(1600e-9)), 1600e-9)
f.layers[0].material = "Silica"
f.layers[1].material = "Air"
fiber = f[0]
self.assertAlmostEqual(fiber.toWl(fiber.V0(1600e-9)), 1600e-9)
self.assertEqual(fiber.toWl(float("inf")), 0)
self.assertTrue(isinf(fiber.toWl(0)))
with warnings.catch_warnings():
warnings.filterwarnings("ignore", category=OutOfRangeWarning)
f = FiberFactory()
f.addLayer(radius=10e-6, material="SiO2GeO2", x=0.25)
f.addLayer(material="Silica")
fiber = f[0]
wl = fiber.toWl(2.4)
self.assertGreater(wl, 10e-6)
def example1():
"""1. Defining fiber layers"""
factory = FiberFactory()
factory.name = "Name of your fiber"
factory.author = "Your Name"
factory.description = "Description of your fiber"
print('crdate:', datetime.datetime.fromtimestamp(
int(factory.crdate)).strftime('%Y-%m-%d %H:%M:%S'))
print('tstamp:', datetime.datetime.fromtimestamp(
int(factory.tstamp)).strftime('%Y-%m-%d %H:%M:%S'))
# Default parameters
factory.addLayer()
# Comp material: molar fraction
factory.addLayer(pos=0, name="core", geometry="StepIndex", radius=4e-6,
material="SiO2GeO2", x=0.1)
# Comp material: index and wavelength
factory.addLayer(pos=1, name="trench", radius=6e-6, material="SiO2F",
index=1.441, wl=1550e-9)
# Getting information from layers
print('Name of layer 0:', factory.layers[0].name)
print('Radius of layer 1:', factory.layers[1].radius)
factory.layers[2].name = "cladding"
print('Name of layer 2:', factory.layers[2].name)
def testCutoffV3(self):
"""Same index for n1 and n2; therefore this is SSIF."""
n1 = 1.6
n2 = 1.6
n3 = 1.4
rho1 = 5e-6
rho2 = 6e-6
f = FiberFactory()
f.addLayer(radius=rho1, index=n1)
f.addLayer(radius=rho2, index=n2)
f.addLayer(index=n3)
fiber = f[0]
sols = [(Mode('TE', 0, 1), 2.4048),
(Mode('HE', 2, 1), 2.522748641920963),
(Mode('TM', 0, 1), 2.4048), (Mode('EH', 1, 1), 3.8317),
(Mode('HE', 3, 1), 3.9762622998101453),
(Mode('HE', 1, 2), 3.8317)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def testCutoffV3(self):
"""Same index for n1 and n2; therefore this is SSIF."""
n1 = 1.6
n2 = 1.6
n3 = 1.4
rho1 = 5e-6
rho2 = 6e-6
f = FiberFactory()
f.addLayer(radius=rho1, index=n1)
f.addLayer(radius=rho2, index=n2)
f.addLayer(index=n3)
fiber = f[0]
sols = [(Mode('TE', 0, 1), 2.4048),
(Mode('HE', 2, 1), 2.522748641920963),
(Mode('TM', 0, 1), 2.4048),
(Mode('EH', 1, 1), 3.8317),
(Mode('HE', 3, 1), 3.9762622998101453),
(Mode('HE', 1, 2), 3.8317)]
for mode, V0 in sols:
self.assertAlmostEqual(fiber.cutoff(mode), V0, 4, msg=str(mode))
def example1():
"""Counting modes and finding cutoffs."""
factory = FiberFactory()
factory.addLayer(radius=10e-6, index=1.474)
factory.addLayer()
# Print list of modes
sim = Simulator(factory, [1550e-9])
modes = next(sim.modes())[0] # modes of first wavelength of next fiber
print(", ".join(str(mode) for mode in sorted(modes)))
print()
# Print cutoff (as V number)
cutoffs = next(sim.cutoff())[0] # first wavelength of next fiber
for mode, co in cutoffs.items():
print(str(mode), co)
print()
# Print cutoff (as wavelength)
cutoffswl = next(sim.cutoffWl())[0] # first wavelength of next fiber
for mode, co in cutoffswl.items():
print(str(mode), str(co))
print()
def testImpossibleRadius(self):
"""TODO: not implemented yet"""
f = FiberFactory()
f.addLayer(radius=10e-6, index=1.174)
f.addLayer(radius=4e-6, index=1.444)
f.addLayer()
self.assertEqual(len(f), 0)
def testImpossibleRadius(self):
"""TODO: not implemented yet"""
f = FiberFactory()
f.addLayer(radius=10e-6, index=1.174)
f.addLayer(radius=4e-6, index=1.444)
f.addLayer()
self.assertEqual(len(f), 0)
def _testFiberCutoffs(self, r, n):
f = FiberFactory()
for r_, n_ in zip_longest(r, n):
f.addLayer(radius=r_, index=n_)
fiber = f[0]
for nu in range(1, 5):
pco = -1
for m in range(1, 5):
for fam in (ModeFamily.HE, ModeFamily.EH):
mode = Mode(fam, nu, m)
co = fiber.cutoff(mode)
self.assertGreater(co, pco, "Not greater "+str(mode))
if mode != HE11:
d = 0.
b = float("nan")
while isnan(b):
d += 0.25
wl = fiber.toWl(co + d)
b = fiber.b(mode, wl, delta=1e-5)
self.assertLess(b, 0.1, "Wrong b "+str(mode))
pco = co
def _testFiberCutoffs(self, r, n):
f = FiberFactory()
for r_, n_ in zip_longest(r, n):
f.addLayer(radius=r_, index=n_)
fiber = f[0]
for nu in range(1, 5):
pco = -1
for m in range(1, 5):
for fam in (ModeFamily.HE, ModeFamily.EH):
mode = Mode(fam, nu, m)
co = fiber.cutoff(mode)
self.assertGreater(co, pco, "Not greater " + str(mode))
if mode != HE11:
d = 0.
b = float("nan")
while isnan(b):
d += 0.25
wl = fiber.toWl(co + d)
b = fiber.b(mode, wl, delta=1e-5)
self.assertLess(b, 0.1, "Wrong b " + str(mode))
pco = co
def RCF2():
x = 0.19
r1 = 125 * 1.4 / 180 * 1e-6
r2 = 125 * 4 / 180 * 1e-6
f = FiberFactory()
f.addLayer(name="center", radius=r1, material="Silica")
f.addLayer(name="ring", radius=r2, material="SiO2GeO2", x=x)
f.addLayer(name="cladding", material="Silica")
fiber = f[0]
print(fiber)
return fiber
def RCF2():
x = 0.19
r1 = 125 * 1.4 / 180 * 1e-6
r2 = 125 * 4 / 180 * 1e-6
f = FiberFactory()
f.addLayer(name="center", radius=r1, material="Silica")
f.addLayer(name="ring", radius=r2, material="SiO2GeO2", x=x)
f.addLayer(name="cladding", material="Silica")
fiber = f[0]
print(fiber)
return fiber
def compute_fiber(filename, nrho, R2, C2, wl, numax=None, mmax=None):
# Initialize simulators
sim = []
for i, r2 in enumerate(R2):
r1 = numpy.linspace(0, r2, nrho, endpoint=False)
factory = FiberFactory()
factory.addLayer(radius=r1, material='Silica')
factory.addLayer(radius=r2, material='SiO2GeO2', x=C2)
factory.addLayer(material='Silica')
sim.append(Simulator(factory, wl))
nr2 = R2.size
nc2 = C2.size
ckfile, _ = os.path.splitext(filename)
ckfile += '.ckp.npz'
if os.path.isfile(ckfile):
# Restore checkpoint
data = numpy.load(ckfile)
modes = [Mode(*a) for a in data['modes']]
results = {'modes': modes}
for fct in ('cutoff', 'neff', 'beta1', 'beta2', 'beta3'):
results[fct] = data[fct]
else:
# Find modes
sim[-1].numax = numax
sim[-1].mmax = mmax
modes = find_mode_list(sim[-1])
# Initialize arrays
shape = (nrho, nr2, C2.size, len(modes))
results = {'modes': modes}
for fct in ('cutoff', 'neff', 'beta1', 'beta2', 'beta3'):
results[fct] = numpy.empty(shape)
results[fct].fill(numpy.nan)
Rho = numpy.linspace(0, 1, nrho, endpoint=False)
for i, r2 in enumerate(R2[::-1], 1):
print("Solving when r2={:.3f}µm".format(r2 * 1e6))
if numpy.all(numpy.isnan(results['cutoff'][:, nr2 - i, :, :])):
numax, mmax = compute_fiber_r2(results, modes, sim[-i], nr2 - i,
Rho, r2, nc2, numax, mmax)
numpy.savez_compressed(ckfile, **results) # Save checkpoint
os.rename(ckfile, filename)
return results
def build_factory(nr1, r2, cn2):
"""Create a FiberFactory for RCF from given arguments.
Args:
nr1(int): Number of points for r1
r2(float): Radius r2
cn2(float): Concentration for ring-core
Returns;
FiberFactory
"""
r1 = numpy.linspace(0, r2, nr1, endpoint=False)
factory = FiberFactory()
factory.addLayer(radius=r1, material='Silica')
factory.addLayer(radius=r2, material='SiO2GeO2', x=cn2)
factory.addLayer(material='Silica')
return factory