def main():
# -- DEFINE SIMULATION PARAMETERS
# ... COMPUTATIONAL DOMAIN
t_max = 4000. # (fs)
t_num = 2**14 # (-)
z_max = 6.0e6 # (micron)
z_num = 75000 # (-)
z_skip= 100 # (-)
n2 = 3.0e-8 # (micron^2/W)
beta_fun = define_beta_fun_ESM()
pc = PropConst(beta_fun)
# -- INITIALIZATION STAGE
grid = Grid( t_max = t_max, t_num = t_num, z_max = z_max, z_num = z_num)
#print(grid.dz)
#exit()
model = FMAS_S_Raman(w=grid.w, beta_w=pc.beta(grid.w), n2=n2)
solver = IFM_RK4IP( model.Lw, model.Nw, user_action = model.claw)
# -- SET UP INITIAL CONDITION
t = grid.t
# ... FUNDAMENTAL NSE SOLITON
w0_S, t0_S = 1.5, 20. # (rad/fs), (fs)
A0 = np.sqrt(abs(pc.beta2(w0_S))*model.c0/w0_S/n2)/t0_S
A0_S = A0/np.cosh(t/t0_S)*np.exp(1j*w0_S*t)
# ... 1ST DISPERSIVE WAVE; UNITS (rad/fs), (fs), (fs), (-)
w0_DW1, t0_DW1, t_off1, s1 = 2.06, 60., -600., 0.35
A0_DW1 = s1*A0/np.cosh((t-t_off1)/t0_DW1)*np.exp(1j*w0_DW1*t)
# ... 2ND DISPERSIVE WAVE; UNITS (rad/fs), (fs), (fs), (-)
w0_DW2, t0_DW2, t_off2, s2 = 2.05, 60., -1200., 0.35
A0_DW2 = s2*A0/np.cosh((t-t_off2)/t0_DW2)*np.exp(1j*w0_DW2*t)
# ... 3RD DISPERSIVE WAVE; UNITS (rad/fs), (fs), (fs), (-)
w0_DW3, t0_DW3, t_off3, s3 = 2.04, 60., -1800., 0.35
A0_DW3 = s3*A0/np.cosh((t-t_off3)/t0_DW3)*np.exp(1j*w0_DW3*t)
# ... ANALYTIC SIGNAL OF FULL ININITIAL CONDITION
Eps_0w = AS(np.real(A0_S + A0_DW1 + A0_DW2 + A0_DW3)).w_rep
solver.set_initial_condition( grid.w, Eps_0w)
solver.propagate( z_range = z_max, n_steps = z_num, n_skip = z_skip)
# -- SHOW RESULTS
v0 = pc.vg(w0_S)
utz = change_reference_frame(solver.w, solver.z, solver.uwz, v0)
res = {
't': grid.t,
'w': grid.w,
'z': solver.z,
'v0': pc.vg(w0_S),
'utz': utz,
'Cp': solver.ua_vals
}
save_h5('out_file_HR.h5', **res)
def main():
# -- INITIALIZATION STAGE
# ... DEFINE SIMULATION PARAMETERS
t_max = 3000. # (fs)
t_num = 2**14 # (-)
z_max = 8.0e3 # (micron)
z_num = 10000 # (-)
z_skip = 10 # (-)
n2 = 3.0e-8 # (micron^2/W)
wS = 1.884 # (rad/fs)
tS = 10.0 # (fs)
NS = 10. # (-)
# ... PROPAGGATION CONSTANT
beta_fun = define_beta_fun_NLPM750()
pc = PropConst(beta_fun)
# ... COMPUTATIONAL DOMAIN, MODEL, AND SOLVER
grid = Grid( t_max = t_max, t_num = t_num, z_max = z_max, z_num = z_num)
model = FMAS_S_R(w=grid.w, beta_w=pc.beta(grid.w), n2 = n2)
solver = IFM_RK4IP( model.Lw, model.Nw)
# -- SET UP INITIAL CONDITION
A0 = NS*np.sqrt(np.abs(pc.beta2(wS))*model.c0/wS/n2)/tS
Eps_0w = AS(np.real(A0/np.cosh(grid.t/tS)*np.exp(1j*wS*grid.t))).w_rep
solver.set_initial_condition( grid.w, Eps_0w)
# -- PERFORM Z-PROPAGATION
solver.propagate( z_range = z_max, n_steps = z_num, n_skip = z_skip)
# -- SHOW RESULTS
utz = change_reference_frame(solver.w, solver.z, solver.uwz, pc.vg(wS))
plot_evolution( solver.z, grid.t, utz,
t_lim = (-100,100), w_lim = (0.5,8.), DO_T_LOG = True)
def main():
# -- INITIALIZATION STAGE
# ... DEFINE SIMULATION PARAMETERS
t_max = 3500. / 2 # (fs)
t_num = 2**14 # (-)
z_max = 50.0e3 # (micron)
z_num = 100000 # (-)
z_skip = 100 # (-)
c0 = 0.29979 # (micron/fs)
n2 = 1. # (micron^2/W) FICTITIOUS VALUE ONLY
wS = 2.32548 # (rad/fs)
tS = 50.0 # (fs)
NS = 3.54 # (-)
# ... PROPAGGATION CONSTANT
beta_fun = define_beta_fun_fluoride_glass_AD2010()
pc = PropConst(beta_fun)
chi = (8. / 3) * pc.beta(wS) * c0 / wS * n2
# ... COMPUTATIONAL DOMAIN, MODEL, AND SOLVER
grid = Grid(t_max=t_max, t_num=t_num, z_max=z_max, z_num=z_num)
model = BMCF(w=grid.w, beta_w=pc.beta(grid.w), chi=chi)
solver = IFM_RK4IP(model.Lw, model.Nw)
# -- SET UP INITIAL CONDITION
LD = tS * tS / np.abs(pc.beta2(wS))
A0 = NS * np.sqrt(8 * c0 / wS / n2 / LD)
Eps_0w = AS(np.real(A0 / np.cosh(grid.t / tS) *
np.exp(1j * wS * grid.t))).w_rep
solver.set_initial_condition(grid.w, Eps_0w)
# -- PERFORM Z-PROPAGATION
solver.propagate(z_range=z_max, n_steps=z_num, n_skip=z_skip)
# -- SHOW RESULTS
utz = change_reference_frame(solver.w, solver.z, solver.uwz, pc.vg(wS))
plot_evolution(solver.z,
grid.t,
utz,
t_lim=(-500, 500),
w_lim=(-10., 10.),
DO_T_LOG=True,
ratio_Iw=1e-15)
def main():
# -- DEFINE SIMULATION PARAMETERS
# ... COMPUTATIONAL DOMAIN
t_max = 2000. # (fs)
t_num = 2**13 # (-)
z_max = 1.0e6 # (micron)
z_num = 10000 # (-)
z_skip = 10 # (-)
n2 = 3.0e-8 # (micron^2/W)
c0 = 0.29979 # (fs/micron)
lam0 = 0.860 # (micron)
w0_S = 2 * np.pi * c0 / lam0 # (rad/fs)
t0_S = 20.0 # (fs)
w0_DW = 2.95 # (rad/fs)
t0_DW = 70.0 # (fs)
t_off = -250.0 # (fs)
sFac = 0.75 # (-)
beta_fun = define_beta_fun_poly_NLPM750()
pc = PropConst(beta_fun)
# -- INITIALIZATION STAGE
grid = Grid(t_max=t_max, t_num=t_num, z_max=z_max, z_num=z_num)
model = FMAS_S_R(w=grid.w, beta_w=pc.beta(grid.w), n2=n2)
solver = IFM_RK4IP(model.Lw, model.Nw, user_action=model.claw)
# -- SET UP INITIAL CONDITION
t = grid.t
A0 = np.sqrt(abs(pc.beta2(w0_S)) * c0 / w0_S / n2) / t0_S
A0_S = A0 / np.cosh(t / t0_S) * np.exp(1j * w0_S * t)
A0_DW = sFac * A0 / np.cosh((t - t_off) / t0_DW) * np.exp(1j * w0_DW * t)
Eps_0w = AS(np.real(A0_S + A0_DW)).w_rep
solver.set_initial_condition(grid.w, Eps_0w)
solver.propagate(z_range=z_max, n_steps=z_num, n_skip=z_skip)
# -- SHOW RESULTS
utz = change_reference_frame(solver.w, solver.z, solver.uwz, pc.vg(w0_S))
plot_evolution(solver.z,
grid.t,
utz,
t_lim=(-1200, 1200),
w_lim=(1.8, 3.2))
###############################################################################
# The figure below shows the dynamic evolution of the pulse in the time domain
# (top subfigure) and in the frequency domain (center subfigure). The subfigure
# at the bottom shows the conservation law (c-law) given by the normalized
# photon number variation
#
# .. math::
# \delta_{\rm{Ph}}(z) = \frac{ C_p(z)-C_p(0)}{C_p(0)}
#
# as function of the proapgation coordinate :math:`z`. For the considered
# discretization of the computational domain the normalized photon number
# variation is of the order :math:`\delta_{\rm{Ph}}\approx 10^{-7}` and thus
# very small. The value can be still decreased by decreasing the stepsize
# :math:`\Delta z`.
utz = change_reference_frame(solver.w, solver.z, solver.uwz, pc.vg(w0))
plot_claw(solver.z,
grid.t,
utz,
solver.ua_vals,
t_lim=(-25, 125),
w_lim=(0.5, 4.5))
###############################################################################
# **References:**
#
# [AD2010] Sh. Amiranashvili, A. Demircan, Hamiltonian structure of propagation
# equations for ultrashort optical pulses, Phys. Rev. E 10 (2010) 013812,
# http://dx.doi.org/10.1103/PhysRevA.82.013812.
#
grid = Grid(
t_max=4500., # (fs)
t_num=2**14 # (-)
)
model = ZBLAN(grid.w, fR=0.0)
###############################################################################
# To visually assess the group-velocity (GV) and group-velocity dispersion
# (GVD) of the propagation constant in the relevant angular frequency range we
# use the convenience class `PropConst` and pre-implemented plotting functions
# that are implemented in module `tools`
w = grid.w[np.logical_and(grid.w > 0.5, grid.w < 5.)]
pc = PropConst(model.beta_fun)
plot_details_prop_const(w, pc.vg(w), pc.beta2(w))
###############################################################################
# Next, we prepare the corresponding initial condition, which is well described
# in Ref. [3]. It consists of a fundamental soliton with duration
# :math:`t_{\rm{S}}=25.2\,\mathrm{fs}` and center frequency
# :math:`\omega_{\rm{S}}=0.4709\,\mathrm{rad/fs}`, and a dispersive wave with
# duration :math:`t_{\rm{DW}}=100\,\mathrm{fs}` and angular frequency
# :math:`\omega_{\rm{DW}}=2.6177\,\mathrm{rad/fs}`. Both pulses exhibit an
# amplitude ratio of :math:`A_{\rm{DW}}/A_{\rm{S}}=0.566`, and the soliton is
# launched with deltay :math:`t_{\rm{off}}=450\,\mathrm{fs}`.
wS, tS = 0.4709, 25.2 # (rad/fs), (fs)
wDW, tDW = 2.6177, 100. # (rad/fs), (fs)
t_off = -450. # (fs)
rDW = 0.566 # (-)
p = np.poly1d((16.89475, 0.0, -319.13216, 0.0, 34.82210, 0.0, -0.992495,
0.0, 0.0010671)[::-1])
q = np.poly1d((1.00000, 0.0, -702.70157, 0.0, 78.28249, 0.0, -2.337086,
0.0, 0.0062267)[::-1])
c = 0.29979 # (micron/fs)
return lambda w: (1 + p(w) / q(w)) * w / c
# -- WRAP PROPAATION CONSTANT
beta_fun = get_beta_fun_ESM()
pc = PropConst(beta_fun)
# -- FIND ZERO DISPERSION POINT
w_Z = pc.find_root_beta2(1.3, 2.2)
print("w_Z = %lf rad/fs" % (w_Z))
# -- FIND GV MATCHED PARTNER FREQUENCY
w_S = 1.5 # (rad/fs)
w_GVM = pc.find_match_beta1(w_S, w_Z, 2.5)
print("w_GVM = %lf rad/fs " % (w_GVM))
# -- GV MISMATCH FOR S AND DW1
w_DW1 = 2.06 # (rad/fs)
dvg = pc.vg(w_DW1) - pc.vg(w_S)
print("dvg = %lf micron/fs" % (dvg))
# -- LOCAL EXPANSION COEFFICIENTS
betas = pc.local_coeffs(w_S, n_max=4)
for n, bn in enumerate(betas):
print("b_%d = %lf fs^%d/micron" % (n, bn, n))
# cooresponding instance of the `PropConst` convenience class, wrapping the
# function `beta_fun`.
beta_fun = define_beta_fun_NLPM750()
pc = PropConst(beta_fun)
###############################################################################
# We then visually assess the group-velocity (GV) and group-velocity dispersion
# (GVD) of the propagation constant in the angular frequency range
# :math:`\omega \in [1.2,3.2]~\mathrm{rad/fs}`. GV and GVD are implemented by
# the class methods `vg`, and `beta2`, respectively. To generate a quick plot
# of both, the GV and GVD, we use the function `plot_details_prop_const`, which
# is defined in module `tools`.
w = np.linspace(1.3, 3.2, 200)
plot_details_prop_const(w, pc.vg(w), pc.beta2(w))
###############################################################################
# Finding zero-dispersion points
# ------------------------------
#
# A quick visual assessment of the GVD in the bottom subfigure allows to
# roughly locate the first zero-dispersion point within the angular frequency
# interval :math:`[1.4,1.7]~\mathrm{rad/fs}`. The second zero-dispersion point
# surely falls into the interval :math:`[2.2,2.5]~\mathrm{rad/fs}`. From these
# rough estimates we can determine the exact roots of :math:`\beta_2` as shown
# below:
w_Z1 = pc.find_root_beta2(1.4, 1.7)
w_Z2 = pc.find_root_beta2(2.2, 2.5)