Exemplo n.º 1
0
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)
Exemplo n.º 2
0
def main():

    t_max = 2000.  # (fs)
    t_num = 2**14  # (-)
    z_max = 0.06e6  # (micron)
    z_num = 25000  # (-)
    z_skip = 50  # (-)
    chi = 1.0  # (micron^2/W)
    c0 = 0.29979  # (micron/fs)

    # -- PROPAGATION CONSTANT
    beta_fun = define_beta_fun()
    pc = PropConst(beta_fun)

    # -- INITIALIZE DATA-STRUCTURES AND ALGORITHMS
    grid = Grid(t_max=t_max, t_num=t_num, z_max=z_max, z_num=z_num)
    model = FMAS(w=grid.w, beta_w=beta_fun(grid.w), chi=chi)
    solver = IFM_RK4IP(model.Lw, model.Nw, user_action=model.claw)

    # -- PREPARE INITIAL CONDITION AND RUN SIMULATION
    w01, t01, A01 = 1.178, 30.0, 0.0248892  # (rad/fs), (fs), (sqrt(W))
    w02, t02, A02 = 2.909, 30.0, 0.0136676  # (rad/fs), (fs), (sqrt(W))
    A_0t_fun = lambda t, A0, t0, w0: np.real(A0 / np.cosh(t / t0) * np.exp(
        1j * w0 * t))
    E_0t = A_0t_fun(grid.t, A01, t01, w01) + A_0t_fun(grid.t, A02, t02, w02)
    solver.set_initial_condition(grid.w, AS(E_0t).w_rep)
    solver.propagate(z_range=z_max, n_steps=z_num, n_skip=z_skip)

    # -- SHOW RESULTS IN MOVING FRAME OF REFERENCE
    v0 = 0.0749641870819  # (micron/fs)
    utz = change_reference_frame(solver.w, solver.z, solver.uwz, v0)
    plot_evolution(solver.z, grid.t, utz, t_lim=(-100, 150), w_lim=(0.3, 3.8))
Exemplo n.º 3
0
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)
Exemplo n.º 4
0
def main():

    t_max = 2000.           # (fs)
    t_num = 2**14           # (-)
    chi = 1.0               # (micron^2/W)  
    c0 = 0.29979            # (micron/fs)

    # -- PROPAGATION CONSTANT
    beta_fun = define_beta_fun()
    pc = PropConst(beta_fun)

    grid = Grid( t_max = t_max, t_num = t_num)
    model = FMAS(w=grid.w, beta_w = beta_fun(grid.w), chi = chi )
    solver = IFM_RK4IP( model.Lw, model.Nw, user_action = model.claw)

    # -- FUNDAMENTAL SOLITON INTITIAL CONDITION
    A_0t_fun = lambda t, A0, t0, w0: np.real(A0/np.cosh(t/t0)*np.exp(1j*w0*t))
    # ... FIRST SOLITON: PROPAGATE AND CLEAN-UP PRIOR TO COLLISION
    w01, t01, A01 = 1.2, 20.0,  0.0351187       # (rad/fs), (fs), (sqrt(W))
    z_max, z_num, z_skip = 0.06e6, 6000, 200    # (micron), (-), (-)
    A_0t_1 = A_0t_fun(grid.t, A01, t01, w01)
    solver.set_initial_condition( grid.w, AS(A_0t_1).w_rep)
    solver.propagate( z_range = z_max, n_steps = z_num, n_skip = z_skip)
    A_0t_1_f = np.real(
                 np.where(
                    np.logical_and(grid.t>-15., grid.t<273.0),
                    solver.utz[-1],
                    0j
                 )
               )
    solver.clear()

    # ... SECOND SOLITON: PROPAGATE AND CLEAN-UP PRIOR TO COLLISION
    w02, t02, A02 = 2.96750, 15.0, 0.0289073    # (rad/fs), (fs), (sqrt(W))
    z_max, z_num, z_skip = 0.06e6, 6000, 200    # (micron), (-), (-)
    A_0t_2 = A_0t_fun(grid.t-800., A02, t02, w02)
    solver.set_initial_condition( grid.w, AS(A_0t_2).w_rep)
    solver.propagate( z_range = z_max, n_steps = z_num, n_skip = z_skip)
    A_0t_2_f = np.real(
                 np.where(
                    np.logical_and(grid.t>435.0, grid.t<727.0),
                    solver.utz[-1],
                    0j
                 )
               )
    solver.clear()

    # -- LET CLEANED-UP SOLITONS COLLIDE
    z_max, z_num, z_skip = 0.22e6, 50000, 100   # (micron), (-), (-)
    solver.set_initial_condition( grid.w, AS( A_0t_1_f + A_0t_2 ).w_rep)
    solver.propagate( z_range = z_max, n_steps = z_num, n_skip = z_skip)

    # -- SHOW RESULTS IN MOVING FRAME OF REFERENCE
    v0 = 0.0749879876745 # (micron/fs)
    utz = change_reference_frame(solver.w, solver.z, solver.uwz, v0)
    plot_evolution( solver.z, grid.t, utz,
        t_lim = (-1400,1400), w_lim = (0.3,3.8), DO_T_LOG=False)
Exemplo n.º 5
0
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)
Exemplo n.º 6
0
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))
Exemplo n.º 7
0
###############################################################################
# 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.
#