def __init__(self, L=100.0, W=1.0, eta=0.0, N=2.5, theta=0.0, **base_kwargs):
"""Exceptional Point (EP) waveguide class.
Copies methods and variables from the Base class and adds new
parameters.
Additional parameters:
----------------------
L, W: float
Waveguide length/width
N: float
Number of open modes
eta: float
Dissipation coefficient
theta: float
Phase difference between upper and lower boundary
"""
Base.__init__(self, T=L, **base_kwargs)
self.L = L
self.W = W
self.N = N
self.eta = eta
self.theta = theta
self.k = lambda n: np.sqrt(N**2 - n**2)*np.pi/W
self.kF = N*np.pi/W
def __init__(self, R=0.05, gamma=2.0, **kwargs):
"""Exceptional Points (EP) optomechanics class.
Copies methods and variables from Base class.
Additional parameters:
----------------------
R: float
Trajectory radius around the EP.
gamma: float
Relative loss between states |1> and |2>.
"""
Base.__init__(self, **kwargs)
self.R = R
self.gamma = gamma
self.x_EP = 0.0
self.y_EP = gamma/2.
def plot_flip_error():
"""
Plot the flip-error measures R1 and R2 as a function of the
cycle time T (loop duration).
"""
##
# plot ratios b_1/a_1(T)
##
params = getParamList(a1 = 0.0, a2 = 0.0, b1 = 0.8, b2 = 0.8,
c1 = 0.2, c2 = 0.2, p = 0.0)
params = getParamList(a2 = -0.3, b1 = 0.45, b2 = 0.9,
c1 = 0.1, c2 = 0.1, p = 0.0)
Tmax = 20
TN = 50
Trange = np.linspace(0.01, Tmax, TN)
R1 = np.zeros((TN,), complex)
R2 = np.zeros((TN,), complex)
for n, T in enumerate(Trange):
print "T = ", T
##
# flip-error R1
##
h = Base(T=T, loop_type=1, init_state='a',
init_cond=params, loop_direction='-')
_, psi_a, psi_b = h.solve_ODE()
R1[n] = psi_b[-1]/psi_a[-1]
##
# flip-error R2
##
h = Base(T=T, loop_type=1, init_state='b',
init_cond=params, loop_direction='-')
_, psi_a, psi_b = h.solve_ODE()
R2[n] = psi_a[-1]/psi_b[-1]
xlim(0, Tmax)
ylim(1e-2, 1e3)
semilogy(Trange, abs(R1), "ro-")
semilogy(Trange, abs(R2), "go-")
semilogy(Trange, abs(R1*R2), "ko-")
show()
def __init__(self, **kwargs):
"""Copy methods and variables from Base class."""
Base.__init__(self, **kwargs)
