Example 6 added - XPM

examples/example_crossphasemodulation_6.py

@@ -20,17 +20,17 @@ import matplotlib.pyplot as plt
 
 
 # Define network elements
-gp       = pypho_setup(nos = 4*16, sps = 1*128, symbolrate = 10e9)
+gp       = pypho_setup(nos = 8, sps = 256, symbolrate = 10e9)
 bitsrc   = pypho_bits(glova = gp, nob = gp.nos, pattern = 'singlepulse') # Set pattern = "singlepulse"
 esigsrc  = pypho_signalsrc(glova = gp, pulseshape = 'gauss_rz' , fwhm = 0.33)
-sig_f0   = pypho_cwlaser(glova = gp, power = 3, Df = 0,  teta = 1*np.pi/4.0)
-sig_f1   = pypho_lasmod(glova = gp, power = 0, Df = 500, teta = 1*np.pi/1.0)
-filter_f0 = pypho_optfi(glova = gp, Df = 0, B = 50)
-SSMF     = pypho_fiber(glova = gp, l = 80,  D = 9.0,   S = 0.0, alpha = 0.2, gamma = 1.4, phi_max = .1)
+sig_f0   = pypho_cwlaser(glova = gp, power = -20, Df = 0,  teta =1*np.pi/4.0)
+sig_f1   = pypho_lasmod(glova = gp, power = -10, Df = 500, teta = 0*np.pi/1.0)
+filter_f0 = pypho_optfi(glova = gp, Df = 0, B = 150)
+SSMF     = pypho_fiber(glova = gp, l = 10e3,  D = 0.0,   S = 0.0, alpha = 0.2, gamma = 1.4, phi_max = .001)
 
 # Simulation
 
-# Define wavelength channel
+# Define wavelength channels
 
 E_f0    = sig_f0()                                              
 
@@ -47,20 +47,20 @@ E_Tx = copy.deepcopy(E)
 # Plot Spectrum Input signals
 plt.figure(1)
 plt.subplot(2, 1, 1)
-plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][0]   )**2))), 'r')
-plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][1]   )**2))), 'g:')
+plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][0]   )**2))), 'r', label='X-Pol')
+plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][1]   )**2))), 'g:', label='Y-Pol')
 plt.title("Input spectrum", loc='left')
 plt.ylabel('Spec. density');
 plt.grid(True)
-
+plt.legend()
 # Fiber transmission
        
 E = SSMF(E = E)    
 
 # Plot Spectrum Output signals
 plt.subplot(2, 1, 2)
-plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][0]   )**2))), 'r')
-plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][1]   )**2))), 'g:')
+plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][0]   )**2))), 'r', label='X-Pol')
+plt.plot((gp.freqax-gp.f0)*1e-9, np.log10(abs(fftshift(fft(E[0]['E'][1]   )**2))), 'g:', label='Y-Pol')
 plt.title("Output spectrum", loc='left')
 plt.ylabel('Spec. density'); plt.xlabel('Frequency deviation [GHz]');
 plt.grid(True)
@@ -68,23 +68,39 @@ plt.grid(True)
 
 # Calculate phase shift
 L_eff = (1-np.exp(-SSMF.l*SSMF.alpha))/(SSMF.alpha)
-phi_x_max = - (np.max(np.abs(E_Tx[0]['E'][0])**2) + 2.0/3.0* np.max(np.abs(E_Tx[0]['E'][1])**2))* L_eff * SSMF.gamma *1e-3
-phi_y_max = - (np.max(np.abs(E_Tx[0]['E'][1])**2) + 2.0/3.0* np.max(np.abs(E_Tx[0]['E'][0])**2))* L_eff * SSMF.gamma *1e-3
+phi_XPM_x_max = - 2*(np.max(np.abs(E_f1[0]['E'][0])**2) + 2.0/3.0* np.max(np.abs(E_f1[0]['E'][1])**2))* L_eff * SSMF.gamma *1e-3
+phi_XPM_y_max = - 2*(np.max(np.abs(E_f1[0]['E'][1])**2) + 2.0/3.0* np.max(np.abs(E_f1[0]['E'][0])**2))* L_eff * SSMF.gamma *1e-3
+
+phi_SPM_x_max = - (np.max(np.abs(E_f0[0]['E'][0])**2) + 2.0/3.0* np.max(np.abs(E_f0[0]['E'][1])**2))* L_eff * SSMF.gamma *1e-3
+phi_SPM_y_max = - (np.max(np.abs(E_f0[0]['E'][1])**2) + 2.0/3.0* np.max(np.abs(E_f0[0]['E'][0])**2))* L_eff * SSMF.gamma *1e-3
 
 print 'L_eff = ', L_eff
-print 'phi_x_max = ', phi_x_max
-print 'phi_y_max = ', phi_y_max
+print 'phi_XPM_x_max = ', phi_XPM_x_max
+print 'phi_XPM_y_max = ', phi_XPM_y_max
+print 'phi_SPM_x_max = ', phi_SPM_x_max
+print 'phi_SPM_y_max = ', phi_SPM_y_max
+print 'phi_x_max = phi_XPM_x_max + phi_SPM_x_max', phi_XPM_x_max + phi_SPM_x_max
+print 'phi_y_max = phi_XPM_y_max + phi_SPM_y_max', phi_XPM_y_max + phi_SPM_y_max
 
 # Plot power of both pol axis as function of transmission distance
+
+E = filter_f0(E)
+
 plt.figure(2)
 
-plt.subplot(2, 1, 2)
-plt.ylabel('$10log |E_y|^2$'); plt.xlabel('Transmission distance [m]');
-plt.ylim((-120, 10))
-plt.grid(True)
 plt.subplot(2, 1, 1)
-plt.ylabel('$10log |E_y|^2$');
-plt.ylim((-120, 10)) 
+plt.ylabel('$|E|^2$'); plt.xlabel('Transmission distance [m]');
+plt.plot(gp.timeax*1.0e12, np.abs(E_f1[0]['E'][0])**2, 'r', label='$E_x Pulse$')
+plt.plot(gp.timeax*1.0e12, np.abs(E_f1[0]['E'][1])**2, 'g', label='$E_y Pulse$')
+plt.plot(gp.timeax*1.0e12, np.abs(E_f0[0]['E'][0])**2, 'r:', label='$E_x cw@1550nm$')
+plt.plot(gp.timeax*1.0e12, np.abs(E_f0[0]['E'][1])**2, 'g:', label='$E_y cw@1550nm$')
+
+
 plt.grid(True)
-plt.legend()
+plt.subplot(2, 1, 2)
+plt.plot(gp.timeax*1.0e12, np.angle(E[0]['E'][0]), 'r', label='$E_x$')
+plt.plot(gp.timeax*1.0e12, np.angle(E[0]['E'][1]), 'g', label='$E_y$')
+plt.ylabel('$phase(E_x)$');
+plt.grid(True)
+
 plt.show()
\ No newline at end of file