test axicon added

LgBeams become LgBasis

Author: seghil

opencavity/Test_files/test_axicon.py

@@ -0,0 +1,44 @@
+# -*- coding: utf-8 -*-
+"""
+@author: Mohamed
+"""
+
+# beam propagation through an axicon 
+
+from opencavity.beams import HgBasis
+from opencavity.propagators import FresnelProp
+import numpy as np
+import matplotlib.pylab as plt
+
+# generate the beam 
+
+wavelength=1
+waist=200 #wasit of the laser beam 
+H=HgBasis(wavelength,waist,waist) #creating the Hermite-Gauss basis with initial waist equals to 100 microns
+z0=1e-8
+
+x=np.linspace(-500, 500,500); # abscissa 
+tem00=H.generate_hg(0,0, x,0, z0) # the TEM00 gaussian beam for y=0 so no y component and for z=0 so at the waist.
+#plt.plot(x,np.abs(tem00)**2,'r')
+
+k=2*np.pi/wavelength
+theta=0.5*3.14/180;# 0.5 deg axicon (induced phase not real angle)
+                    # theta can be approximated : (axicon_index-1)*axicon_base_angle
+T_axicon=np.exp((+1j*k)*theta*(np.sign(x))*x)
+
+L=10*1e3;
+M=np.array([[1, L],[0, 1]]);
+
+prop=FresnelProp(wavelength)
+prop.set_start_beam(tem00,x)
+prop.set_ABCD(M)
+prop.apply_mask1D(T_axicon)
+prop.propagate1D_ABCD()
+prop.show_result_beam('intensity')
+plt.show()
+
+#plot at several successive planes 
+prop.yz_prop_chart(3e3,50e3,100,2*x)
+plt.set_cmap('hot')
+prop.show_prop_yz()
+plt.show()

opencavity/beams.py

@@ -100,7 +100,7 @@ def generate_hg(self,m,p,x,y,z):
         y=y1*y2*y3*y4
         return y               
 
-class LGbeam(object):
+class LgBasis(object):
     '''
     Generation of Hermite Gauss beams 
     '''