# Chapter11 - Wavelength-division multiplexing¶

## Example 11.1 : Page 277¶

In :
from __future__ import division
from math import sqrt, pi, asin
#interaction length
po=1##assume
p1=po/2##
p2=p1##
kl=asin(sqrt(p1))##in degree
print "interaction length = %0.3f "%kl
#answer is in the form of pi in the textbook

interaction length = 0.785


## Example 11.2 : Page 279¶

In :
from __future__ import division
from math import sqrt, pi, asin
#position
a=8.2##in micro meter
n1=1.45##
n2=1.446##
h1=1.31##in micro meter
h2=1.55##/in micro meter
v1=((2*pi*a*sqrt(n1**2-n2**2))/h1)##
v2=((2*pi*a*sqrt(n1**2-n2**2))/h2)##
db=2.439##
Del=5.5096*10**-3##
k1=1.0483##mm**-1##
k2=1.2839#/m**-1
l1=((pi)/(4*k1))##in mm
l2=((pi)/(4*k2))##in mm
print "output port positioned at %0.4f"%(l1)," mm with respect to the input port will gather signals at h1=1310nm"
print "output port positioned at %0.4f"%(l2)," mm with respect to the input port will gather signals at h1=1550nm"

output port positioned at 0.7492  mm with respect to the input port will gather signals at h1=1310nm
output port positioned at 0.6117  mm with respect to the input port will gather signals at h1=1550nm


## Example 11.4 : Page 286¶

In :
# ARRAYED GUIDE
#given data
c=3*10**8#
lamda_c=1.55*10**-6## in m
vc=c/lamda_c#
n=16## number of channel
f=100*10**9## in Hz
delV_FSR=n*f#
m=round(vc/delV_FSR)#
print "required order of the arrayed waveguide, = ",m

required order of the arrayed waveguide, =  121.0