# Chapter13 - Fiber-optic sensors¶

## Example 13.1: Page 327¶

In [2]:
from numpy import arange
%matplotlib inline
from matplotlib.pyplot import plot, subplot, title, xlabel, ylabel, show
#plot
lod=[0, 20, 40, 60, 80, 100, 160] #in micro meter
slong=[1.0, 0.95, 0.92, 0.89, 0.86, 0.83, 0.80]
lad=[0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100] #in micro meter
slat=[0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0]
add=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
sang=[0, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, .12]

t=arange(0,201,20)
s1=arange(1.0,0.7,-0.03)
#subplot(131)
plot(t,s1)
title("Variation of Slong as a function of delta x (with deltay=fi and delta theta=fi) ")
xlabel("Longitudinal displacement delta x (micro meter)")
ylabel("Slong (normalised)")
show()
t1=arange(0,101,10)
s2=arange(1,-0.1,-0.1)

#subplot(132)
plot(t1,s2)##
title("Variation of Slat as a function of delta y (with deltax=fi and delta theta=fi) ")
xlabel("Lateral displacement delta y (micro meter)")
ylabel("Slat (normalised)")
show()
t2=arange(0,11,1)
s3=arange(1.0,0.7,-0.03)
#subplot(133)
plot(t2,s3)##
title("Variation of Sang as a function of delta theta (with deltax=fi and deltay=fi) ")
xlabel("Angular displacement delta theta (deg)")
ylabel("Sang (normalised)")
show()


## Example 13.2: Page 332¶

In [3]:
from math import sqrt, pi
#phase change
#given data :
n=1.45## index of core
a=10**-5## in C**-1
b=5.1*10**-7## in C**-1
lamda=.633*10**-6## in m
# formula:- (1/L)*(del_fi/del_T)=((2*PI)/lamda)[(n/L)*(del_L/del_T)+(del_n/del_T)]
#let we assume a=del_n/del_T, b=(1/L)*(del_L/del_T), c=(1/L)*(del_fi/del_T)
c=((2*pi)/lamda)*((n*b)+a)#
print "phase change = %0.2f rad/m°C"%c

phase change = 106.60 rad/m°C


## Example 13.3: Page 335¶

In [4]:
from math import pi,sqrt
#phase shift
#given data :
L=500## in m
D=0.1##in m

phase shift, del_fi = 8.99e-05 rad