4 files changed, 56 insertions, 0 deletions
diff --git a/1535/CH12/EX12.1/Ch12Ex1.sci b/1535/CH12/EX12.1/Ch12Ex1.sci
new file mode 100755
index 000000000..65ab0eaef
--- /dev/null
+++ b/1535/CH12/EX12.1/Ch12Ex1.sci
@@ -0,0 +1,16 @@
+// Scilab Code Ex12.1: Parameters of step index fibre : Page-271 (2010)
+n1 = 1.43;    // Refractive index of fibre core
+n2 = 1.4;    // Refractive index of fibre cladding
+// As sin (alpha_c) = n2/n1, solving for alpha_c
+alpha_c = asind(n2/n1);    // Critical angle for optical fibre, degrees
+// AS cos(theta_c) = n2/n1, solving for theta_c
+theta_c = acosd(n2/n1);    // Critical propagation angle for optical fibre, degrees
+NA = sqrt(n1^2 - n2^2);    // Numerical aperture for optical fibre
+printf("\nThe critical angle for optical fibre = %5.2f degrees", alpha_c);
+printf("\nThe critical propagation angle for optical fibre = %5.2f degrees", theta_c);
+printf("\nNumerical aperture for optical fibre = %4.2f", NA);
+
+// Result
+// The critical angle for optical fibre = 78.24 degrees
+// The critical propagation angle for optical fibre = 11.76 degrees
+// Numerical aperture for optical fibre = 0.29 
+\ No newline at end of file
diff --git a/1535/CH12/EX12.2/Ch12Ex2.sci b/1535/CH12/EX12.2/Ch12Ex2.sci
new file mode 100755
index 000000000..0fde37fe2
--- /dev/null
+++ b/1535/CH12/EX12.2/Ch12Ex2.sci
@@ -0,0 +1,16 @@
+// Scilab Code Ex12.2: Parameters of optical fibre : Page-271 (2010)
+n1 = 1.45;    // Refractive index of fibre core
+n2 = 1.4;    // Refractive index of fibre cladding
+NA = sqrt(n1^2 - n2^2);    // Numerical aperture for optical fibre
+// As sin(theta_a) = sqrt(n1^2 - n2^2), solving for theta_a
+theta_a = asind(sqrt(n1^2 - n2^2));    // Half of acceptance angle of optical fibre, degrees
+theta_accp = 2*theta_a;    // Acceptance angle of optical fibre
+Delta = (n1 - n2)/n1;    // Relative refractive index difference
+printf("\nNumerical aperture for optical fibre = %5.3f", NA);
+printf("\nThe acceptance angle of optical fibre = %4.1f degrees", theta_accp);
+printf("\nRelative refractive index difference = %5.3f", Delta);
+
+// Result
+// Numerical aperture for optical fibre = 0.377
+// The acceptance angle of optical fibre = 44.4 degrees
+// Relative refractive index difference = 0.034 
+\ No newline at end of file
diff --git a/1535/CH12/EX12.3/Ch12Ex3.sci b/1535/CH12/EX12.3/Ch12Ex3.sci
new file mode 100755
index 000000000..823e6d152
--- /dev/null
+++ b/1535/CH12/EX12.3/Ch12Ex3.sci
@@ -0,0 +1,14 @@
+// Scilab Code Ex12.3: Numerical aperture and acceptance angle of step index fibre : Page-271 (2010)
+n1 = 1.55;    // Refractive index of fibre core
+n2 = 1.53;    // Refractive index of fibre cladding
+n0 = 1.3;    // Refractive index of medium
+NA = sqrt(n1^2 - n2^2);    // Numerical aperture for optical fibre
+// n0*sin(theta_a) = sqrt(n1^2 - n2^2) = NA, solving for theta_a
+theta_a = asind(sqrt(n1^2 - n2^2)/n0);    // Half of acceptance angle of optical fibre, degrees
+theta_accp = 2*theta_a;    // Acceptance angle of optical fibre
+printf("\nNumerical aperture for step index fibre = %5.3f", NA);
+printf("\nThe acceptance angle of step index fibre = %2d degrees", theta_accp);
+
+// Result
+// Numerical aperture for step index fibre = 0.248
+// The acceptance angle of step index fibre = 22 degrees 
+\ No newline at end of file
diff --git a/1535/CH12/EX12.5/Ch12Ex5.sci b/1535/CH12/EX12.5/Ch12Ex5.sci
new file mode 100755
index 000000000..adac22875
--- /dev/null
+++ b/1535/CH12/EX12.5/Ch12Ex5.sci
@@ -0,0 +1,10 @@
+// Scilab Code Ex12.5: Output power in fibre optic communication : Page-272 (2010)
+alpha = 2;    // Power loss through optical fibre, dB/km
+P_in = 500;    // Poer input of optical fibre, micro-watt
+z = 10;    // Length of the optical fibre, km
+// As alpha = 10/z*log10(P_in/P_out), solving for P_out
+P_out = P_in/10^(alpha*z/10);    // Output power in fibre optic communication, W
+printf("\nThe output power in fibre optic communication = %1d micro-watt", P_out);
+
+// Result
+// The output power in fibre optic communication = 5 micro-watt 
+\ No newline at end of file