14 files changed, 148 insertions, 0 deletions
diff --git a/3543/CH3/EX3.1/EX3_1.png b/3543/CH3/EX3.1/EX3_1.png
new file mode 100644
index 000000000..4409fbc03
--- /dev/null
+++ b/3543/CH3/EX3.1/EX3_1.png
diff --git a/3543/CH3/EX3.1/Ex3_1.sce b/3543/CH3/EX3.1/Ex3_1.sce
new file mode 100644
index 000000000..2aa813430
--- /dev/null
+++ b/3543/CH3/EX3.1/Ex3_1.sce
@@ -0,0 +1,27 @@
+//Calculation of barrier potential
+// Example 3.1 
+// Page no 80
+clc;
+clear all;
+close;
+
+
+//Given data
+p=5;                        // Resistivity of p-region
+n=2;                        // Resistivity of n-region
+mu=3900;
+k=0.026;                    //Boltzmann constant
+ni=2.5*10^13;              //Density of the electron hole pair
+e=1.6*10^-19;              //charge of electron
+ 
+//Barrier potential calculation
+r0=(1/p);          // Reflection at the fiber air interface 
+r1=(1/n);
+m=r1/(mu*e);
+p=6.5*10^14;       //Density of hole in p -region
+Vb=k*log(p*m/ni^2);
+
+//Displaying the result in command window
+printf("\n Barrier potential(in V) = %0.3f",Vb);
+
+// The answers vary due to round off error
diff --git a/3543/CH3/EX3.15/EX3_15.png b/3543/CH3/EX3.15/EX3_15.png
new file mode 100644
index 000000000..0f5d416d0
--- /dev/null
+++ b/3543/CH3/EX3.15/EX3_15.png
diff --git a/3543/CH3/EX3.15/Ex3_15.sce b/3543/CH3/EX3.15/Ex3_15.sce
new file mode 100644
index 000000000..8fe327db7
--- /dev/null
+++ b/3543/CH3/EX3.15/Ex3_15.sce
@@ -0,0 +1,19 @@
+// Example 3.15 
+// Calculation of external efficiency 
+// Page no 484
+
+clc;
+clear;
+close;
+
+//Given data
+ne1=0.20;       //Total efficiency 
+V=3;            // Voltage applied
+Eg=1.43;        // Bandgap energy
+
+// External efficiency
+ne=(ne1*Eg/V)*100;
+
+//Display result on command window
+printf("\n External efficiency of the device (in percentage)= %0.1f  ",ne);
+
diff --git a/3543/CH3/EX3.16/EX3_16.png b/3543/CH3/EX3.16/EX3_16.png
new file mode 100644
index 000000000..265b712dc
--- /dev/null
+++ b/3543/CH3/EX3.16/EX3_16.png
diff --git a/3543/CH3/EX3.16/Ex3_16.sce b/3543/CH3/EX3.16/Ex3_16.sce
new file mode 100644
index 000000000..7c0ee10eb
--- /dev/null
+++ b/3543/CH3/EX3.16/Ex3_16.sce
@@ -0,0 +1,23 @@
+// Example 3.16
+//  Calculation of ratio of threshold current densities
+// Page no 484
+
+clc;
+clear;
+close;
+
+// Given data
+To1=160;                     // Device temperature
+To2=55;                      // Device temperature
+T1=293;
+T2=353;
+J81=exp(T1/To1);            // Threshold current density 
+J21=exp(T2/To1);
+J82=exp(T1/To2);; 
+J22=exp(T2/To2);; 
+cd1=J21/J81;               // Ratio of threshold current densities
+cd2=J22/J82;
+
+//Display result on command window
+printf("\n Ratio of threshold current densities= %0.2f  ",cd1);
+printf("\n Ratio of threshold current densities= %0.2f  ",cd2);
diff --git a/3543/CH3/EX3.17/EX3_17.png b/3543/CH3/EX3.17/EX3_17.png
new file mode 100644
index 000000000..c91c9651e
--- /dev/null
+++ b/3543/CH3/EX3.17/EX3_17.png
diff --git a/3543/CH3/EX3.17/Ex3_17.sce b/3543/CH3/EX3.17/Ex3_17.sce
new file mode 100644
index 000000000..48e3c6aad
--- /dev/null
+++ b/3543/CH3/EX3.17/Ex3_17.sce
@@ -0,0 +1,18 @@
+// Example 3.17 
+//Computation of conversion efficiency 
+// Page no 484
+
+clc;
+clear;
+
+//Given data
+i=10*10^-6;            // Device current
+p=5;                  // Electrical power
+op=50 *10^-6;         // Optical power
+ip=5*10*10^-3;        // Input power
+
+//Conversion efficiency
+c=op/ip*100;              
+//Display result on command window
+printf("\n Conversion efficiency (in percentage)= %0.1f  ",c);
+
diff --git a/3543/CH3/EX3.18/EX3_18.png b/3543/CH3/EX3.18/EX3_18.png
new file mode 100644
index 000000000..bcc98b82a
--- /dev/null
+++ b/3543/CH3/EX3.18/EX3_18.png
diff --git a/3543/CH3/EX3.18/Ex3_18.sce b/3543/CH3/EX3.18/Ex3_18.sce
new file mode 100644
index 000000000..b684b3d3d
--- /dev/null
+++ b/3543/CH3/EX3.18/Ex3_18.sce
@@ -0,0 +1,20 @@
+// Example 3.18 
+// Calculation of total power emitted
+// Page no 485
+
+clc;
+clear;
+close;
+
+//Given data
+r=0.7;            // Emissivity
+r0=5.67*10^-8;    // Stephen's constant
+A=10^-4;          // Surface area
+T=2000;           // Temperature
+
+// Total power emitted
+P=r*r0*A*T^4;                     
+
+//Display result on command window
+printf("\n Total power emitted (Watts)= %0.1f  ",P);
+
diff --git a/3543/CH3/EX3.19/EX3_19.png b/3543/CH3/EX3.19/EX3_19.png
new file mode 100644
index 000000000..f8f19fcb2
--- /dev/null
+++ b/3543/CH3/EX3.19/EX3_19.png
diff --git a/3543/CH3/EX3.19/Ex3_19.sce b/3543/CH3/EX3.19/Ex3_19.sce
new file mode 100644
index 000000000..aa7403114
--- /dev/null
+++ b/3543/CH3/EX3.19/Ex3_19.sce
@@ -0,0 +1,20 @@
+// Example 3.19 
+// Computation of total energy
+// Page no 485
+
+clc;
+clear;
+close;
+
+//Given data
+h=6.63*10^-34;        // Planck constant
+v=5*10^14;            // Bandgap frequency of laser
+N=10^24;              // Population inversion density
+V=10^-5;              // Volume of laser medium
+
+// Total energy
+E=(1/2)*h*v*(N)*V;           
+
+//Display result on command window
+printf("\n Total energy (J)= %0.1f  ",E);
+
diff --git a/3543/CH3/EX3.20/EX3_20.png b/3543/CH3/EX3.20/EX3_20.png
new file mode 100644
index 000000000..20c3ad807
--- /dev/null
+++ b/3543/CH3/EX3.20/EX3_20.png
diff --git a/3543/CH3/EX3.20/Ex3_20.sce b/3543/CH3/EX3.20/Ex3_20.sce
new file mode 100644
index 000000000..201b2eb5a
--- /dev/null
+++ b/3543/CH3/EX3.20/Ex3_20.sce
@@ -0,0 +1,21 @@
+// Example 3.20 
+// Computation of pulse power
+// Page no 485
+
+clc;
+clear;
+close;
+
+// Given data
+L=0.1;               // Length of laser
+R=0.8;               // Mirror reflectance of end mirror
+E=1.7;               // Laser pulse energy
+c=3*10^8;            // Velocity of light
+t=L/((1-R)*c);         // Cavity life time
+
+// Pulse power
+p=E/t;                       
+
+//Display result on command window
+printf("\n Pulse power (W)= %0.0f  ",p);
+