1. Optical Networks – Tutorial Lecture #1

2. Instructor information
Name: Thuraya Alrumaih
Office #: 0,701,39
Office hours:
SUN: 9-10 A.M.
TUE: 9-10 A.M.
THU: 9-10 A.M.
Blog :
Networks and Communication Department

3. Grades Grade Due week Evaluation %5 Every week Assignment
Participation attendance
(30-March)
Week 10
Quiz
15%
Total
Networks and Communication Department

4. Overview : •  Light Characteristics •  Light Properties •  Reflection and Refraction

5. Light Characteristics •  Particle Characteristics –  Light has energy –  Photons are the smallest quantity of monochromatic light –  The energy of a photon is described by: E= hf • (h= x 10 −34 joule.sec) and f is the frequency of light –  The relationship between frequency and speed: v=c/λ • Speed of light changes as it enters denser materials •  Wave Characteristics –  Described by a series of equations

6. Example #1 A light wave with λ= 1 µm c = 3 ×10^8m/sec. v =?
c = 3x10^8
v = c/λ
v = 3x10^8 / 1x10^-6
=> 3x10^14 m/s

7. Example #2 Find the energy of a photon travelling with 200 THz frequency. Given that h is Planck’s constant = x10^-34.
E= hf
E =(6.6256x10^-34)*(200x10^12)
=> x10^-19 Joule

8. Light Properties •  Light is electromagnetic radiation – Impacted by many parameters: reflection, refraction, loss, polarization, scattering, etc. •  Light of a single frequency is termed monochromatic •  Any electromagnetic wave is governed by a series of equations

9. Wave Velocity Equation: Phase Velocity
•  The wave moves a distance of one wavelength λ in one period T
•  From this, we can calculate the phase velocity denoted vp.
- (It is how fast the peaks and valleys move.)
Vp = λƒ
= λ/T
Reminder:
ƒ= 1/T

10. Reflection and Refraction •  When light finds a surface separating two media (air and water, for example), a beam gets reflected and another gets refracted (transmitted). -Law of reflection: the angle of incidence θ1 = θ2 the angle of reflection . -Law of refraction: n2 sinθ2 = n1 sinθ1 (Snell’s law.) n is the index of refraction of the medium. In vacuum, n=1. In air, n~1. In all other media, n>1.

11. Example #4 Water has n=1.33. How much does a beam incident at 45 refracts?
n2 sinθ2 = n1 sinθ1
sinθ2 = n1/n2 sinθ1
1/1.33 sin 45
.53165
Θ2=Sin^-1 (.53165) = 32◦