8th sem subject ofc1st chapter notes by lohith kumar 11guee6018

2K6EC802: OPTICAL COMMUNICTION

Lectures: 4 Hours/Week Part-A | Chapter 1

Introduction: Evolution of fiber optic communication system. Advantages, Basic optical laws and definitions. Mode theory for circular waveguides, Single mode and Graded - index fiber Structures 7 hours.

1 st chapter related question and Answers

1. With help of a schematic diagram explain the optical fiber communication system?

2. Derive an expression for numerical aperture of the fiber?

3. Explain the common optical fiber cable structure?

4. With the Help of Snell’s law illustrate the phenomenon of Total internal reflections?

5. The refractive index of glass 1.5 and that of air is 1.0. Calculate the critical angle. Also calculate n and p for θt=20˚ and 45˚. The angle θI is define as

6. What is numerical aperture? Deduce an expression for the same?

7. Compare the following fibers. Single – Mode step index Multi – Mode step index Graded index and give the typical dimensions also.

8. Explain the concept of total internal reflection using snell’sLaw ?

9. Calculate the critical angle given that n1= 1.50 for glass and n2=1.00 for air also calculate n and p.

10. Explain briefly different types of optical fibers and their properties?

11. Define the following terms with figures Numerical aperture Acceptance angle Critical angle Step index refractive index profile Graded index refractive index profile

12. A step index fiber with a large core diameter compared with the wavelength of transmitted light has an acceptance angle in air of 22˚ and relative RI difference of 3%. Estimate the numerical aperture and the critical angle at the core – cladding interface for the fiber.

13. Compare the optical communication with satellite communication?

14.A step fiber has a normalized frequency V=28 at 1550nm wave length .if the core radius is 25µm. find the numerical aperture. Also calculate the number of modes M entering the fiber.

15. IIustratesnell’s law for a fiber with the refractive indexes of the core and cladding 1.48 and 1..46. Take one incidence angle each greater and lesser than critical angle of incidence Φc for the illustration.

16. A step index fiber has a normalized frequency V=28 at a 1550 nm wave length. If the core radius is 25µm,find the numerical

aperture. Also calculate the number of modes M entering the fiber.

1. With help of a schematic diagram explain the optical fiber communication system?Solution:

3. Video Broad Cost T V Tv Mini Cameras

4.In Data Sharing and communication Computers Cpu to peripherals Cpu to Cpu Lans Aircrafts Satellite ground station

5. Sensors Hydrophone Position Temp pressuring and current etc.

2) Derive an expression for numerical aperture of the fiber?Solution :

3) Explain the common optical fiber cable structure?

Solution :

4) With the Help of Snell’s law illustrate the phenomenon of Total internal reflections?

Or8) Explain the concept of total internal reflection using

snell’sLaw ?Solution :

5) What is numerical aperture? Deduce an expression for the same?Solution :

7. Compare the following fibers. Single – Mode step index Multi – Mode step index Graded index and give the typical dimensions also.

Solution : Pls attaché notes from Surya

11) Define Acceptance angle and Explain with diagram ?Solution :

13) Compare the optical communication with satellite communication?

Solution :Optical Communication Satellite Communication

1 Transmission Media is Optical Fiber cable

Transmission media is airline

2 Carrier Bandwidth is 105 GHZ

Carrier Bandwidth is 6 GHZ

3 Message signal is transmitted in the light with carrier

Message signal is transmitted in the electromagnetic with carrier

4 Low cost High Cost5 It required to boost the

signalNot required to boost the signal

6 Fast Communication Slow Communication7 Immunity to interference No immunity to interference8 High bandwidth Lower bandwidth