1.a) Describe the Historical background of optical fiber communications.

b) Discuss the Advantages and applications of fiber optical communications. [8+8]

2.a) Describe the propagation of light through an optical fiber and derive the equation for Acceptance angle.

b) A Step index fiber has a numerical aperture of 0.26, a core refractive index of 1.5 and a core diameter of 100 μm calculate:

i) Refractive Index of the Cladding

ii) The acceptance angle mi

iii) The minimum no of modes with a wavelength of 1 μm that the fiber can carry. [8+8]

3.a) Give an account on mode theory of circular wave guides.

b) Distinguish between step index and Graded Index Fibers. [8+8]

4.a) What are different losses in optical fiber? Write brief note on each?

b) Explain different types of dispersions in optical fiber. [8+8]

5.a) Explain the principle of Operation of LED and derive the equation for quantum efficiency of LED.

b) If a light from a LED having nominal efficiency 0.92% is allowed to fall on the circular detector kept at 1.2 inch distance from the LED, calculate the Irradiance at the detector for divergence angle 0.22 radians.

(HereFI and for LED is 80mA and 1.2V respectively). [16] FV

6.a) Explain the Noise mechanism in PIN photodiode.

b) Describe the principle of operation of APD and its parameters. [8+8]

7.a) Explain in detail about receiver performance.

b) Give an account on Rise-Time budget. [8+8]

8.a) Discuss the measurements of attenuation and dispersion.

b) Give an account on fiber splices and fiber connectors. [8+8]

* * * * * *

1.a) Give an account on mode theory of circular wave guides.

b) Distinguish between step index and Graded Index Fibers. [8+8]

2.a) What are different losses in optical fiber? Write brief note on each?

b) Explain different types of dispersions in optical fiber. [8+8]

3.a) Explain the principle of Operation of LED and derive the equation for quantum efficiency of LED.

b) If a light from a LED having nominal efficiency 0.92% is allowed to fall on the circular detector kept at 1.2 inch distance from the LED, calculate the Irradiance at the detector for divergence angle 0.22 radians.

(HereFI and for LED is 80mA and 1.2V respectively). [16] FV

4.a) Explain the Noise mechanism in PIN photodiode.

b) Describe the principle of operation of APD and its parameters. [8+8]

5.a) Explain in detail about receiver performance.

b) Give an account on Rise-Time budget. [8+8]

6.a) Discuss the measurements of attenuation and dispersion.

b) Give an account on fiber splices and fiber connectors. [8+8]

7.a) Describe the Historical background of optical fiber communications.

b) Discuss the Advantages and applications of fiber optical communications. [8+8]

8.a) Describe the propagation of light through an optical fiber and derive the equation for Acceptance angle.

b) A Step index fiber has a numerical aperture of 0.26, a core refractive index of 1.5 and a core diameter of 100 μm calculate:

i) Refractive Index of the Cladding

ii) The acceptance angle mi

iii) The minimum no of modes with a wavelength of 1 μm that the fiber can carry. [8+8]

* * * * * *

1.a) Explain the principle of Operation of LED and derive the equation for quantum efficiency of LED.

b) If a light from a LED having nominal efficiency 0.92% is allowed to fall on the circular detector kept at 1.2 inch distance from the LED, calculate the Irradiance at the detector for divergence angle 0.22 radians.

(HereFI and for LED is 80mA and 1.2V respectively). [16] FV

2.a) Explain the Noise mechanism in PIN photodiode.

b) Describe the principle of operation of APD and its parameters. [8+8]

3.a) Explain in detail about receiver performance.

b) Give an account on Rise-Time budget. [8+8]

4.a) Discuss the measurements of attenuation and dispersion.

b) Give an account on fiber splices and fiber connectors. [8+8]

5.a) Describe the Historical background of optical fiber communications.

b) Discuss the Advantages and applications of fiber optical communications. [8+8]

6.a) Describe the propagation of light through an optical fiber and derive the equation for Acceptance angle.

b) A Step index fiber has a numerical aperture of 0.26, a core refractive index of 1.5 and a core diameter of 100 μm calculate:

i) Refractive Index of the Cladding

ii) The acceptance angle mi

iii) The minimum no of modes with a wavelength of 1 μm that the fiber can carry. [8+8]

7.a) Give an account on mode theory of circular wave guides.

b) Distinguish between step index and Graded Index Fibers. [8+8]

8.a) What are different losses in optical fiber? Write brief note on each?

b) Explain different types of dispersions in optical fiber. [8+8]

* * * * * *

1.a) Explain in detail about receiver performance.

b) Give an account on Rise-Time budget. [8+8]

2.a) Discuss the measurements of attenuation and dispersion.

b) Give an account on fiber splices and fiber connectors. [8+8]

3.a) Describe the Historical background of optical fiber communications.

b) Discuss the Advantages and applications of fiber optical communications. [8+8]

4.a) Describe the propagation of light through an optical fiber and derive the equation for Acceptance angle.

b) A Step index fiber has a numerical aperture of 0.26, a core refractive index of 1.5 and a core diameter of 100 μm calculate:

i) Refractive Index of the Cladding

ii) The acceptance angle mi

iii) The minimum no of modes with a wavelength of 1 μm that the fiber can carry. [8+8]

5.a) Give an account on mode theory of circular wave guides.

b) Distinguish between step index and Graded Index Fibers. [8+8]

6.a) What are different losses in optical fiber? Write brief note on each?

b) Explain different types of dispersions in optical fiber. [8+8]

7.a) Explain the principle of Operation of LED and derive the equation for quantum efficiency of LED.

b) If a light from a LED having nominal efficiency 0.92% is allowed to fall on the circular detector kept at 1.2 inch distance from the LED, calculate the Irradiance at the detector for divergence angle 0.22 radians.

(HereFI and for LED is 80mA and 1.2V respectively). [16] FV

8.a) Explain the Noise mechanism in PIN photodiode.

b) Describe the principle of operation of APD and its parameters. [8+8]

* * * * * *

1. (a) Explain with relevant diagrams the basic principle of con nement of carriers

optical power in the active region of a double hetero junction LED.

(b) Discuss di erent modulation drive circuits for LED and explain their opera-

tions. [8+8]

2. (a) Estimate the maximum possible link length for operation at 60Mbps and BER

of 109 for the long haul single mode optical ber system operating at 850nm

and speci ed below.

Mean power launched from transmitter = -3dBm

Attenuation in optical ber cable = 2dB/Km

Loss in all splices = 0.3 dB/Km

Connector loss at the transmitter and receiver = 1.2dB/connector

Receiver sensitivity at 60Mbps for BER of 109 = -48dBm

Required safety margin = 8dB

(b) Is the above speci ed link attenuation limited for a 26 Km link length? If yes,

suggest a solution for eliminating the limitation. [10+6]

3. (a) The photo-elastic coe cient and the refractive index for silica are 0.286 and

1.46 respectively. Silica has an isothermal compressibility of 7 1011 m2

N1 and an estimated ctive temperature of 1400k. Determine the theoretical

attenuation in dB/ Km due to fundamental Rayleigh scattering in silica at

optical wavelengths of 0.85 and 1.55 m. Boltzmen constant is 1.381 1023

J K1.

(b) Distinguish between macro bending and micro bending losses in brief. [8+8]

4. Write brief notes on the following:

(a) Attenuation measurements for optical bers

(b) Wavelength division multiplexing for optical communication system. [8+8]

5. (a) Derive an expression for sensitivity of a PIN diode based digital ber optic

receiver including all the types of noise sources in the receiver.

(b) A silicon PIN diode with a responsivity of 0.5 A/W is operated at a binary

signaling rate of 35 Mbps and working at 850 nm wavelength. Determine the

minimum optical power required to be incident in order to maintain a BER

of 108. [8+8]

6. (a) Discuss the applications of optical ber in analog and digital applications.

(b) A graded index ber with a parabolic index pro le supports the propagation

of 742 guided modes. The ber has a numerical aperture in air of 0.3 and a

core diameter of 70 m. Determine the wavelength of the light propagating in

the ber. Also estimate the maximum diameter of the ber which gives single

mode operation at the same wavelength. [8+8]

7. (a) Discuss about the material dispersion in

uoride glasses.

(b) Explain about connector return losses. [8+8]

8. (a) Describe various mechanisms usable to increase power coupling from an LED

into a single mode ber. Discuss the intricacies involved.

(b) An LED with circular emitting region of radius 200 m and an axial radiance

of 60 W / cm2- Sr at 100mA drive current is coupled into a step index ber

of 50 m radius and 0.24 numerical aperture.

i. Compute the power coupled into this step index ber.

ii. Calculate the power coupled from the source speci ed about into a parabolic

index graded-index ber of same size as the step index ber with n1=1.485

and = 0.01. [6+5+5]

* * * * * *

1. (a) Estimate the maximum possible link length for operation at 60Mbps and BER

of 109 for the long haul single mode optical ber system operating at 850nm

and speci ed below.

Mean power launched from transmitter = -3dBm

Attenuation in optical ber cable = 2dB/Km

Loss in all splices = 0.3 dB/Km

Connector loss at the transmitter and receiver = 1.2dB/connector

Receiver sensitivity at 60Mbps for BER of 109 = -48dBm

Required safety margin = 8dB

(b) Is the above speci ed link attenuation limited for a 26 Km link length? If yes,

suggest a solution for eliminating the limitation. [10+6]

2. (a) Derive an expression for sensitivity of a PIN diode based digital ber optic

receiver including all the types of noise sources in the receiver.

(b) A silicon PIN diode with a responsivity of 0.5 A/W is operated at a binary

signaling rate of 35 Mbps and working at 850 nm wavelength. Determine the

minimum optical power required to be incident in order to maintain a BER

of 108. [8+8]

3. (a) The photo-elastic coe cient and the refractive index for silica are 0.286 and

1.46 respectively. Silica has an isothermal compressibility of 7 1011 m2

N1 and an estimated ctive temperature of 1400k. Determine the theoretical

attenuation in dB/ Km due to fundamental Rayleigh scattering in silica at

optical wavelengths of 0.85 and 1.55 m. Boltzmen constant is 1.381 1023

J K1.

(b) Distinguish between macro bending and micro bending losses in brief. [8+8]

4. (a) Explain with relevant diagrams the basic principle of con nement of carriers

optical power in the active region of a double hetero junction LED.

(b) Discuss di erent modulation drive circuits for LED and explain their opera-

tions. [8+8]

5. (a) Describe various mechanisms usable to increase power coupling from an LED

into a single mode ber. Discuss the intricacies involved.

(b) An LED with circular emitting region of radius 200 m and an axial radiance

of 60 W / cm2- Sr at 100mA drive current is coupled into a step index ber

of 50 m radius and 0.24 numerical aperture.

3

Code No: R05410403 R05 Set No. 4

i. Compute the power coupled into this step index ber.

ii. Calculate the power coupled from the source speci ed about into a parabolic

index graded-index ber of same size as the step index ber with n1=1.485

and = 0.01. [6+5+5]

6. (a) Discuss about the material dispersion in

uoride glasses.

(b) Explain about connector return losses. [8+8]

7. Write brief notes on the following:

(a) Attenuation measurements for optical bers

(b) Wavelength division multiplexing for optical communication system. [8+8]

8. (a) Discuss the applications of optical ber in analog and digital applications.

(b) A graded index ber with a parabolic index pro le supports the propagation

of 742 guided modes. The ber has a numerical aperture in air of 0.3 and a

core diameter of 70 m. Determine the wavelength of the light propagating in

the ber. Also estimate the maximum diameter of the ber which gives single

mode operation at the same wavelength. [8+8]

* * * * * *

1. Write brief notes on the following:

(a) Attenuation measurements for optical bers

(b) Wavelength division multiplexing for optical communication system. [8+8]

2. (a) Discuss about the material dispersion in

uoride glasses.

(b) Explain about connector return losses. [8+8]

3. (a) Estimate the maximum possible link length for operation at 60Mbps and BER

of 109 for the long haul single mode optical ber system operating at 850nm

and speci ed below.

Mean power launched from transmitter = -3dBm

Attenuation in optical ber cable = 2dB/Km

Loss in all splices = 0.3 dB/Km

Connector loss at the transmitter and receiver = 1.2dB/connector

Receiver sensitivity at 60Mbps for BER of 109 = -48dBm

Required safety margin = 8dB

(b) Is the above speci ed link attenuation limited for a 26 Km link length? If yes,

suggest a solution for eliminating the limitation. [10+6]

4. (a) Discuss the applications of optical ber in analog and digital applications.

(b) A graded index ber with a parabolic index pro le supports the propagation

of 742 guided modes. The ber has a numerical aperture in air of 0.3 and a

core diameter of 70 m. Determine the wavelength of the light propagating in

the ber. Also estimate the maximum diameter of the ber which gives single

mode operation at the same wavelength. [8+8]

5. (a) The photo-elastic coe cient and the refractive index for silica are 0.286 and

1.46 respectively. Silica has an isothermal compressibility of 7 1011 m2

N1 and an estimated ctive temperature of 1400k. Determine the theoretical

attenuation in dB/ Km due to fundamental Rayleigh scattering in silica at

optical wavelengths of 0.85 and 1.55 m. Boltzmen constant is 1.381 1023

J K1.

(b) Distinguish between macro bending and micro bending losses in brief. [8+8]

6. (a) Describe various mechanisms usable to increase power coupling from an LED

into a single mode ber. Discuss the intricacies involved.

(b) An LED with circular emitting region of radius 200 m and an axial radiance

of 60 W / cm2- Sr at 100mA drive current is coupled into a step index ber

of 50 m radius and 0.24 numerical aperture.

i. Compute the power coupled into this step index ber.

ii. Calculate the power coupled from the source speci ed about into a parabolic

index graded-index ber of same size as the step index ber with n1=1.485

and = 0.01. [6+5+5]

7. (a) Derive an expression for sensitivity of a PIN diode based digital ber optic

receiver including all the types of noise sources in the receiver.

(b) A silicon PIN diode with a responsivity of 0.5 A/W is operated at a binary

signaling rate of 35 Mbps and working at 850 nm wavelength. Determine the

minimum optical power required to be incident in order to maintain a BER

of 108. [8+8]

8. (a) Explain with relevant diagrams the basic principle of con nement of carriers

optical power in the active region of a double hetero junction LED.

(b) Discuss di erent modulation drive circuits for LED and explain their opera-

tions. [8+8]

* * * * * *

1. (a) Describe various mechanisms usable to increase power coupling from an LED

into a single mode ber. Discuss the intricacies involved.

(b) An LED with circular emitting region of radius 200 m and an axial radiance

of 60 W / cm2- Sr at 100mA drive current is coupled into a step index ber

of 50 m radius and 0.24 numerical aperture.

i. Compute the power coupled into this step index ber.

ii. Calculate the power coupled from the source speci ed about into a parabolic

index graded-index ber of same size as the step index ber with n1=1.485

and = 0.01. [6+5+5]

2. (a) Explain with relevant diagrams the basic principle of con nement of carriers

optical power in the active region of a double hetero junction LED.

(b) Discuss di erent modulation drive circuits for LED and explain their opera-

tions. [8+8]

3. (a) Derive an expression for sensitivity of a PIN diode based digital ber optic

receiver including all the types of noise sources in the receiver.

(b) A silicon PIN diode with a responsivity of 0.5 A/W is operated at a binary

signaling rate of 35 Mbps and working at 850 nm wavelength. Determine the

minimum optical power required to be incident in order to maintain a BER

of 108. [8+8]

4. (a) The photo-elastic coe cient and the refractive index for silica are 0.286 and

1.46 respectively. Silica has an isothermal compressibility of 7 1011 m2

N1 and an estimated ctive temperature of 1400k. Determine the theoretical

attenuation in dB/ Km due to fundamental Rayleigh scattering in silica at

optical wavelengths of 0.85 and 1.55 m. Boltzmen constant is 1.381 1023

J K1.

(b) Distinguish between macro bending and micro bending losses in brief. [8+8]

5. (a) Discuss the applications of optical ber in analog and digital applications.

(b) A graded index ber with a parabolic index pro le supports the propagation

of 742 guided modes. The ber has a numerical aperture in air of 0.3 and a

core diameter of 70 m. Determine the wavelength of the light propagating in

the ber. Also estimate the maximum diameter of the ber which gives single

mode operation at the same wavelength. [8+8]

6. (a) Discuss about the material dispersion in

uoride glasses.

(b) Explain about connector return losses. [8+8]

7. Write brief notes on the following:

(a) Attenuation measurements for optical bers

(b) Wavelength division multiplexing for optical communication system. [8+8]

8. (a) Estimate the maximum possible link length for operation at 60Mbps and BER

of 109 for the long haul single mode optical ber system operating at 850nm

and speci ed below.

Mean power launched from transmitter = -3dBm

Attenuation in optical ber cable = 2dB/Km

Loss in all splices = 0.3 dB/Km

Connector loss at the transmitter and receiver = 1.2dB/connector

Receiver sensitivity at 60Mbps for BER of 109 = -48dBm

Required safety margin = 8dB

(b) Is the above speci ed link attenuation limited for a 26 Km link length? If yes,

suggest a solution for eliminating the limitation. [10+6]

* * * * * ** * * * * *

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