This set of Optical Communications Problems focuses on “Dispersion Management and Soliton Systems”.

1. Calculate second order dispersion coefficient for path length L_{2} 20km and L_{1} 160km. Dispersion coefficient for L_{2} is 17.

a) -2.125ps/nm km

b) -3.25ps/nm km

c) -3.69ps/nm km

d) -1.28ps/nm km

View Answer

Explanation: The second order dispersion coefficient for path length is given by-

β

_{21}=-β

_{22}L

_{2}/L

_{1}. Here, β

_{22}= Dispersion coefficient forL

_{2}, L

_{2}and L

_{1}are path lengths.

2. Calculate the path length L_{2} if L_{1}is 160, dispersion coefficient of L_{2} is 17, dispersion coefficient of L_{1}is -2.25 ps/nmkm.

a) 40 km

b) 20 km

c) 30 km

d) 10 km

View Answer

Explanation: The path length L

_{2}is given by-

L

_{2}=β

_{21}L

_{1}/-β

_{22}. Here, β

_{22}= Dispersion coefficient forL

_{2}, β

_{21}= Dispersion coefficient for L

_{1}, L

_{2}and L

_{1}are path lengths.

3. Calculate path length L_{1} if L_{2}is 20, dispersion coefficient of L_{2} is 17, dispersion coefficient of L_{1} is -2.25 ps/nmkm.

a) 180 km

b) 30 km

c) 160 km

d) 44 km

View Answer

Explanation: The path length L1is given by-

L

_{1}=β

_{21}L

_{2}/-β

_{22}. Here, β

_{22}= Dispersion coefficient forL

_{2}, β

_{21}= Dispersion coefficient for L

_{1}, L

_{2}and L

_{1}are path lengths.

4. Calculate second order dispersion coefficient for path length L_{1}20km and L_{1}160km. Dispersion coefficient for L_{1} is -2.125*10^{-12}s/nmkm.

a) 20

b) 19

c) 18

d) 17

View Answer

Explanation: The second order dispersion coefficient for path length is given by-

β

_{22}=-β

_{21}L

_{2}/L

_{1}. Here, β21= Dispersion coefficient forL1, L

_{2}and L1are path lengths.

5. Calculate dispersion slope for second path fiber if L_{1} is 150, L_{2} is 10 and s_{1} is 0.075.

a) 1.125

b) 2.125

c) 3.125

d) 1.9

View Answer

Explanation: Dispersion slope for second path fiber is s

_{2}=-s

_{1}(L

_{1}/L

_{2}). Here s1 and s2 are dispersion slopes for L

_{1}, L

_{2}. L

_{2}and L

_{1}are path lengths.

6. Calculate dispersion slope for first path fiber if L_{1}is 160, L_{2}is 20 and s_{2} is 0.6ps/nm km.

a) 0.1

b) 0.432

c) 0.236

d) 0.075

View Answer

Explanation: Dispersion slope for first path fiber is s

_{1}=-s

_{2}(L

_{1}/L

_{2}). Here s1 and s2 are dispersion slopes forL

_{1}, L

_{2}. L

_{2}And L

_{1}are path lengths.

7. Calculate L_{2} if dispersion slope for first path fiber is 0.075 and L_{1} is 160 km and s_{2}is -0.6ps/nm km.

a) 20 km

b) 30 km

c) 40 km

d) 50 km

View Answer

Explanation: L

_{2}is determined by –

L2= (-s

_{1}/s

_{2})* L

_{1}. Here s

_{1}and s

_{2}are dispersion slopes for L

_{1}, L

_{2}. L

_{2}and L

_{1}are path lengths.

8. Calculate L_{1} if dispersion slope for first path fiber is 0.075 and L_{2} is 20 km and s_{2} is -0.6ps/nm km.

a) 170 km

b) 160 km

c) 180 km

d) 175 km

View Answer

Explanation: L

_{1}is determined by –

L

_{2}= (-s

_{1}/s

_{2})* L

_{2}. Here s

_{1}and s

_{2}are dispersion slopes forL

_{1}, L

_{2}. L

_{2}and L

_{1}are path lengths.

9. Calculate separation of soliton pulses over a bit period length if R_{2} pulse width is 6 ps for bit period of 70 ps.

a) 5.9

b) 5.7

c) 5.8

d) 5.4

View Answer

Explanation: The separation of soliton pulses over a bit period length is calculated by –

q

_{0}= T

_{0}/2ς. Here ς=pulse width and T

_{0}=bit period.

10. Calculate RZ pulse width if bit period is 60ps and separation of soliton pulses is 5.4.

a) 5.5ps

b) 8.1ps

c) 4.3ps

d) 2.3ps

View Answer

Explanation: RZ pulse width can be calculated by –

ς=T

_{0}/q

_{0}. Here ς=pulse width and T

_{0}=bit period.

11. Calculate bit period if RZ pulse width is 50ps and separation of soliton pulses is 5.6.

a) 570ps

b) 540ps

c) 430ps

d) 560ps

View Answer

Explanation: Bit period can be calculated by –

T

_{0}= 2T

_{2}q

_{0}. Here T

_{2}=pulse width and T

_{0}=bit period.

12. Calculate value of dimensionless parameter if bit period is 45ps and RZ pulse width is 4 ps.

a) 5.625

b) 5.0

c) 4

d) 6.543

View Answer

Explanation: Dimensionless parameter is given by –

q

_{0}= T

_{0}/2ς. Here ς=pulse width and T

_{0}=bit period.

**Sanfoundry Global Education & Learning Series – Optical Communications.**

To practice all areas of Optical Communications Problems, __here is complete set of 1000+ Multiple Choice Questions and Answers__.