Optical communications Simulation 3

Simulation Point to point link – single wavelength Point to point link – multiple wavelengths

Dispersion compensation Bit rate: 40Gb/s, bit length: 8 bit User define bit sequence: 00010001 Dispersion: 20 ps/nm/km

Question 1 Change the fiber length to 5 km. Observe the result without the FBG. Connect the FBG and FBG dispersion to -100ps/nm Explain the input/output result

Question 2 Change the fiber length to 10 km. Explain the output result. Compensate the dispersion of 10 km fiber by changing the FBG dispersion value.

Loss compensation Source: continuous wave (CW) laser, 0 dBm at 1550 nm. Bit rate: 10Gb/s, length: 128 bit

Question 3 Plot: Min. log of BER vs fiber length from 40 km to 100 km. Explain the result.

Loss compensation Add an EDFA between a 50km fiber and another fiber.

Question 4 Plot Min. log of BER vs the second fiber length (20km to 50 km). Compare with the case when no amplifier is used.

Multi-wavelength link Power budget – multi-wavelength

Question 5 Plot: Min. log of BER vs fiber length from 40 km to 100 km. Compare to the single wavelength case. (no amplifier)

Question 6 In the multi-wavelength system, add an EDFA between a 50km fiber and another fiber. Plot Min. log of BER vs the second fiber length. Determine the second fiber length where the BER is 10-9. Compare with the single wavelength case.

Question 7 Set the second fiber length at the newly found value, use a dispersion compensator to further decrease BER. Where should the compensator be connected? Find the optimum value of dispersion compensation, and BER at that value.