1. BY: SUPERVISION TEAM:

2. Proposed core optical router Source / target node

3. All-optical router

4. Symetric Mach-Zehnder Interferometer(SMZI)

6. To design a bi-directional SMZ and implement it in the router to reduce components, time and cost.

7. To optimize the performance of the SOA to be adapted for bi-directional operation. To overcome the slow time recovery of the SOA gain. To propose a bi-directional model for the SOA. To design a bi-directional model for the SMZ and implement it in the proposed router.

8. Injection current (I) L Input facet of active region Input signals Output signals Output facet H w

10. segment1segment2…………..…………….segment5 t=0 g t=l/v g t=L/v g input signal output signal NiNi N(1) N(5)

11. Normalised gain response of the SOA with no input signal.

12. Normalised gain response of the SOA due to the injection of a short input pulse. Injection of the input pulse

13. Normalised gain response of the SOA due to the injection of a continuous input signal. Injection of the continuous wave Saturation gain

14. Carrier density along the SOA length after applying a continuous wave. Injection of the continuous wave

16. Condition:  The signal should not be affected by the SOA nonlinear effect (i.e: SOA gain depletion should not reach saturation value). Note:  The reference is the saturation value for a 1mW continuous input signal.

17. The output gain corresponding to the input power at different bias currents. Reference saturation gain: at I=150mA 66 at I=200mA 96 at I=250mA 127

19. Condition: – The signal should be affected by the nonlinearity of the SOA and achieve a 180 o phase shift for the deconstructive interference. (i.e: SOA gain depletion of a control pulse (CP) should reach the gain saturation value). Note: – A control pulse (CP) is required to be launched to the SOA, then the input signal should be injected in order to achieve the 180 o phase shift.

20. The saturation control pulse (CP) for the corresponding input power at different bias currents.

22. SOA gain dependence on the bias current.

23. Normalised gain response of the SOA due to the injection of a short input pulse. Recovery time

24. Normalised gain response of the SOA due to partial increase of the bias current.

25. segment1segment2…………..…………….segment5 t=0 g t=l/v g t=L/v g Propagating input signal Propagating output signal Partial increase of bias current

26. SOA gain recovery due to the additional of different bias currents. Recovery time=37ps Improvement of: 86% for 95% recovery 90% for 99% recovery 84% for 100% recovery

27. SOA bit rate due to the additional bias current. SOA bit rate=27.027 Gbps Improvement of: 7.5 times at 95% recovery

28. Time needed to apply additional bias current. Time needed : 35ps for 90mA 154ps for 10mA

31. segment1segment2…………..…………….segment5 t=0 g t=l/v g t=L/v g Propagating input signal Propagating output signal Co-propagating input signal Co-propagating output signal

33. Uni-directional SMZ

34. Bi-directional SMZ

36. Practical work on the SMZ. The replacement of active components in the router by passive components (FBGs) such as demultiplexing, add/drop devices, filtering, and switching. Solving the contention resolution problem using a novel multiplexing solution.

37. The SOA is modelled using a segmentation method. The effect of input parameters on the gain and carrier density response of an SOA is presented. Optimum performance conditions are investigated in which the SOA can be used as a standalone amplifier and in a SMZ switch. The dependence on of the SOA on the bias current is presented.

38. Results show an acceleration in the gain recovery time due to partially increasing the bias current applied to the SOA. SOA gain recovery time and bit rate corresponding to the additional bias current is investigated.