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PGNET 20071 M. F. Chiang M. F. Chiang, Z. Ghassemlooy, Wai Pang Ng, and H. Le Minh Optical Communication Research Group Northumbria University, United.

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Presentation on theme: "PGNET 20071 M. F. Chiang M. F. Chiang, Z. Ghassemlooy, Wai Pang Ng, and H. Le Minh Optical Communication Research Group Northumbria University, United."— Presentation transcript:

1 PGNET M. F. Chiang M. F. Chiang, Z. Ghassemlooy, Wai Pang Ng, and H. Le Minh Optical Communication Research Group Northumbria University, United Kingdom Simulation of an All-Optical 1  2 SMZ Switch with a High Contrast Ratio

2 PGNET M. F. Chiang Contents Introduction Symmetric Mach-Zehnder (SMZ) Optical inverter based on SMZ All-Optical 1  2 SMZ Switch with a High Contrast Ratio Simulation Results Conclusions

3 PGNET M. F. Chiang Introduction- Research Aim  There is a growing demand for all optical switches and router at very high speed, to avoid the bottleneck imposed by the electronic switches.  All-optical switches, such as SMZs are the key components adopted for switching and routing due to their ultrafast switching time (pico- to sub- picoseconds). However, SMZs have low inter-output CR (< 10 dB).  It is essential to have a high inter-output CR switch for lower value of output crosstalk (CXT).

4 PGNET M. F. Chiang Ref: UNI TOAD Ref: (Princeton) Ref: (Japan) Introduction All-Optical Switches

5 PGNET M. F. Chiang Semiconductor Optical Amplifier (SOA) Input signals (light) Carrier density & SOA gain (XGM) SOA refractive index & Induced phase (XPM) Input signals P N Injection current SOA

6 PGNET M. F. Chiang SMZ (Symmetric Mach-Zehnder) Advantages: 1.narrow and square switching window 2.compact size 3.thermal stability and low power operation Drawback: 1. Low inter-output CR (< 10 dB) due to the problem of maintaining the same phase shift. Undesired signal

7 PGNET M. F. Chiang S’(t+π/2) S’(t) S’’(t) S’’’(t) S’’’(t+π/2) P out,1 (t)=S’’’(t)+S’’’(t+π/2+π/2) P out,2 (t)=S’’’(t+π/2)+S’’’(t+π/2) P in (t)=S(t) Signals emerge from output2 S’(t+π/2) S’(t) S’’(t) S’’(t+π/2) S’’’(t+ π) S’’’(t+π/2) P out,1 (t)=S’’’(t + π)+S’’’(t+π/2+π/2) P out,2 (t)=S’’’(t+π/2 + π)+S’’’(t+π/2) P in (t)=S(t) Signals emerge form output1 CP1 π Case 1: Without CP (SMZ is balanced) Case 2: With CP1 only (SMZ unbalanced)Case 3: With both CP1&CP2 (SMZ is balanced again) CP2 π P out,2 (t)=S’’’(t+π/2 + π)+S’’’(t+π/2 + π) P out,1 (t)=S’’’(t + π)+S’’’(t+π/2+π/2 + π) Signals emerge from output2 again S’’’(t+π/2+ π ) Symmetric Mach-Zehnder (SMZ) Case 1: Without CP (SMZ is balanced) Case 2: With CP1 only (SMZ unbalanced) PC2 Output2 Output1 Coupler4 Coupler3 Coupler2 Coupler1 SOA2 SOA1 PBS PC1 PBS S’’(t+π/2) PC2 Output2 Output1 Coupler4 Coupler3 Coupler2 Coupler1 SOA2 SOA1 PBS PC1 PBS PC 3-dB coupler PBS

8 PGNET M. F. Chiang All-Optical 1  2 SMZ Switch with a High Contrast Ratio CEM: clock extraction module low inter-output CR (< 10 dB) Improved CR (> 32 dB)

9 PGNET M. F. Chiang All-optical inverter based on SMZ AA bar SOA Input (CLK) CP 1 (CLK) CP 2 (A) Output (A bar)

10 PGNET M. F. Chiang Simulation Results-Simulation Parameter Simulation Tool: Virtual Photonic Inc. (VPI) TABLE I SOA SIMULATION PARAMETER TABLE II SIGNAL AND CONTROL PULSES DEFAULT PARAMETERS

11 PGNET M. F. Chiang Simulation Results-Time Waveforms Output waveforms observed at the proposed 1  2 switch Input packets Control pulse Output1 Output2

12 PGNET M. F. Chiang Simulation Results-Time Waveforms Output CR ratio observed at the proposed 1  2 switch CR (< 10 dB) The improved CR (> 30 dB)

13 PGNET M. F. Chiang Simulation Results- The contrast ratio (CR) against the input packet power

14 PGNET M. F. Chiang Conclusion  In this paper, the advantages and drawbacks of SMZs were introduced.  The principle of the proposed all-optical 1  2 SMZ switch with a high contrast ratio was explained.  It was shown that a high Inter-output CR ( > 32 dB) was achieved over a wide range of input packet power (12 dB).  The proposed 1  2 switch offered an improvement in the inter-output CR of ~ 25 dB in comparison with a single SMZ switch. The proposed switch could potentially be adopted for high-speed signal processing and packet routing in all-optical networks.

15 PGNET M. F. Chiang Special Thanks Special Thanks for Prof. Fary Ghassemlooy Dr. Wai Pang Ng Mr. Hoa Le Minh All colleagues in NCRL & Your Attention

16 PGNET M. F. Chiang Thank You ! Question, please ?


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