Progress Toward Fast Reconfigurable Optical Cross-connect Prasanna A. Gamage, Huug e Waardt COBRA Research Institute, Technical niversity of Eindhoven. In Co-operation with SurfNet.
Outline Overview Existing Reconfigurable Cross-connect - AS3 otivation AS3 AS4 Fast Reconfigurable Optical Cross-connect esign Optical Cross-connect design EFA Gain ynamics in reconfigurable Transmission Systems Summary
Existing System AS3 Transponder ultiplexer e-multiplexer V Free niversity of Amsterdam AS3 ASON The Netherlands Institute for Radio omy Erbium oped Fiber Amplifier t Technical niversity of elft L niversity of Leiden Issue va niversity of Amsterdam Logical topology switching time is around 15 minutes Can become a major hindrance for applications sensitive to latency
otivation V AS4-FP ASON L va t AS3 L va Objective of the project Fast Reconfigurable Optical Cross-connect switch with logical topology switching time on the order of milliseconds.
otivation V AS4-FP ASON Focus L va nderstand the impact of switching on EFA performance. Power excursion due to EFA gain dynamics. Logical Topologies V V V V V Case 1 Case 2 Case 3 Case 4 Case 5 L va L va L va L va L va
Fast Reconfigurable Optical Cross-Connect esign Basic Building Blocks Wavelength Selective Switch (WSS) technologies Fast Reconfigurable Optical Cross-connect esign Analysis of EFA Gain ynamic in Reconfigurable Transmission Systems Simulation results
Basic Building Blocks Arrayed waveguide gratings (AWG) Wavelength channel ux/emux Optical power splitters Can be used for broadcasting Tunable optical filters Wavelength Selective Switch (WSS) Individual wavelengths on a common input fiber can be selectively switched to any of multiple output fibers. Broadcasting is not possible Reciprocal device λ 1 λ 2 λ 3 λ 4 λ 5 λ 6 λ 7 λ 8 λ 9 λ 10 Wavelength Selective Switch Common input 1 2 3 4 5 6 7 8 9 λ 1 λ 7 Ø λ 3 λ 2 λ 5 Ø Ø λ 4 λ 9 λ 8 λ 6 λ 10 Electrical controls
Schematic esign Fast Reconfigurable Optical Cross-Connect L L va va ASON ASON Broadcast-Select Architecture Scaling Large port count V V Enough amplification Counter the losses Splitter WSS
Simulation Reconfigurable Transmission System for EFA Gain ynamic Analysis Optical power transient behavior due to switching Optical power excursion in remaining channels due to channel drop Optical power excursion in channels due to channel add Sudden optical power surge could impair the receiver performance.
T T T AS4-FP R R R L L T T T va EFA transient response does not propagate va R R R T R T R T T R T 84 km 97 km R T 97 km 84 km R R T ASON EFA transient response does not propagate ASON R T T R T R T R R T T R T 45 km 45 km R R T R T R V V
R1 R2 R3 R1 R2 R3 R4 R1 R2 R3 AS4-FP R1 R2 R3 R4 T1 T2 T3 T4 T T T1 T2 T3 T1 T2 T3 45 km 84 km 97 km T1 T2 T3 T4 V ASON L va ASON L va V
T1 T2 T3 AS4-FP R1 R2 R3 V L L Case 1 T1 T2 T3 va va R1 R2 R3 L V va T1 R1 Case 2 T2 T3 T4 R2 R3 R4 L va T1 T2 T3 T4 T ASON ASON R1 R2 R3 R4 Switching Channels compete for gain omentary increase in channel optical power due to channel drop and add T V Case 1 2 V
Simulation model WSS
Fast Reconfigurable Optical Cross-Connect Switch
Simulation setup - Reconfigurable Transmission System
Simulation Results Subset of logical topology transitions representing all the possible power level changes V V V V Case 1 Case 2 Case 1 Case 3 L va L va L va L va V V V V Case 1 Case 4 Case 1 Case 5 L va L va L va L va
Simulation Results 5 0 Optical Power Evolution Channel at L Node Transient Optical Power Evolution - Channel at L Node (Close p) 2 1.5 Optical Power (dbm) -5-10 -15-20 Optical Power (dbm) 1 0.5 0 140 µs 1.6 db -25-0.5 Case 1 to 2 Case 1 to 2-30 -1 0 0.5 1 1.5 1 1.1 1.2 1.3 Time (ms) Time (ms) 1.4 1.5 Power excursion L Node Power excursion of added channel is 1.6 db
Simulation Results Optical Power Evolution Channel at ASON Node (Close p) 1 5 Optical Power Evolution Channel at ASON Node 4 Optical Power (dbm) 0.5 0 135 µs 0.8 db Optical Power (dbm) 3 2 1 4.73 db 0 Case 1 to 2 Case 1 to 2-0.5-1 1 1.1 1.2 1.3 1.4 1.5 0 0.5 Time (ms) Time (ms) 1 1.5 Power excursion ASON Node Power excursion of added channel is 0.8 db Power excursion of the remaining (express) channel 4.73 db Power excursion for all the transitions In the remaining channel < 4.8 db In the added channels < 1.8 db
Summary Briefly discussed the AS4 reconfigurable cross-connect optical switch. Simulated the reconfigurable transmission system to analyze the impact of EFA gain dynamics on system performance. omentary power increase in the remaining channel due to channel drop < 4.8 db for all the cases omentary power increase in channels due to channel add < 1.8 db for all the cases Next phase will be the implementation of our design. Acknowledgement: SurfNet
Insertion Losses Switch = 17 db ( 1x8 coupler 9 db, WSS insertion loss = 6.5 db, Connector loss = 0.5 db + PL = 1 db) 8x8 AWG = 7.5 db (Polarization dependent loss + Loss niformity + Insertion loss = 0.5 + 1 + 6) Connector loss = 0.25 db 10 Gbps Transponder (OIF Specification) Transmitter Spectral Range = 1530 nm to 1565 nm Extinction ratio = 10 db Output Power = -2.5 dbm PIN Receiver Sensitivity = - 16.5 dbm @ BER = 10-15 (Post FEC) Rx overload = + 7 dbm @ 1550nm Loss ispersion SF G.652 0.26 db/km 17 ps/nm-km True Wave RS TW-RS 0.23 db/km 4 ps/nm-km AWG CH# λ (nm) 1 1558.17 2 1558.58 3 1558.98 4 1559.39 5 1559.79 6 1560.20 7 1560.61 8 1561.01