Reach extension of passive optical networks using semiconductor optical amplifiers A E Kelly, C. Michie, I. Andonovic, J. McGeough, S Kariaganopoulos

Standard Passive Optical Networks GPON 1:32 Reach 10-20km

Extended Reach Passive Optical Networks Electronic regeneration cannot be used as it results in Preamble erosion due to burst mode locking time

Passive Optical Networks 1300nm backhaul transmitter 1310nm VOA1 SOA VOA2 20 nm filter receiver 1310nm VOA1 represents access loss – split plus some link loss VOA2 predominately trunk loss 1300 nm and 1.25/2.5 Gbit/s; dispersion neglected insertion loss α Significant ASE levels

Power Budget Simple linear model P in PIN or APD shot noise terms thermal noise receiver Noise Figure pin

Power Budget Simple linear model P in PIN or APD shot noise terms thermal noise receiver Noise Figure APD APD Multiplication and Noise Factor

SNR modified to account for ER of transmitter – at best 10 dB Power Budget

Baseline calculations APD Neo Photonics PTB3J T-SC/PC+ pin – OCP- TRXAG1M data modelled for commercial pin/APD

Inclusion of Amplifier Build upon a model of the SNR to include the noise terms associated with amplifier

Extinction Ratio further degraded due to ASE transmitter 1310nm VOA1 SOA VOA2 20 nm filter receiver 1310nm insertion loss α Significant ASE levels 0v

APD based Receiver Assumptions –-28 dBm sensitivity for BTB un amplified with 10 dB ER –M=10 –thermal noise estimated to give sensitivity of -28dBm for BER (value specified on data sheets) –P sat of SOA +13 dBm –NF 7 dB

Amplified APD Receiver Baseline 0.8nm filter 10 nm filter 20 nm filter ER not considered

Influence of Optical Filtering

Post Amplifier Losses Position amplifier to compensate for splitting and reach losses SOA P sat limited to +13 dBm Gain adjusted accordingly Splitter (Access) loss SOA Backhaul 20 nm filter OLT receiver 1310nm insertion loss α ONT

System Power Margins pre-amp marginbooster margin mid span margin benefit GPON

Margin Enhancement for Amplified GPON 128 split

64 split 128 split 32 Split 64 Split 512 Split Psat limited Gain limited NF limited GPON: 32 split Distance versus number of users for each case

Experiment VOA SOA VOAl Channel Drop OSA (filter) 1300 nm receiver 1300 tx

Experimental Validation

Constant BER curve with filter width

Experimental Margin Enhancement

Conclusions Number of users and backhaul distance can be considerably increased by using SOA based amplification Required SOA specification depends on placement within network A single SOA cannot meet these requirements Variable gain clamping schemes? Key Publications Russell P. Davey, Daniel B. Grossman, Michael Rasztovits-Wiech, David B. Payne, Derek Nesset, A. E. Kelly, Albert Rafel, Shamil Appathurai, and Sheng-Hui Yang Long-Reach Passive Optical Networks Journal of Lightwave Technology, Vol. 27, Issue 3, pp February 2009 (invited tutorial paper) High Performance Semiconductor Optical Amplifier Modules at 1300nmA.E.Kelly, C.Michie, I.Armstrong, I.Andonovic, C. Tombling, J.McGeough and B.C.Thomsen, Photon.Tech.Lett, Vol.18, No.24, pp , 2006 The Dynamic Gain Modulation Performance of Adjustable Gain-Clamped Semiconductor Optical Amplifiers (AGC-SOA) Liu, L. Michie, C. Kelly, A. E. Andonovic, I., Journal of Lightwave Technology, Volume: 29 Issue: 22 pp 3483 – 3489, 2011.