Photonic Systems Group

Transcription

1 Photonic Systems Group Projects offered by: Cleitus Antony and Prof. Paul Townsend Project 1. Study of transmission impairments in high speed optical communication system. Project 2. Time-resolved measurement of modulation induced chirp.

2 30 members, 10 nationalities, 13 PhD students PhD Students Photonic Systems Group Shiyu Zhou Xing Ouyang Amandeep Kaur Niamh Kavanagh Brian Murray Marco Dalla Santa Stefano Facchin Teddy Lesmana Daniel Carey Denis Kelly + Meysam Khanghah, Natalia Estrada, Yukui Yu Post Doctoral Researchers Cleitus Antony Hsinta Wu Hongyu Zhang Anil Jain Neil Gonzalez Stefano Porto Lu Zhang Alan Naughton Nicola Brandonisio Senior Post Doctoral Researcher, Research Fellows, Senior Staff Khosrov Sadeghipour Peter Ossieur Jian Zhao Fatima Gunning Giuseppe Talli Bob Manning Paul Townsend 2

3 There is enough optical fibre in the world to encircle the globe more than 50,000 times The exploding internet 85% of all new software are available as cloud services* More than 20 Billion smart devices will be connected by 2020** Approximately 50% of internet traffic will be video by 2016*** * IBM Cloud Fact sheet 2014 **Strategy Analytics ***Cisco visual networking index 3

4 Develop new network concepts Long reach passive optical network and flat optical core Traditional telecommunication network Metro node consolidation 6000 nodes <200 nodes Integrated all optical Metro & Access: long reach passive optical network 4

5 Multi-mode capacity enhancement with photonic bandgap fibre High capacity coherent WDM transmitter optical communication at 2μm Introduce disruptive technology Traditional telecommunication network World s first Linear burst mode receiver for passive optical networks Cost efficient advanced modulation formats in passive optical networks Quantum Dot based Raman amplified passive optical network. 5

6 Validation via field trials Cork To Clonakilty Clonakilty 1000km of optical fibre available for field trials High capacity metro & core networks: 2 Tbit/s coherent WDM field trial New modulation schemes for high capacity metro : 480km, 40Gb/s Improved optical fast OFDM scheme using intensity-modulation and full-field detection Next generation fibre to the home (FTTH): 135km, 8192 split, 10Gb/s DWDM long reach PON field trial. DWDM: Dense Wavelength Division Multiplexing OFDM: Orthogonal Frequency Division Multiplexing 6

7 Core Competence: Information transport using light Modify a Signal Modulate φ CLADDING = 125μm Optical Fibre Detect the Modifications Demodulate φ CORE = 8μm Example of constellations of various modulation formats NRZ : Non return to zero DQPSK : Differential Quadrature Phase Shift Keying PM QPSK : Polarisation Multiplexed Quadrature Phase Shift Keying a) Time Division Multiplexing b) Wavelength Division Multiplexing c) Orthogonal Frequency Division Multiplexing 7

8 Transmission Experiment Pulse Amplitude Modulation PAM 2 PAM 2 1 V th 0 PAM 4 PAM V th 3 V th 2 V th 1 8

9 Example Eye Diagram, Histograms -15dBm Rx input Power -20dBm Rx input Power Best Sampling Point 10GBaud 9

10 Signal Signal Chromatic Dispersion Chromatic dispersion (CD) is due to the fact that the refractive index of silica depends on its optical frequency (different components travel at different speeds) Pulse spreading caused by CD eventually results in inter-symbol interference (ISI) leading to errors in the recovery of transmitted symbols Signal IN Dispersive fibre Signal OUT Probability Probability , ,

11 ISI Analysis: Effect of Fibre Dispersion 10Gbaud Fibre Length: 0. 1km Fibre Length: 50km Fibre Length: 80km BER = BER = BER =

12 Fibre Chromatic Dispersion Measurement Frequency swept sinusoidal signal and detection

13 Time-resolved Frequency chirp

14 Photonic Systems Lab Pattern Generator (up to 25Gb/s) 50 km Fibre Optical Spectrum Analyser 160GS/s, 50GHz Real time Scope High Power Laser

15 Signal Analysis tool

16 Signal Analysis tool