cost291 presentation UoS

Slide1: 

Advanced Fibre Technologies&Applications group Dave Richardson Periklis Petropoulos Anoma McCoy Paulo Almeida Michaël Roelens Francesca Parmigiani Chun Tian Symeon Asimakis Federico Forte Optoelectronics Research Centre University of Southampton (UK)

Relevant Facilities: 

Relevant Facilities Fibre fabrication facilities – Holey and conventional fibres Fiber Bragg grating fabrication Telecommunication systems lab: Transmission, optical processing capabilities Pulse characterisation facilities: SHG-FROG, EAM-FROG, autocorrelation, optical sampling etc

Compound glass Holey Fibers: 

Compound glass Holey Fibers Target: Meter-long fiber-based nonlinear devices operating at low Power Levels Bismuth-oxide glasses combine a high nonlinearity with convenient physical properties for fiber fabrication In-house fabrication of extremely small-core Holey fibres Extrusion – alternative fabrication technique for soft glasses Die geometry determines geometry of the preform By adjusting the drawing parameters we can control the dimensions of the fibre core 1. extrusion 2. caning 3. drawing jacket tube structured preform Petropoulos\Asimakis

High Nonlinearity Holey Fibres: 

High Nonlinearity Holey Fibres Combination of a highly nonlinear glass with a very high NA fibre design Typical core diameter: 1.8 mm Fiber attenuation: (3.4 ± 0.5) dB/m Nonlinearity coefficient at 1550nm: (1100 ± 110) W-1km-1 Fibre has anomalous dispersion at 1550nm Nonlinearity measurement of the fibre SPM of 2ps solitons in 1.4m of the Bi-HF Petropoulos\Asimakis L=1.28m Nonlinear Phase Shift (rad) Input Power (mW)

Slide5: 

FBG encoders/decoders:basic principle Fiber Bragg Gratings (FBGs) fabrication technology has now matured significantly and can be applied in many applications in optical communication systems SSFBGs (SuperStructured Fiber Bragg Gratings ) are obtained by imposition of a varying amplitude and/or phase modulation along a refractive index profile of an otherwise uniform grating Highly controllable and linear method for manipulating phase and amplitude characteristics of short pulses Flexible FBG design and fabrication OCDMA systems based upon FBG coding/decoding devices have been demonstrated The superstructure function of the decoder grating is the spatially reversed profile of the encoder grating (to match the incoming code) Tian

Slide6: 

Scalability of SSFBGs

Pulse Shaping using SSFBGs: 

Pulse Shaping using SSFBGs Operate on pulses directly in the time domain using SSFBGs to effect pulse shaping Variety of short-pulse shaping functions is possible Rectangular pulses can be very useful for applications that require rectangular windows for nonlinear optical switching (retiming of data pulses) Parmigiani

Slide8: 

Retiming technique using SSFBG: Basic principle Switching with and without use of shaped rectangular pulses Each data pulse is expanded in the time domain, by shaping it into a relatively long rectangular pulse The maximum tolerable amount of timing jitter is defined by the duration of the rectangular pulse Pulses are switched with a synchronous optical clock signal in order to be re-timed and to go back to the initial pulsewidth Pulses reshaping Noisy Signal Clock Pulse Signal after all-optical switch Rectangular Pulses Signal after all-optical switch Noisy Signal Clock Pulse Parmigiani (a) (b)

TDM to WDM format conversion: 

TDM to WDM format conversion Almeida Concept relies on the switching of the data signal with a linearly chirped rectangular pulses Controlling high speed signals in time and in frequency at the same time

Slide10: 

HNLF NOLM HNLF NOLM EDFA EDFA PC PC 40 Gbit/s Receiver BPF 6 nm EDFA 220 m HNLF l0: 1549 nm BPF 3 nm EDFA PC PC BPF 1.4 nm 1 km HNLF l0:1539 nm EDFA Delay CW 1541.3 nm 40 Gbit/s RZ-OTDM Transmitter 10 GHz NRZ Chirped pulses 10 Gbit/s RZ Tunable Source 1 2 3 1 2 3 EDFA Delay drop add TFBG 40 Gbit/s input data 10 Gbit/s dropped channel 40 Gbit/s with added channel C1 C2 TDM-WDM converter WDM-TDM converter WADM 40 Gbit/s data with a dropped channel All-optical TDM add-drop multiplexer based on time to wavelength conversion Almeida

Multi-Wavelength EAM based Optical Sampling : 

Multi-Wavelength EAM based Optical Sampling FROG techique based on EAM (linear technique, low input power, very sensitive) One of the WDM channels is filtered out, to provide a clock signal to drive the EAM A spectral scan of the crosscorrelation with the EAM gate is acquired for each delay step t to create a WDM spectrogram Complete phase and intensity information about the pulses is known after numerical retrieval algorithm from the spectrogram The WDM stream of pulses is sampled simultaneously Roelens

Slide12: 

Multi-Wavelength EAM based Optical Sampling Roelens 8 WDM Channels simultaneously characterized without transmission and after transmission over 350m

Conclusions: 

Conclusions Strong interaction between fiber fabrication group and other research groups working on the applications of these fibers Our group has investigated a wide range of research topics: Holey Fibers SSFBGs encoding in OCDMA systems Regeneration technique using SSFBGs TDM-to-WDM conversion using linearly chirped rectangular pulses Monitoring amplitude and phase of the signal

Slide15: 

Extrusion Silica HF preforms typically made by stacking Extrusion – alternative technique for soft glasses Extrusion process: ->Glass billet and stainless still die are placed in stainless steel body ->Heat applied near to the glass softening temperature ->Applied pressure forces the glass through the die ->Die orifice geometry determines preform geometry

Fiber Nonlinearity:Basic Principles of the measurement: 

Fiber Nonlinearity: Basic Principles of the measurement A high-power, dual-frequency beat signal is applied Spectral sidebands arise due to Self-Phase Modulation in the fibre The intensity ratio between the signal and the first sideband depends on the nonlinear phase shift Linear relationship between the nonlinear phase shift and the launched power A.Boskovic, S.V. Chernikov et.al, Optics Letters, Vol.21, No.24

Tuneable FBG encoders: 

Tuneable FBG encoders Electrically reconfigurable phase encoder A uniform FBG is heated locally to introduce a phase shift in the structure The magnitude of the phase shift is controlled by the current flow in the wires Up to 16-chip 20 Gchip/s devices have been demonstrated Tian

Packet compression: 

Packet compression Almeida