Palushani, Evarist

Denne afhandling omhandler pulsformning og manipulering af optiske bølge- former til optisk signal behandling af ultrahurtige serielle data signaler, herunder frembringelsen optiske pulser af femtosekunders varighed, seriel til parallel konvertering, og koherent optisk tidslig multiplexing (OTDM) ved Terabaud symbolhastigheder. En stor del af afhandlingen fokuserer på brugen af rum-tid dualiteter til manipulering af pulsformer og Fourier transformation. Denne såkaldte rum-tid dualitet er baggrunden for optisk Fourier transformations (OFT) teknikken som bruges til at skifte mellem det tidslige og det spektrale domne. Ved at anvende OFT teknikken (fra frekvens til tid) og optisk tids differentiering baseret pa long-period gratings (LPG) lykkes det at frembringe ad-top pulser af pikosekunders varighed. Disse anvendes i forbindelse med OTDM demultiplexing til at dæmpe effekten af tidslig jitter samt til at opnå polarisationsuafhngighed. OFT teknikken (frekvens til tid) anvendes også til optisk synkronisering og re-timing. Denne afhandling præsenterer også en ny metode til optisk seriel til parallel konvertering baseret pa OFT teknikken (fra tid til frekvens). Denne metode er baseret pa firebølgeblanding (FWM) mellem disperserede OTDM pulser og lineært chirpede pumpe pulser, hvilket resulterer i en spektral komprimering af OTDM kanalerne der således kan konverteres direkte til et dense wavelength division multiplexing (DWDM) gitter. Metoden anvendes pa OTDM signaler med symbolrater op til 640 GBd som konverteres til DWDM gitre med kanalafstande fra 100 GHz og ned til 25 GHz, i overensstemmelse med ITU-T specifikationerne. Til sidst præsenteres nye resultater indenfor OTDM transmissionssystemer med digital kohrent detektion, hvor der opnås rekordhøje bit hastigheder for datasignaler på en bølgelængde. Her demonstreres 5.1 Tbit/s (640 GBd) transmission over 80 km fiber og 10.2 Tbit/s (1.28 TBd) transmission over 29 km dispersion managed fiber (DMF).The following thesis concerns pulse shaping and optical waveform manipulation for all-optical signal processing of ultra-high bit rate serial data signals, including generation of optical pulses in the femtosecond regime, serial-to-parallel conversion and terabaud coherent optical time division multiplexing (OTDM). Most of the thesis is focused on the utilization of spacetime dualities for temporal pulse shaping and Fourier transformation. The space-time duality led to the implementation of the optical Fourier transform (OFT) technique which was used as a crossing bridge between the temporal and spectral domain. By using the frequency-totime OFT technique or optical temporal differentiators based on long-period gratings (LPGs), it was possible to generate narrow at-top pulses in the picosecond regime, and use them for mitigation of timing jitter or polarization dependence effects in OTDM demultiplexing experiments. The frequency-to-time technique was deployed also for implementing an alloptical synchronizer and re-timer. By using the specular phenomenon, time-to-frequency OFT, it was possible to develop a novel scheme for serial-to-parallel conversion, implemented via four-wave mixing (FWM) between dispersed OTDM data and linearly chirped pump pulses. This resulted in spectral compression, enabling the OTDM tributaries to be converted directly onto a dense wavelength division multiplexing (DWDM) grid. The serial-to-parallel conversion was successfully demonstrated for up to 640-GBd OTDM signals, reaching DWDM grids ranging from 100 GHz down to 25 GHz spacing, compliant with ITU-T specications in terms of wavelength spacing and allocation. The final part of this thesis presents the latest results in OTDM transmission systems in combination with digital coherent detection, which enabled record-high serial data rates on a single-wavelength channel. The experimental results demonstrate 5.1- and 10.2-Tbit/s OTDM data signals achieved by 16-ary quadrature amplitude modulation (16-QAM), polarization multiplexing and symbol rates as high as 640 GBd and 1.28 TBd. These signal were transmitted with no penalty over 80- and 29-km dispersion-managed ber (DMF)

Online Research Database In Technology

Pulse shaping for all-optical signal processing of ultra-high bit rate serial data signals

http://orbit.dtu.dk/ws/files/10019552/epalu_phdthesis.pdf

Pulse shaping for all-optical signal processing of ultra-high bit rate serial data signals

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Online Research Database In Technology