Optical communication based on wavelength reuse and modulation averaging

doctoral thesis

• Title (croatian): Optička komunikacija zasnovana na višestrukoj uporabi valne duljine i usrednjivanju modulacije
• Author: Marko Šprem
• Mentor: Dubravko Babić (mentor)
• Committee member: Dubravko Babić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Communication and Space Technologies); Zagreb
• Defense date and country: 2018, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing; Data Processing
• Universal decimal classification (UDC): 654 - Telecommunication and telecontrol

Abstract

Optical communication systems with wavelength reuse are systems in which a single wavelength is used for transmitting and receiving information over a single optical fiber. In such systems, the information encoded in the amplitude of an optical signal arriving at a terminal has to be erased before the signal is amplified and remodulated with new information. The doubling of bandwidth efficiency offered by wavelength reuse architectures is of special interest in wavelength division multiplex passive optical networks (WDM-PON) with wavelength-agnostic transceivers. Some of the desired features of such wavelength reuse systems include broadband operation, protocol transparency and passive operation, while one of the main challenges is preserving wavelength information through data erasure. This work describes the first demonstration of a wavelength reuse WDM-PON system in which the data erasure is accomplished by passive optical modulation averaging. To this end, several transceiver architectures were investigated: light was amplified using injection-locked Fabry-Pérot laser diodes (FP-LD) and semiconductor optical amplifiers, while remodulation was performed by either direct and external modulation. Best performance was demonstrated with RSOA architecture at a data rate of 1.25 Gbps and link length up to 30 km. The investigated architectures are inherently wavelength agnostic and can be employed in any intensity optical modulation. The modulation averaging structures were investigated for their depolarizing potential and use with coherent light.

Abstract (croatian)

Optički komunikacijski sustavi s višestrukom uporabom valne duljine su sustavi u kojima se ista valna duljina koristi za prijenos informacije u oba smjera kroz jedno optičko vlakno. U tim sustavima informacija zapisana u amplitudi optičkog signala koji ulazi u primopredajnik, mora biti izbrisana prije nego se signal pojača i re-modulira novom informacijom. Poseban interes mogućnosti dvostruko bolje frekvencijske iskoristivosti arhitektura s višestrukom uporabom valne duljine nalazi se u pasivnim optičkim mrežama s multipleksom po valnim duljinama (WDM-PON). Neka od željenih svojstava takvih sustava su širokopojasnost, transparentnost protokola i pasivni način rada, dok je glavni izazov očuvanje informacije o valnoj duljini nakon brisanja informacije. U ovom radu opisana je prva demonstracija WDM-PON s višestrukom uporabom valne duljine gdje je brisanje informacije izvedeno pasivnim optičkim usrednjavanjem modulacija. U tu svrhu, nekoliko arhitektura primopredajnika je istraženo: pojačanje svjetlosnog signala pomoću frekvencijsko zaključane Fabry-Pérot laserske diode (FP-LD) i svjetlovodnog optičkog pojačala, te re-modulacija putem direktne ili vanjske modulacije. Najbolje performanse demonstrirane su s RSOA arhitekturom s brzinom prijenosa od 1.25 Gbps i duljinom veze do 30 km. Istražene arhitekture su inherentno neovisne o valnoj duljini i mogu se implementirati s bilo kojom intenzitetnom optičkom modulacijom. Istražena su depolarizirajuća svojstva i mogućnost upotrebe koherentnog svjetla sa strukturama za usrednjavanje modulacija.

• Keywords: wavelength division multiplex; passive optical networks; Fabry-Pérot laser diode; injection-locking; temperature tuning; incoherent light; signal-to-noise ratio; modulation averaging; wavelength reuse
• Keywords (english): multipleksiranje po valnim duljinama; pasivne optičke mreže; Fabry-Pérot laserska dioda; frekvencijsko zaključavanje; temperaturno ugađanje; nekoherentno svjetlo; odnos signal-šum; usrednjavanje modulacija; višestruka uporaba valne duljine
• Language: english
• URN:NBN: urn:nbn:hr:168:987365
• Study programme: Title: Electrical Engineering and Computing; Study programme type: university; Study level: postgraduate; Academic / professional title: Doktor znanosti elektrotehnike i računarstva (Doktor znanosti elektrotehnike i računarstva)
• Type of resource: Text
• Extent: 107 str. ; 30 cm.
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-04-03 12:52:53