Monolithically integrated tuneable slotted Fabry-Pérot laser, wavelength monitor and modulator

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dc.contributor.advisor Corbett, Brian en
dc.contributor.advisor Roycroft, Brendan en Ramaswamy, Prasanna 2019-10-03T08:43:29Z 2019 2019
dc.identifier.citation Ramaswamy, P. 2019. Monolithically integrated tuneable slotted Fabry-Pérot laser, wavelength monitor and modulator. PhD Thesis, University College Cork. en
dc.identifier.endpage 134 en
dc.description.abstract To aid the ever-increasing demand for data bandwidth, tuneable lasers will be a key requirement in transmitter modules of next-generation optical communication networks for data transmission in access networks. The lasers need to be wavelength-stabilised and cost is a critical factor since they will be widely used in consumer products. Currently used tuneable lasers in the downstream direction in access networks are too expensive to be also used widely in consumer products (upstream), and current designs for integrated wavelength monitors use passive waveguides made using spatially selective bandgap engineering techniques which are not cost-effective and make integration with a laser challenging. This thesis demonstrates a low-cost tuneable transmitter module using a slotted Fabry-Pérot laser, monolithically integrated with a modulator, wavelength monitor and a semiconductor optical amplifier (SOA). The laser is based on a 3-section slotted Fabry-Pérot design and has a discrete tuning range of about 20nm which covers half the C-band. The wavelength can be further fine-tuned by adjusting the temperature between 16-22⁰C with a sensitivity of approximately 0.1nm/⁰C. The modulator is an absorbing section with Ground-Signal-Ground (GSG) pads that is capable of delivering data rates of up to 10 Gb/s with a peak-to-peak driving voltage of 1V using Non-return-to-zero on-off-keying (NRZ-OOK) modulation. Error free transmission was achieved for distances up to 50km of single mode fibre. The module also incorporates an integrated semiconductor optical amplifier (SOA) which provides an optical gain control of up to 20dB with a drive current of 30mA. The wavelength monitor has a linear working range of approximately 25nm and can provide a sensitivity of 13-15GHz (~0.1nm). It employs the same epitaxial structure as the tuneable laser, thus requiring no regrowth, making monolithic integration possible. Along with the fact that the slots required for tuning of the laser are fabricated in the same step as the ridge waveguide, presenting no additional complexity during the fabrication process, makes the whole transmitter module low-cost and compatible for use in Optical Network Units (ONUs) in the consumers’ premises in a Fibre-to-the-Home (FTTH) scenario in access networks. The thesis also explores the challenges of integration such as electrical, optical and thermal crosstalk between the various active components within a single device and suggests design considerations that will help mitigate this crosstalk. For future work, the performance of the modulator section could be enhanced by the use of quantum well intermixing and also reducing its pad capacitance by introducing high-k dielectrics. After fabrication, the common substrate could be stripped off from underneath the entire device and the various components could be ‘printed’ separately on other substrates and optically connected via passive waveguides using novel transfer-printing technology, which could help reduce crosstalk further by eliminating substrate coupling. en
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher University College Cork en
dc.rights © 2019, Prasanna Ramaswamy. en
dc.rights.uri en
dc.subject Laser en
dc.subject Telecommunication en
dc.subject Tuneable en
dc.subject Crosstalk en
dc.subject Wavelength monitor en
dc.title Monolithically integrated tuneable slotted Fabry-Pérot laser, wavelength monitor and modulator en
dc.type Doctoral thesis en
dc.type.qualificationlevel Doctoral en
dc.type.qualificationname PhD en
dc.internal.availability Full text available en
dc.description.version Accepted Version
dc.contributor.funder Seventh Framework Programme en
dc.contributor.funder Science Foundation Ireland en
dc.description.status Not peer reviewed en Electrical and Electronic Engineering en Physics en
dc.check.reason This thesis contains data which has not yet been published en
dc.check.opt-out No en
dc.thesis.opt-out false
dc.check.entireThesis Entire Thesis Restricted
dc.check.embargoformat Apply the embargo to the e-thesis on CORA (If you have submitted an e-thesis and want to embargo it on CORA) en
dc.internal.conferring Autumn 2019 en
dc.internal.ricu Tyndall National Institute en
dc.relation.project info:eu-repo/grantAgreement/EC/FP7::SP1::ICT/318137/EU/The DIStributed Core for unlimited bandwidth supply for all Users and Services/DISCUS en

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© 2019, Prasanna Ramaswamy. Except where otherwise noted, this item's license is described as © 2019, Prasanna Ramaswamy.
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