Microphotonic silicon waveguide components

Aalto, Timo

Microphotonic silicon waveguide components

dc.contributor	Aalto-yliopisto	fi
dc.contributor	Aalto University	en
dc.contributor.author	Aalto, Timo
dc.contributor.department	Department of Electrical and Communications Engineering	en
dc.contributor.department	Sähkö- ja tietoliikennetekniikan osasto	fi
dc.date.accessioned	2012-02-13T12:56:38Z
dc.date.available	2012-02-13T12:56:38Z
dc.date.issued	2004-12-10
dc.description.abstract	This thesis describes the design, simulation, fabrication and characterisation of microphotonic silicon waveguide components on silicon-on-insulator (SOI) substrates. The focus is on approximately 10 μm thick and single-moded (SM) silicon rib waveguides. In particular, simulation results are given for straight and bent Si waveguides, directional couplers (DCs), thermo-optically (TO) modulated Mach-Zehnder interferometers (MZI), and waveguide gratings. A new analytical SM condition for Si rib waveguides is proposed and the development of a new grating simulation algorithm is reported. The theoretical part of the work also involves inventions relating to multi-step patterning of Si waveguides, modulation of interferometric devices, and measurement of polarisation axes from waveguides and polarisation maintaining (PM) fibers. Clean room processing of waveguide chips is briefly described. Main process steps are photolithography, electron-beam lithography, thermal oxidation, oxide deposition, oxide dry etching and Si dry etching. Post-processing of the chip is also reported, including dicing, polishing, anti-reflection (AR) coating, fiber pigtailing and wire bonding. The development of fabrication processes for multi-step patterning, waveguide gratings and photonic crystal waveguides is reported, although the optical characterisation of devices based on these three processes is not included in the thesis. Experimental results are given for Si rib waveguides with different thicknesses (H) and widths (W). The minimum fiber coupling loss with H = 9 μm was 1.3 dB/facet without an AR coating. The AR coating reduced the coupling loss by 0.7-0.8 dB/facet. Minimum propagation loss for a 114 cm long waveguide spiral with H = 9 μm and W = 7 μm was 0.13 dB/cm. With H = 9 μm, the birefringence varied from 0.00063 to <0.0001 depending on the cladding material, and the maximum polarisation extinction ratio for straight waveguides and directional couplers was >15 dB. Furthermore, fast modulation with 15 dB extinction ratio (ER) is reported for TO MZI switches by using both traditional (10 kHz) and novel (167 kHz) modulation methods. Rise and fall times for single switching operations were pushed below 750 ns with 9 dB ER. The setups and methods used in measurements are described in detail, including a novel method for measuring the polarisation axes of waveguides and PM fibers.	en
dc.description.version	reviewed	en
dc.format.extent	78, [73]
dc.format.mimetype	application/pdf
dc.identifier.isbn	951-38-6423-5
dc.identifier.issn	1455-0849
dc.identifier.uri	https://aaltodoc.aalto.fi/handle/123456789/2452
dc.identifier.urn	urn:nbn:fi:tkk-004150
dc.language.iso	en	en
dc.publisher	VTT Technical Research Centre of Finland	en
dc.publisher	VTT	fi
dc.relation.haspart	T. Aalto, M. Harjanne, M. Kapulainen, P. Heimala, and M. Leppihalme, Development of silicon-on-insulator waveguide technology, Photonics West 2004, San Jose, USA, 26-29 January 2004. Proceedings of SPIE, Vol. 5355, pp. 81-95, 2004. [article1.pdf] © 2004 SPIE. By permission.
dc.relation.haspart	M. Harjanne, T. Aalto, Design of tight bends in silicon-on-insulator ridge waveguides, Physica Scripta, Vol. T114, pp. 209-212, 2004.
dc.relation.haspart	T. Aalto, P. Heimala, and P. Katila, Integrated optical switch based on SOI-technology, Physica Scripta, Vol. T79, pp. 123-126, 1999.
dc.relation.haspart	T. Aalto, M. Kapulainen, S. Yliniemi, P. Heimala, and M. Leppihalme, Fast thermo-optical switch based on SOI waveguides, Photonics West 2003, San Jose, USA, 27-29 January, 2003. Proceedings of SPIE, Vol. 4987, pp. 149-159, 2003. [article4.pdf] © 2003 SPIE. By permission.
dc.relation.haspart	M. Harjanne, M. Kapulainen, T. Aalto, and P. Heimala, Sub-μs switching time in silicon-on-insulator Mach–Zehnder thermooptic switch, Photonics Technology Letters, Vol. 16, No. 9, pp. 2039-2041, 2004. [article5.pdf] © 2004 IEEE. By permission.
dc.relation.haspart	J. Tervo, M. Kuittinen, P. Vahimaa, J. Turunen, T. Aalto, P. Heimala, and M. Leppihalme, Efficient Bragg waveguide-grating analysis by quasi-rigorous approach based on Redheffer's star product, Optics Communications, Vol. 198, pp. 265-272, 2001. [article6.pdf] © 2001 Elsevier Science. By permission.
dc.relation.haspart	P. Heimala, T. Aalto, S. Yliniemi, J. Simonen, M. Kuittinen, J. Turunen, and M. Leppihalme, Fabrication of Bragg grating structures in silicon, Physica Scripta, Vol. T101, pp. 92-95, 2002.
dc.relation.haspart	T. Aalto, M. Harjanne, and M. Kapulainen, Method for the rotational alignment of polarization-maintaining optical fibers and waveguides, Optical Engineering, Vol. 42, Issue 10, pp. 2861-2867, 2003. [article8.pdf] © 2003 Society of Photo-Optical Instrumentation Engineers. By permission.
dc.relation.ispartofseries	VTT publications	en
dc.relation.ispartofseries	553	en
dc.subject.keyword	silicon microphotonics	en
dc.subject.keyword	integrated optics	en
dc.subject.keyword	silicon-on-insulator waveguides	en
dc.subject.keyword	SOI waveguides	en
dc.subject.keyword	waveguide bends	en
dc.subject.keyword	thermo-optical switching	en
dc.subject.keyword	multi-step patterning	en
dc.subject.keyword	polarisation maintaining fibers	en
dc.subject.keyword	polarisation extinction ratio	en
dc.subject.other	Electrical engineering	en
dc.title	Microphotonic silicon waveguide components	en
dc.type	G5 Artikkeliväitöskirja	fi
dc.type.dcmitype	text	en
dc.type.ontasot	Väitöskirja (artikkeli)	fi
dc.type.ontasot	Doctoral dissertation (article-based)	en
local.aalto.digiauth	ask
local.aalto.digifolder	Aalto_66759