Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Small-volume waveguide-section high Q microcavities in 2D photonic crystal slabs
KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
2004 (English)In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 12, no 17, 3988-3995 p.Article in journal (Refereed) Published
Abstract [en]

A series of microcavities in 2D hexagonal lattice photonic crystal slabs are studied in this paper. The microcavities are small sections of a photonic crystal waveguide. Finite difference time domain simulations show that these cavities preserve high Q modes with similar geometrical parameters and field profile. Effective modal volume is reduced gradually in this series of microcavity modes while maintaining high quality factor. Vertical Q value larger than 106 is obtained for one of these cavity modes with effective modal volume around 5.40 cubic half wavelengths [(lambda/2n(slab))(3)]. Another cavity mode provides even smaller modal volume around 2.30 cubic half wavelengths, with vertical Q value exceeding 10(5).

Place, publisher, year, edition, pages
2004. Vol. 12, no 17, 3988-3995 p.
Keyword [en]
Computer simulation, Crystal lattices, Finite difference method, Light reflection, Microstructure, Optical resonators, Optical waveguides, Time domain analysis, Finite difference time domain (FDTD) simulation, Microcavities, Microstructure devices, Photonic crystals (PC)
National Category
Atom and Molecular Physics and Optics
Identifiers
URN: urn:nbn:se:kth:diva-8017DOI: 10.1364/OPEX.12.003988ISI: 000223469000014Scopus ID: 2-s2.0-4644371173OAI: oai:DiVA.org:kth-8017DiVA: diva2:13226
Note
QC 20100922 QC 20110923Available from: 2008-02-22 Created: 2008-02-22 Last updated: 2017-12-14Bibliographically approved
In thesis
1. Silicon-based Photonic Devices: Design, Fabrication and Characterization
Open this publication in new window or tab >>Silicon-based Photonic Devices: Design, Fabrication and Characterization
2008 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

The field of Information and Communication Technologies is witnessing a development speed unprecedented in history. Moore’s law proves that the processor speed and memory size are roughly doubling each 18 months, which is expected to continue in the next decade. If photonics is going to play a substantial role in the ICT market, it will have to follow the same dynamics. There are mainly two groups of components that need to be integrated. The active components, including light sources, electro-optic modulators, and detectors, are mostly fabricated in III-V semiconductors. The passive components, such as waveguides, resonators, couplers and splitters, need no power supply and can be realized in silicon-related semiconductors. The prospects of silicon photonics are particularly promising, the fabrication is mostly compatible with standard CMOS technology and the on-chip optical interconnects are expected to increase the speed of microprocessors to the next generation.

This thesis starts with designs of various silicon-based devices using finite-difference time-domain simulations. Parallel computation is a powerful tool in the modeling of large-scale photonic circuits. High Q cavities and resonant channel drop filters are designed in photonic crystal platform. Different methods to couple light from a single mode fiber to silicon waveguides are studied by coupled-mode theory and verified using parallel simulations. The performance of waveguide grating coupler for vertical radiation is also studied.

The fabrication of silicon-based photonic devices involves material deposition, E-beam or optical lithography for pattern defining, and plasma/wet-chemistry etching for pattern transfer. For nanometer-scaled structures, E-beam lithography is the most critical process. Depending on the structures of the devices, both positive resist (ZEP520A) and negative resist (maN2405) are used. The proximity and stitch issues are addressed by careful dose correction and patches exposure. Some examples are given including photonic crystal surface mode filter, micro-ring resonators and gold grating couplers. In particular, high Q (2.6×105), deep notch (40 dB) and resonance-splitting phenomenon are demonstrated for silicon ring resonators.

It is challenging to couple light into photonic integrated circuits directly from a single-mode fiber. The butt-coupled light-injecting method usually causes large insertion loss due to small overlap of the mode profiles and large index mismatch. Practically it is not easy to cleave silicon sample with smooth facet where the waveguide exposes. By adding gold gratings to the waveguides, light can be injected and collected vertically from single-mode fiber. The coupling efficiency is much higher. There is no need to cleave the sample. The access waveguides are much shortened and the stitch problem in E-beam lithography is avoided.

In summary, this thesis introduces parallel simulations for the design of modern large-scale photonic devices, addresses various issues with Si-based fabrication, and analyses the data from the characterization. Several novel devices using silicon nanowire waveguides and 2D photonic crystal structures have been demonstrated for the first time.

Place, publisher, year, edition, pages
Stockholm: KTH, 2008. 58 p.
Series
Trita-ICT/MAP AVH, ISSN 1653-7610 ; 2008:5
Keyword
Photonic Devices, Silicon Photonics, Parallel Computation, Nanofabrication, Electron Beam Lithography, Optical Characterisation
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-4647 (URN)
Public defence
2008-03-07, N1, Electrum 3, Isafjordsgatan 28, Kista, 10:00
Opponent
Supervisors
Note
QC 20100923Available from: 2008-02-22 Created: 2008-02-22 Last updated: 2010-09-23Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Zhang, ZiyangQiu, Min
By organisation
Microelectronics and Information Technology, IMIT
In the same journal
Optics Express
Atom and Molecular Physics and Optics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 71 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf