Fabrication of microphotonic waveguide components on silicon

Dissertation

Kimmo Solehmainen

Research output: ThesisDissertationCollection of Articles

Abstract

This thesis reports on the development of silicon-based microphotonic waveguide components, which are targeted in future optical telecommunication networks. The aim of the work was to develop the fabrication of silicon microphotonics using standard clean room processes which enable high volume production. The waveguide processing was done using photolithography and etching. The default waveguide structure was the rib-type, with the waveguide thickness varying from 2 to 10 µm. Most of the work was done with silicon-on-insulator (SOI) wafers, in which the waveguide core was formed of silicon. However, the erbium-doped waveguides were realised using aluminium oxide grown with atomic layer deposition. In the multi-step processing, the basic SOI rib waveguide structure was provided with additional trenches and steps, which offers more flexibility to the realisation of photonic integrated circuits. The experimental results included the low propagation loss of 0.13 and 0.35 dB/cm for SOI waveguides with 9 and 4 µm thicknesses, respectively. The first demonstration of adiabatic couplers in SOI resulted in optical loss of 0.5 dB/coupler and a broad spectral range. An arrayed waveguide grating showed a total loss of 5.5 dB. The work with SOI waveguides resulted also in a significant reduction of bending loss when using multi-step processing. In addition, a SOI waveguide mirror exhibited optical loss below 1 dB/90° and a vertical taper component between 10 and 4 µm thick waveguides had a loss of 0.7 dB. A converter between a rib and a strip SOI waveguides showed a negligible loss of 0.07 dB. In the Er-doped Al2O3 waveguides a strong Er-induced absorption was measured. This indicates potential for amplification applications, once a more uniform Er doping profile is achieved.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Aalto University
Supervisors/Advisors
  • Lipsanen, Harri, Supervisor, External person
Award date20 Apr 2007
Place of PublicationEspoo
Publisher
Print ISBNs978-951-38-6999-1
Electronic ISBNs978-951-38-7000-3
Publication statusPublished - 2007
MoE publication typeG5 Doctoral dissertation (article)

Fingerprint

waveguides
fabrication
silicon
insulators
couplers
clean rooms
theses
photolithography
tapering
atomic layer epitaxy
erbium
converters
integrated circuits
telecommunication
strip
flexibility
aluminum oxides
etching
wafers
gratings

Keywords

  • inductively coupled plasma etching
  • ICP
  • integrated optics
  • microphotonics
  • optical device fabrication
  • optical losses
  • silicon-on-insulator
  • waveguide
  • SOI
  • waveguide bends

Cite this

Solehmainen, K. (2007). Fabrication of microphotonic waveguide components on silicon: Dissertation. Espoo: VTT Technical Research Centre of Finland.
Solehmainen, Kimmo. / Fabrication of microphotonic waveguide components on silicon : Dissertation. Espoo : VTT Technical Research Centre of Finland, 2007. 102 p.
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abstract = "This thesis reports on the development of silicon-based microphotonic waveguide components, which are targeted in future optical telecommunication networks. The aim of the work was to develop the fabrication of silicon microphotonics using standard clean room processes which enable high volume production. The waveguide processing was done using photolithography and etching. The default waveguide structure was the rib-type, with the waveguide thickness varying from 2 to 10 µm. Most of the work was done with silicon-on-insulator (SOI) wafers, in which the waveguide core was formed of silicon. However, the erbium-doped waveguides were realised using aluminium oxide grown with atomic layer deposition. In the multi-step processing, the basic SOI rib waveguide structure was provided with additional trenches and steps, which offers more flexibility to the realisation of photonic integrated circuits. The experimental results included the low propagation loss of 0.13 and 0.35 dB/cm for SOI waveguides with 9 and 4 µm thicknesses, respectively. The first demonstration of adiabatic couplers in SOI resulted in optical loss of 0.5 dB/coupler and a broad spectral range. An arrayed waveguide grating showed a total loss of 5.5 dB. The work with SOI waveguides resulted also in a significant reduction of bending loss when using multi-step processing. In addition, a SOI waveguide mirror exhibited optical loss below 1 dB/90° and a vertical taper component between 10 and 4 µm thick waveguides had a loss of 0.7 dB. A converter between a rib and a strip SOI waveguides showed a negligible loss of 0.07 dB. In the Er-doped Al2O3 waveguides a strong Er-induced absorption was measured. This indicates potential for amplification applications, once a more uniform Er doping profile is achieved.",
keywords = "inductively coupled plasma etching, ICP, integrated optics, microphotonics, optical device fabrication, optical losses, silicon-on-insulator, waveguide, SOI, waveguide bends",
author = "Kimmo Solehmainen",
year = "2007",
language = "English",
isbn = "978-951-38-6999-1",
series = "VTT Publications",
publisher = "VTT Technical Research Centre of Finland",
number = "630",
address = "Finland",
school = "Aalto University",

}

Solehmainen, K 2007, 'Fabrication of microphotonic waveguide components on silicon: Dissertation', Doctor Degree, Aalto University, Espoo.

Fabrication of microphotonic waveguide components on silicon : Dissertation. / Solehmainen, Kimmo.

Espoo : VTT Technical Research Centre of Finland, 2007. 102 p.

Research output: ThesisDissertationCollection of Articles

TY - THES

T1 - Fabrication of microphotonic waveguide components on silicon

T2 - Dissertation

AU - Solehmainen, Kimmo

PY - 2007

Y1 - 2007

N2 - This thesis reports on the development of silicon-based microphotonic waveguide components, which are targeted in future optical telecommunication networks. The aim of the work was to develop the fabrication of silicon microphotonics using standard clean room processes which enable high volume production. The waveguide processing was done using photolithography and etching. The default waveguide structure was the rib-type, with the waveguide thickness varying from 2 to 10 µm. Most of the work was done with silicon-on-insulator (SOI) wafers, in which the waveguide core was formed of silicon. However, the erbium-doped waveguides were realised using aluminium oxide grown with atomic layer deposition. In the multi-step processing, the basic SOI rib waveguide structure was provided with additional trenches and steps, which offers more flexibility to the realisation of photonic integrated circuits. The experimental results included the low propagation loss of 0.13 and 0.35 dB/cm for SOI waveguides with 9 and 4 µm thicknesses, respectively. The first demonstration of adiabatic couplers in SOI resulted in optical loss of 0.5 dB/coupler and a broad spectral range. An arrayed waveguide grating showed a total loss of 5.5 dB. The work with SOI waveguides resulted also in a significant reduction of bending loss when using multi-step processing. In addition, a SOI waveguide mirror exhibited optical loss below 1 dB/90° and a vertical taper component between 10 and 4 µm thick waveguides had a loss of 0.7 dB. A converter between a rib and a strip SOI waveguides showed a negligible loss of 0.07 dB. In the Er-doped Al2O3 waveguides a strong Er-induced absorption was measured. This indicates potential for amplification applications, once a more uniform Er doping profile is achieved.

AB - This thesis reports on the development of silicon-based microphotonic waveguide components, which are targeted in future optical telecommunication networks. The aim of the work was to develop the fabrication of silicon microphotonics using standard clean room processes which enable high volume production. The waveguide processing was done using photolithography and etching. The default waveguide structure was the rib-type, with the waveguide thickness varying from 2 to 10 µm. Most of the work was done with silicon-on-insulator (SOI) wafers, in which the waveguide core was formed of silicon. However, the erbium-doped waveguides were realised using aluminium oxide grown with atomic layer deposition. In the multi-step processing, the basic SOI rib waveguide structure was provided with additional trenches and steps, which offers more flexibility to the realisation of photonic integrated circuits. The experimental results included the low propagation loss of 0.13 and 0.35 dB/cm for SOI waveguides with 9 and 4 µm thicknesses, respectively. The first demonstration of adiabatic couplers in SOI resulted in optical loss of 0.5 dB/coupler and a broad spectral range. An arrayed waveguide grating showed a total loss of 5.5 dB. The work with SOI waveguides resulted also in a significant reduction of bending loss when using multi-step processing. In addition, a SOI waveguide mirror exhibited optical loss below 1 dB/90° and a vertical taper component between 10 and 4 µm thick waveguides had a loss of 0.7 dB. A converter between a rib and a strip SOI waveguides showed a negligible loss of 0.07 dB. In the Er-doped Al2O3 waveguides a strong Er-induced absorption was measured. This indicates potential for amplification applications, once a more uniform Er doping profile is achieved.

KW - inductively coupled plasma etching

KW - ICP

KW - integrated optics

KW - microphotonics

KW - optical device fabrication

KW - optical losses

KW - silicon-on-insulator

KW - waveguide

KW - SOI

KW - waveguide bends

M3 - Dissertation

SN - 978-951-38-6999-1

T3 - VTT Publications

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Solehmainen K. Fabrication of microphotonic waveguide components on silicon: Dissertation. Espoo: VTT Technical Research Centre of Finland, 2007. 102 p.