Fabrication and characterization of polymer optical waveguides with integrated micromirrors for three-dimensional board-level optical interconnects

M. Immonen, Mikko Karppinen, J. Kivilahti

Research output: Contribution to journalArticleScientificpeer-review

57 Citations (Scopus)

Abstract

This paper describes the fabrication and characterization of optical/electrical printed circuit boards (O/E-PCB) with embedded multimodal step index (MM-SI) waveguides and integrated out-of-plane micromirrors (IMMs) for three-dimensional (3-D) optical interconnects. Optical circuitry is built up on PCBs using UV lithography; 45º input/output (I/O) couplers are fabricated by inclined exposure. Commercial polymers are used as optical core and cladding materials. Critical mirror properties of angle, surface quality, reflectivity, and coupling efficiency are characterized experimentally and theoretically. Optical and scanning electron microscopy, white light interferometry, and fiber scanning method are used in the investigations. Sloping profiles measured as a function of the incident light showed the attainment of mirror angles of α = 36º-45º with ±2º consistency. Near-field optical imaging with a white light source showed that out-of-plane beam turning was achieved. Topography investigations revealed a rectilinear negative tapering shape regardless of the incoming beam angle or type of substrate. However, higher substrate reflectancy was observed to lower the mirror angle. The average propagation loss measured for 10-cm-long waveguides at λ = 850 nm by the cut-back method was 0.60 dB/cm; the excess loss calculated for the mirror coupling was 1.8-2.3 dB. The results showed that the IMMs can be incorporated in O/E-PCBs to couple light in and out of planar waveguides. Furthermore, the presented results indicate that optical waveguides with integrated micromirrors for optical 3-D wiring can be produced compatible with volume manufacturing techniques.
Original languageEnglish
Pages (from-to)304 - 311
Number of pages8
JournalIEEE Transactions on Electronics Packaging Manufacturing
Volume28
Issue number4
DOIs
Publication statusPublished - 2005
MoE publication typeA1 Journal article-refereed

Fingerprint

Optical interconnects
Optical waveguides
Polymers
Mirrors
Fabrication
Polychlorinated Biphenyls
Polychlorinated biphenyls
Waveguides
Planar waveguides
Electric wiring
Substrates
Interferometry
Printed circuit boards
Topography
Lithography
Surface properties
Light sources
Scanning
Imaging techniques
Scanning electron microscopy

Keywords

  • board-level optics
  • optics
  • micromirrors
  • optical printed circuit boards
  • printed circuit boards
  • printed circuits
  • o-PCBs
  • polymer optical waveguides
  • three-dimensional interconnects

Cite this

@article{6daf9d8873f342bfb3e26de3cdc31821,
title = "Fabrication and characterization of polymer optical waveguides with integrated micromirrors for three-dimensional board-level optical interconnects",
abstract = "This paper describes the fabrication and characterization of optical/electrical printed circuit boards (O/E-PCB) with embedded multimodal step index (MM-SI) waveguides and integrated out-of-plane micromirrors (IMMs) for three-dimensional (3-D) optical interconnects. Optical circuitry is built up on PCBs using UV lithography; 45º input/output (I/O) couplers are fabricated by inclined exposure. Commercial polymers are used as optical core and cladding materials. Critical mirror properties of angle, surface quality, reflectivity, and coupling efficiency are characterized experimentally and theoretically. Optical and scanning electron microscopy, white light interferometry, and fiber scanning method are used in the investigations. Sloping profiles measured as a function of the incident light showed the attainment of mirror angles of α = 36º-45º with ±2º consistency. Near-field optical imaging with a white light source showed that out-of-plane beam turning was achieved. Topography investigations revealed a rectilinear negative tapering shape regardless of the incoming beam angle or type of substrate. However, higher substrate reflectancy was observed to lower the mirror angle. The average propagation loss measured for 10-cm-long waveguides at λ = 850 nm by the cut-back method was 0.60 dB/cm; the excess loss calculated for the mirror coupling was 1.8-2.3 dB. The results showed that the IMMs can be incorporated in O/E-PCBs to couple light in and out of planar waveguides. Furthermore, the presented results indicate that optical waveguides with integrated micromirrors for optical 3-D wiring can be produced compatible with volume manufacturing techniques.",
keywords = "board-level optics, optics, micromirrors, optical printed circuit boards, printed circuit boards, printed circuits, o-PCBs, polymer optical waveguides, three-dimensional interconnects",
author = "M. Immonen and Mikko Karppinen and J. Kivilahti",
year = "2005",
doi = "10.1109/TEPM.2005.856538",
language = "English",
volume = "28",
pages = "304 -- 311",
journal = "IEEE Transactions on Components, Packaging and Manufacturing Technology",
issn = "2156-3950",
publisher = "IEEE Institute of Electrical and Electronic Engineers",
number = "4",

}

Fabrication and characterization of polymer optical waveguides with integrated micromirrors for three-dimensional board-level optical interconnects. / Immonen, M.; Karppinen, Mikko; Kivilahti, J.

In: IEEE Transactions on Electronics Packaging Manufacturing, Vol. 28, No. 4, 2005, p. 304 - 311.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Fabrication and characterization of polymer optical waveguides with integrated micromirrors for three-dimensional board-level optical interconnects

AU - Immonen, M.

AU - Karppinen, Mikko

AU - Kivilahti, J.

PY - 2005

Y1 - 2005

N2 - This paper describes the fabrication and characterization of optical/electrical printed circuit boards (O/E-PCB) with embedded multimodal step index (MM-SI) waveguides and integrated out-of-plane micromirrors (IMMs) for three-dimensional (3-D) optical interconnects. Optical circuitry is built up on PCBs using UV lithography; 45º input/output (I/O) couplers are fabricated by inclined exposure. Commercial polymers are used as optical core and cladding materials. Critical mirror properties of angle, surface quality, reflectivity, and coupling efficiency are characterized experimentally and theoretically. Optical and scanning electron microscopy, white light interferometry, and fiber scanning method are used in the investigations. Sloping profiles measured as a function of the incident light showed the attainment of mirror angles of α = 36º-45º with ±2º consistency. Near-field optical imaging with a white light source showed that out-of-plane beam turning was achieved. Topography investigations revealed a rectilinear negative tapering shape regardless of the incoming beam angle or type of substrate. However, higher substrate reflectancy was observed to lower the mirror angle. The average propagation loss measured for 10-cm-long waveguides at λ = 850 nm by the cut-back method was 0.60 dB/cm; the excess loss calculated for the mirror coupling was 1.8-2.3 dB. The results showed that the IMMs can be incorporated in O/E-PCBs to couple light in and out of planar waveguides. Furthermore, the presented results indicate that optical waveguides with integrated micromirrors for optical 3-D wiring can be produced compatible with volume manufacturing techniques.

AB - This paper describes the fabrication and characterization of optical/electrical printed circuit boards (O/E-PCB) with embedded multimodal step index (MM-SI) waveguides and integrated out-of-plane micromirrors (IMMs) for three-dimensional (3-D) optical interconnects. Optical circuitry is built up on PCBs using UV lithography; 45º input/output (I/O) couplers are fabricated by inclined exposure. Commercial polymers are used as optical core and cladding materials. Critical mirror properties of angle, surface quality, reflectivity, and coupling efficiency are characterized experimentally and theoretically. Optical and scanning electron microscopy, white light interferometry, and fiber scanning method are used in the investigations. Sloping profiles measured as a function of the incident light showed the attainment of mirror angles of α = 36º-45º with ±2º consistency. Near-field optical imaging with a white light source showed that out-of-plane beam turning was achieved. Topography investigations revealed a rectilinear negative tapering shape regardless of the incoming beam angle or type of substrate. However, higher substrate reflectancy was observed to lower the mirror angle. The average propagation loss measured for 10-cm-long waveguides at λ = 850 nm by the cut-back method was 0.60 dB/cm; the excess loss calculated for the mirror coupling was 1.8-2.3 dB. The results showed that the IMMs can be incorporated in O/E-PCBs to couple light in and out of planar waveguides. Furthermore, the presented results indicate that optical waveguides with integrated micromirrors for optical 3-D wiring can be produced compatible with volume manufacturing techniques.

KW - board-level optics

KW - optics

KW - micromirrors

KW - optical printed circuit boards

KW - printed circuit boards

KW - printed circuits

KW - o-PCBs

KW - polymer optical waveguides

KW - three-dimensional interconnects

U2 - 10.1109/TEPM.2005.856538

DO - 10.1109/TEPM.2005.856538

M3 - Article

VL - 28

SP - 304

EP - 311

JO - IEEE Transactions on Components, Packaging and Manufacturing Technology

JF - IEEE Transactions on Components, Packaging and Manufacturing Technology

SN - 2156-3950

IS - 4

ER -