Comparison of different types of MMI-resonators fabricated on a micron-scale SOI platform

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

1x1 optical resonators have been designed based on multi-mode interference (MMI) splitters of different splitting ratios (85:25 and 73:27) and different types of back-reflectors as feedback mechanism. They are basically 2x2 MMIs of uneven splitting ratios with one of the ports from both sides ending in a reflector. The chosen reflectors include metal-dielectric mirrors, waveguide loops and MMI reflectors. The remaining two ports play the role of input and thru port respectively. The resonant wavelengths are reflected back in the input port, hence acting also as output port in reflection. The devices have been fabricated on SOI wafers with a 3 µm-thick silicon layer. In all cases, the quality factors of the resonances of a given resonator have been found to significantly change form peak to peak. This can be attributed to wavelength dependent losses in the feedback mechanisms, that is wavelength dependent reflectivity of the back-reflectors. Through a suitable transfer matrix model, we have found that best performing devices correspond to reflectivity as high as 92% for the metal/dielectric mirrors and 88% for the MMI reflectors, corresponding to a resonator finesse of 13.1 and 9.9 respectively. The free spectral ranges of the resonators vary from about 3 nm to about 1 nm, depending on the cavity length, which is constrained by the lengths of both the MMIs and the reflectors. When suitably combined with gain elements, the proposed resonators are promising candidates as fabrication tolerant wavelength selective reflectors for external cavity lasers.
Original languageEnglish
Title of host publicationSilicon Photonics X
PublisherInternational Society for Optics and Photonics SPIE
DOIs
Publication statusPublished - 27 Feb 2015
MoE publication typeA4 Article in a conference publication
EventSilicon Photonics X - San Francisco, United States
Duration: 9 Feb 201512 Feb 2015

Publication series

NameProceedings of SPIE
PublisherSPIE
Volume9367
ISSN (Print)0277-786X

Conference

ConferenceSilicon Photonics X
Abbreviated titleSPIE OPTO
CountryUnited States
CitySan Francisco
Period9/02/1512/02/15

Fingerprint

SOI (semiconductors)
reflectors
platforms
resonators
interference
wavelengths
mirrors
reflectance
optical resonators
laser cavities
metals
Q factors
wafers
waveguides
cavities
fabrication
output
silicon

Keywords

  • integrated optics
  • multimode interference splitters
  • optical resonators
  • photonic integrated circuits
  • silicon photonics

Cite this

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title = "Comparison of different types of MMI-resonators fabricated on a micron-scale SOI platform",
abstract = "1x1 optical resonators have been designed based on multi-mode interference (MMI) splitters of different splitting ratios (85:25 and 73:27) and different types of back-reflectors as feedback mechanism. They are basically 2x2 MMIs of uneven splitting ratios with one of the ports from both sides ending in a reflector. The chosen reflectors include metal-dielectric mirrors, waveguide loops and MMI reflectors. The remaining two ports play the role of input and thru port respectively. The resonant wavelengths are reflected back in the input port, hence acting also as output port in reflection. The devices have been fabricated on SOI wafers with a 3 µm-thick silicon layer. In all cases, the quality factors of the resonances of a given resonator have been found to significantly change form peak to peak. This can be attributed to wavelength dependent losses in the feedback mechanisms, that is wavelength dependent reflectivity of the back-reflectors. Through a suitable transfer matrix model, we have found that best performing devices correspond to reflectivity as high as 92{\%} for the metal/dielectric mirrors and 88{\%} for the MMI reflectors, corresponding to a resonator finesse of 13.1 and 9.9 respectively. The free spectral ranges of the resonators vary from about 3 nm to about 1 nm, depending on the cavity length, which is constrained by the lengths of both the MMIs and the reflectors. When suitably combined with gain elements, the proposed resonators are promising candidates as fabrication tolerant wavelength selective reflectors for external cavity lasers.",
keywords = "integrated optics, multimode interference splitters, optical resonators, photonic integrated circuits, silicon photonics",
author = "Matteo Cherchi and Mikko Harjanne and Sami Ylinen and Markku Kapulainen and Tapani Vehmas and Timo Aalto",
year = "2015",
month = "2",
day = "27",
doi = "10.1117/12.2079606",
language = "English",
series = "Proceedings of SPIE",
publisher = "International Society for Optics and Photonics SPIE",
booktitle = "Silicon Photonics X",
address = "United States",

}

Cherchi, M, Harjanne, M, Ylinen, S, Kapulainen, M, Vehmas, T & Aalto, T 2015, Comparison of different types of MMI-resonators fabricated on a micron-scale SOI platform. in Silicon Photonics X., 936713, International Society for Optics and Photonics SPIE, Proceedings of SPIE, vol. 9367, Silicon Photonics X, San Francisco, United States, 9/02/15. https://doi.org/10.1117/12.2079606

Comparison of different types of MMI-resonators fabricated on a micron-scale SOI platform. / Cherchi, Matteo; Harjanne, Mikko; Ylinen, Sami; Kapulainen, Markku; Vehmas, Tapani; Aalto, Timo.

Silicon Photonics X. International Society for Optics and Photonics SPIE, 2015. 936713 (Proceedings of SPIE, Vol. 9367).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

TY - GEN

T1 - Comparison of different types of MMI-resonators fabricated on a micron-scale SOI platform

AU - Cherchi, Matteo

AU - Harjanne, Mikko

AU - Ylinen, Sami

AU - Kapulainen, Markku

AU - Vehmas, Tapani

AU - Aalto, Timo

PY - 2015/2/27

Y1 - 2015/2/27

N2 - 1x1 optical resonators have been designed based on multi-mode interference (MMI) splitters of different splitting ratios (85:25 and 73:27) and different types of back-reflectors as feedback mechanism. They are basically 2x2 MMIs of uneven splitting ratios with one of the ports from both sides ending in a reflector. The chosen reflectors include metal-dielectric mirrors, waveguide loops and MMI reflectors. The remaining two ports play the role of input and thru port respectively. The resonant wavelengths are reflected back in the input port, hence acting also as output port in reflection. The devices have been fabricated on SOI wafers with a 3 µm-thick silicon layer. In all cases, the quality factors of the resonances of a given resonator have been found to significantly change form peak to peak. This can be attributed to wavelength dependent losses in the feedback mechanisms, that is wavelength dependent reflectivity of the back-reflectors. Through a suitable transfer matrix model, we have found that best performing devices correspond to reflectivity as high as 92% for the metal/dielectric mirrors and 88% for the MMI reflectors, corresponding to a resonator finesse of 13.1 and 9.9 respectively. The free spectral ranges of the resonators vary from about 3 nm to about 1 nm, depending on the cavity length, which is constrained by the lengths of both the MMIs and the reflectors. When suitably combined with gain elements, the proposed resonators are promising candidates as fabrication tolerant wavelength selective reflectors for external cavity lasers.

AB - 1x1 optical resonators have been designed based on multi-mode interference (MMI) splitters of different splitting ratios (85:25 and 73:27) and different types of back-reflectors as feedback mechanism. They are basically 2x2 MMIs of uneven splitting ratios with one of the ports from both sides ending in a reflector. The chosen reflectors include metal-dielectric mirrors, waveguide loops and MMI reflectors. The remaining two ports play the role of input and thru port respectively. The resonant wavelengths are reflected back in the input port, hence acting also as output port in reflection. The devices have been fabricated on SOI wafers with a 3 µm-thick silicon layer. In all cases, the quality factors of the resonances of a given resonator have been found to significantly change form peak to peak. This can be attributed to wavelength dependent losses in the feedback mechanisms, that is wavelength dependent reflectivity of the back-reflectors. Through a suitable transfer matrix model, we have found that best performing devices correspond to reflectivity as high as 92% for the metal/dielectric mirrors and 88% for the MMI reflectors, corresponding to a resonator finesse of 13.1 and 9.9 respectively. The free spectral ranges of the resonators vary from about 3 nm to about 1 nm, depending on the cavity length, which is constrained by the lengths of both the MMIs and the reflectors. When suitably combined with gain elements, the proposed resonators are promising candidates as fabrication tolerant wavelength selective reflectors for external cavity lasers.

KW - integrated optics

KW - multimode interference splitters

KW - optical resonators

KW - photonic integrated circuits

KW - silicon photonics

U2 - 10.1117/12.2079606

DO - 10.1117/12.2079606

M3 - Conference article in proceedings

T3 - Proceedings of SPIE

BT - Silicon Photonics X

PB - International Society for Optics and Photonics SPIE

ER -

Cherchi M, Harjanne M, Ylinen S, Kapulainen M, Vehmas T, Aalto T. Comparison of different types of MMI-resonators fabricated on a micron-scale SOI platform. In Silicon Photonics X. International Society for Optics and Photonics SPIE. 2015. 936713. (Proceedings of SPIE, Vol. 9367). https://doi.org/10.1117/12.2079606