TY - JOUR
T1 - Characterization of Evanescent Field Gas Sensor Structures Based on Silicon Photonics
AU - Ranacher, Christian
AU - Consani, Cristina
AU - Vollert, Natalie
AU - Tortschanoff, Andreas
AU - Bergmeister, Markus
AU - Grille, Thomas
AU - Jakoby, Bernhard
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Photonic sensors that operate in the mid-infrared spectral range are an emerging field for photonic microsystems. In this paper, we present a photonic gas sensor concept based on silicon waveguides using infrared evanescent field absorption. The waveguides were specifically designed for CO2 sensing at a wavelength of λ =4.26 μ m as possible application for the proposed sensor platform. The waveguide cross section as well as the substructure were investigated using finite-element simulations and the devised structures were fabricated using mass fabrication processes exclusively. In order to evaluate the potential for long interaction path lengths using polysilicon strip waveguides, a study on the intrinsic losses of polysilicon waveguides was conducted. The lowest intrinsic damping that was obtained for polysilicon strip waveguides was 3.98 dB/cm. Furthermore, the sensing capability of the devised waveguides was tested with quantitative CO2 measurements down to a concentration of 500 ppm CO2. From the quantitative measurements, the evanescent field ratio was estimated and was in the range between η =14%-16%.
AB - Photonic sensors that operate in the mid-infrared spectral range are an emerging field for photonic microsystems. In this paper, we present a photonic gas sensor concept based on silicon waveguides using infrared evanescent field absorption. The waveguides were specifically designed for CO2 sensing at a wavelength of λ =4.26 μ m as possible application for the proposed sensor platform. The waveguide cross section as well as the substructure were investigated using finite-element simulations and the devised structures were fabricated using mass fabrication processes exclusively. In order to evaluate the potential for long interaction path lengths using polysilicon strip waveguides, a study on the intrinsic losses of polysilicon waveguides was conducted. The lowest intrinsic damping that was obtained for polysilicon strip waveguides was 3.98 dB/cm. Furthermore, the sensing capability of the devised waveguides was tested with quantitative CO2 measurements down to a concentration of 500 ppm CO2. From the quantitative measurements, the evanescent field ratio was estimated and was in the range between η =14%-16%.
KW - Optical gas sensing
KW - evanescent field absorption
KW - integrated silicon photonics
KW - intrinsic losses.
KW - silicon waveguide
UR - https://www.mendeley.com/catalogue/1f1c79e6-df4a-32d6-b1d9-118bdb9c5370/
U2 - 10.1109/JPHOT.2018.2866628
DO - 10.1109/JPHOT.2018.2866628
M3 - Article
SN - 1943-0655
VL - 10
JO - IEEE Photonics Journal
JF - IEEE Photonics Journal
IS - 5
ER -