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We show detection of CO2 concentrations as low as 500 ppm using a suspended silicon photonic mid-IR waveguide. The performance is enabled by the low propagation loss (2.35 ±0.25) dB/cm permitting sensing with waveguides up to 7 cm in length., Part of ISBN 9781557528209QC 20230622

A device (1) and a method for fabricating such a device is described. The device (1) comprises a device layer (4), a substrate (2) defining a substrate plane (3). A device layer plane (5) is defined on the side of the device layer (4) facing the substrate (2). The device also comprises a waveguide (7) for guiding an electromagnetic wave. The waveguide (7) is supported on the substrate (2) via a support structure (6) extending from the substrate (2) to the device layer (4). The ratio of the largest distance (D1), perpendicular to the substrate plane (3), between a free surface of the waveguide (7) facing the substrate and any solid material to the height (h) of the waveguide (7) is more than 6, i.e. D1/h \textgreater 6. The ratio of the distance (D2), perpendicular to the substrate plane (3), between the device layer plane (5) and the substrate plane (3) to the height (h) of the waveguide (7) is more than 6, i.e. D2/h \textgreater 6., Library Catalog: ESpacenetQC 20210113

A sensor device comprising a planar substrate defining a substrate plane and a waveguide for guiding an electromagnetic wave. The waveguide extends in a length direction in a waveguide plane parallel to the substrate plane and has a width and a height wherein the width to height ratio is more than 5. The height of the waveguide is less than the wavelength of the electromagnetic wave. The waveguide is supported on the substrate by a support structure extending from the substrate to the waveguide, along the length direction of the waveguide, having a width which is smaller than the width of the waveguide. The invention further relates to a method of detecting a component in gas and a method of fabricating a sensor device., QC 20210226

Carbon dioxide (CO2) is a gas vital for life on Earth. It is also a waste product of human activities and is widely used in agriculture and industry. Its accurate sensing is therefore of great interest. Optical sensors exploiting the mid-infrared light absorption of CO2 provide high selectivity, but their large size and high cost limit their use. In this Letter, we demonstrate CO2 gas sensing at 4.2 µm wavelength using an integrated silicon waveguide, featuring a sensitivity to CO2 of 44% that of free-space sensing. The suspended waveguide is fabricated on a silicon-on-insulator substrate by a single-lithography-step process, and we route it into a mid-infrared photonic circuit for on-chip-referenced gas measurements. Its demonstrated performance and its simple and scalable fabrication make our waveguide ideal for integration in miniaturized CO2 sensors for distributed environmental monitoring, personal safety, and medical and high-volume consumer applications.

We demonstrate on-chip molecular fingerprinting by measuring the refractive index dispersion of gas in the mid-IR using a thermally tuned suspended silicon microring resonator. We show CO2 sensing down to 1000 ppm at 4.23 µm wavelength., QC 20210916

We review our recent work on spectroscopic sensing of carbon dioxide in the mid-infrarded region around 4.3 µm using suspended silicon waveguides. Our waveguides are built on standard silicon-on-insulator substrates and acheive high sensitivity to gas., Part of proceedings: ISBN 9781557528209, QC 20220613

We present a low-confinement Si waveguide for 4.26 μm wavelength and apply it to sense CO2 concentrations down to 0.1 %. We demonstrate the highest reported waveguide sensitivity to CO2: 44 % of the free-space sensitivity., SyskonpostNot duplicate with DIVA 1327380QC 20211012

This paper reports the first optical shutter based on electrical actuation of microdroplets featuring zero insertion loss in the open state and broad-band operation. These features are achieved by electrowetting-on-dielectric (EWOD) actuation of ionic liquid microdroplets. Due to their negligible vapor pressure, ionic liquids allow the switch to robustly operate in air, unlike previously proposed systems in which the light had to cross several attenuating and refractive layers. Moreover, this solution enables operation in a much wider wavelength range, e.g. in the infrared spectrum where glass has strong absorption. Additionally, the proposed device requires lower voltage to operate (25 V) and features zero static power consumption., QC 20200717

We present a low-confinement Si waveguide for 4.26 μm wavelength and applyit to sense CO2 concentrations down to 0.1 %. We demonstrate the highest reportedwaveguide sensitivity to CO2: 44% of the free-space sensitivity., QC 20190802

This article reports a broad-band optical shutter based on microdroplet actuation with zero optical insertion loss in the open state. These features are achieved by electrowetting-on-dielectric (EWOD) actuation of opaque ionic liquid microdroplets. The negligible vapor pressure of ionic liquids allows the device to robustly operate in open air, unlike previously proposed EWOD-based systems in which the light crosses several attenuating and reflective layers, preventing broad-band operation and creating insertion losses > 14%. The presented device provides an attenuation of 78dB in the closed state and a transmission of >99.99999% in the open state and can operate in the visible and mid-infrared wavelength range. Moreover, the switch can sustain larger incoming laser powers (5 mW continuous exposure or up to 3h of continuous exposure at similar to 100mW) compared to the values reported for other state-of-the-art EWOD-based shutters. Additionally, the proposed device is compact, operates with low voltage (<25V peak voltage), and features zero static power consumption., QC 20190912

A method for fabrication of a device (100) with an elongated structure (5), extending in a length direction (L) in a device layer (2) is described. The method comprises the steps of providing a planar first layer (1) on which the device layer (2) is supported, removing material in the device layer (2) to provide a first set of openings (3) through the device layer (2), and removing material from the planar first layer (1) under the elongated structure (5) through the first set of openings (3), wherein he arrangement of the first set of openings (3) is such that said support structure (4) is formed on which the elongated structure (5) is supported. The method also comprises the step of removing material from the device layer (2) to form the elongated structure (5) delimited by side surfaces (6)., QC 20210209

QC 20190624

We demonstrate the first uncooled single-nanowire-based infrared bolometer to detect sub-mW optical signals up to MHz frequencies. The bolometer consists of a Pt nanowire on a suspended silicon hybrid-plasmonic cavity, and exhibits enhanced optical responsivity compared to nanowires on unstructured and non-suspended substrates. Low-cost monolithically integrated infrared detectors are needed for the rapidly growing field of silicon photonic sensors. The high speed of our nanobolometer enables advanced modulation schemes for noise reduction and avoidance of low-frequency thermal cross-talk, as well as power saving by pulsed operation. Furthermore, its simple integration and small footprint make it a cost effective detector for sensing applications., QC 20170124

Metal nanowires can emit coherent polarized thermal radiation, work as uncooled bolometers, and provide localized heating. In this paper, we engineer the temperature dynamics of electrically driven Pt nanoheaters on a silicon-on-insulator substrate. We present three designs and we electrically characterize and model their thermal impedance in the frequency range from 3 Hz to 3 MHz. Finally, we show a temperature modulation of 300 K while consuming less than 5 mW of power, up to a frequency of 1.3 MHz. This result can lead to significant advancements in thermography and absorption spectroscopy., QC 20160523

A sensor device comprising a planar substrate defining a substrate plane and a waveguide for guiding an electromagnetic wave. The waveguide extends in a length direction in a waveguide plane parallel to the substrate plane and has a width and a height, wherein the width to height ratio is more than 5. The height of the waveguide is less than the wavelength of the electromagnetic wave. The waveguide is supported on the substrate by a support structure extending from the substrate to the waveguide, along the length direction of the waveguide, having a width which is smaller than the width of the waveguide. The invention further relates to a method of detecting a component in gas and a method of fabricating a sensor device., QC 20191211

We present a method to characterize the temperature dynamics of miniaturized thermal IR sources. The method circumvents the limitations of current IR photodetectors, by relying only on an electrical measurement rather than on optical detection. Thus, it enables the characterization of the light emission of IR sources over their full operation frequency range. Moreover, we develop a model of thermal IR sources allowing simulations of their thermal and electrical behavior. By combining measurements and modeling, we achieve a comprehensive characterization of a Pt nanowire IR source: the reference resistance R-0 = 17.7 Omega, the TCR alpha = 2.0 x 10(-3) K-1, the thermal mass C = 2.7 x 10(-14) J/K, and the thermal conductance G = 1.3 x 10(-6) W/K. The thermal time constant could not be measured, because of the frequency limitation of our setup. However, the operation of the source has been tested and proved to function up to 1 MHz, indicating that the thermal time constant of the source is smaller than 1 mu s., QC 20140813, GASENS

QC 20191011

QC 20191011

Carbon dioxide is a vital gas for life on Earth, a waste product of human activities, and widely used in agriculture and industry. Its accurate sensing is therefore of great interest. Optical sensors exploiting the mid-infrared light absorption of CO2 provide high selectivity, but their large size and high cost limit their use. Here, we demonstrate CO2 gas sensing at 4.2 μm wavelength using an integrated silicon waveguide, featuring a sensitivity to CO2 of 44% that of free-space sensing. The suspended waveguide is fabricated on a silicon-on-insulator substrate by a single-lithography-step process, and we route it into a mid-infrared photonic circuit for on-chip-referenced gas measurements. Its demonstrated performance and its simple and scalable fabrication make our waveguide ideal for integration in miniaturized CO2 sensors for distributed environmental monitoring, personal safety, medical, and high-volume consumer applications., QC 20191011