Abstract: Chalcogenide waveguides with high width-to-height aspect ratios and a smooth exposed surfaces can serve as mid-infrared evanescent-absorption-based sensors for detecting and identifying volatile organic compounds and/or determining their concentration, optionally in real-time. The waveguide sensors may be manufactured using a modified sputtering process in which the sputtering target and waveguide substrate are titled and/or laterally offset relative to each other and the substrate is continuously rotated.

Abstract: Chalcogenide waveguides with high width-to-height aspect ratios and a smooth exposed surfaces can serve as mid-infrared evanescent-absorption-based sensors for detecting and identifying volatile organic compounds and/or determining their concentration, optionally in real-time. The waveguide sensors may be manufactured using a modified sputtering process in which the sputtering target and waveguide substrate are titled and/or laterally offset relative to each other and the substrate is continuously rotated.

Abstract: A photonic biosensor including a biological probe disposed on a mid-infrared-transparent waveguide can be used to detect biological analytes in biological samples, using specific binding of the analyte to the probe in conjunction with absorption spectroscopy. In various embodiments, the biosensor is used for molecular diagnostics, e.g., to detect oligonucleotides or proteins associated with a coronavirus.

Abstract: Raman spectroscopy of chemical and biological samples can be accomplished with photonic sensors amenable to chip-scale integration. In various embodiments, such a photonic sensor includes first and second optical waveguides coupled via an optical ring resonator, the ring resonator configured to resonantly enhance, and selectively couple into the second optical waveguide, a Raman scattering signal generated, when the first waveguide and/or resonator are exposed to a sample, by interaction of an analyte in the sample with excitation light coupled into the first optical waveguide.

Abstract: A waveguide structure including a mid-infrared-transparent waveguide on a mid-infrared-transparent undercladding may serve as a photonic chemical sensor for measuring characteristic absorptions of analytes brought in physical contact with the waveguide. In some embodiments, a sensor including an amorphous-silicon waveguide on a barium-titanate undercladding can operate at wavelengths ranging from 2.5 ?m to about 7 ?m; this sensor may be manufactured by epitaxial growth of the undercladding on a substrate, followed by CMOS-compatible creation of the waveguide. Additional embodiments are disclosed.

Abstract: Chalcogenide waveguides with high width-to-height aspect ratios and a smooth exposed surfaces can serve as mid-infrared evanescent-absorption-based sensors for detecting and identifying volatile organic compounds and/or determining their concentration, optionally in real-time. The waveguide sensors may be manufactured using a modified sputtering process in which the sputtering target and waveguide substrate are titled and/or laterally offset relative to each other and the substrate is continuously rotated.

Abstract: A flexible waveguide structure including a waveguide on a flexible substrate, both having transparent windows in the mid-infrared range, may serve as a photonic chemical sensor for measuring characteristic absorptions of analytes brought in physical contact with the waveguide. Such a sensor may, in accordance with some embodiments, be formed by an aluminum-nitride waveguide on a borosilicate substrate.

Abstract: A sensing apparatus includes a light source to transmit a light beam, an input switch, a first sensing element, a second sensing element, and a detector. The input switch receives the light beam and includes a phase change material having a first state and a second state. The first sensing element receives the light beam from the input switch when the phase change material is in the first state and produces a first change in the light beam in response to a presence of a first analyte. The second sensing element receives the light beam from the input switch when the phase change material is in the second state and produces a second change in the light beam in response to a presence of a second analyte. The detector detects the first change and/or the second change in the light beam.

Abstract: A flexible waveguide structure including a waveguide on a flexible substrate, both having transparent windows in the mid-infrared range, may serve as a photonic chemical sensor for measuring characteristic absorptions of analytes brought in physical contact with the waveguide. Such a sensor may, in accordance with some embodiments, be formed by an aluminum-nitride waveguide on a borosilicate substrate.

Abstract: A waveguide structure including a mid-infrared-transparent waveguide on a mid-infrared-transparent undercladding may serve as a photonic chemical sensor for measuring characteristic absorptions of analytes brought in physical contact with the waveguide. In some embodiments, a sensor including an amorphous-silicon waveguide on a barium-titanate undercladding can operate at wavelengths ranging from 2.5 ?m to about 7 ?m; this sensor may be manufactured by epitaxial growth of the undercladding on a substrate, followed by CMOS-compatible creation of the waveguide. Additional embodiments are disclosed.

Abstract: A method for lithographic patterning of thin films. A thin film is deposited on a substrate and the film is exposed to optical energy from a focused laser to induce a thermal gradient in the film by optical absorption. The film is softened through a melting or glass transition process and the thermal gradient induces a directional dewetting down the thermal gradient. The invention permits developer free positive tone lithography by thermal direct write and also metrology of the thin film by the morphology of the resultant features.

Abstract: A device includes a substrate, a pedestal extending from the substrate, and a ring resonator disposed on the pedestal above the substrate. The ring resonator has a resonance wavelength greater than 1.5 ?m and includes at least one of silicon and chalcogenide glass. The device can be used as a ring resonator sensor or a light source. The ring resonator is substantially transparent to mid-infrared radiation to reduce optical losses. The pedestal has a narrower width compared to the ring resonator to generate improved interaction between evanescent fields of light in the ring resonator and analytes nearby the ring resonator, thereby increasing sensing sensitivity. In addition, fabrication of the device is compatible with complementary metal-oxide-semiconductor (CMOS) processes and hence is amenable to large scale manufacturing.

Abstract: A sensing apparatus includes a light source to transmit a light beam, an input switch, a first sensing element, a second sensing element, and a detector. The input switch receives the light beam and includes a phase change material having a first state and a second state. The first sensing element receives the light beam from the input switch when the phase change material is in the first state and produces a first change in the light beam in response to a presence of a first analyte. The second sensing element receives the light beam from the input switch when the phase change material is in the second state and produces a second change in the light beam in response to a presence of a second analyte. The detector detects the first change and/or the second change in the light beam.

Abstract: A device includes a substrate, a pedestal extending from the substrate, and a ring resonator disposed on the pedestal above the substrate. The ring resonator has a resonance wavelength greater than 1.5 ?m and includes at least one of silicon and chalcogenide glass. The device can be used as a ring resonator sensor or a light source. The ring resonator is substantially transparent to mid-infrared radiation to reduce optical losses. The pedestal has a narrower width compared to the ring resonator to generate improved interaction between evanescent fields of light in the ring resonator and analytes nearby the ring resonator, thereby increasing sensing sensitivity. In addition, fabrication of the device is compatible with complementary metal-oxide-semiconductor (CMOS) processes and hence is amenable to large scale manufacturing.

Abstract: A method for lithographic patterning of thin films. A thin film is deposited on a substrate and the film is exposed to optical energy from a focused laser to induce a thermal gradient in the film by optical absorption. The film is softened through a melting or glass transition process and the thermal gradient induces a directional dewetting down the thermal gradient. The invention permits developer free positive tone lithography by thermal direct write and also metrology of the thin film by the morphology of the resultant features.

Abstract: A chip-scale, air-clad semiconductor pedestal waveguide can be used as a mid-infrared (mid-IR) sensor capable of in situ monitoring of organic solvents and other analytes. The sensor uses evanescent coupling from a silicon or germanium waveguide, which is highly transparent in the mid-IR portion of the electromagnetic spectrum, to probe the absorption spectrum of fluid surrounding the waveguide. Launching a mid-IR beam into the waveguide exposed to a particular analyte causes attenuation of the evanescent wave's spectral components due to absorption by carbon, oxygen, hydrogen, and/or nitrogen bonds in the surrounding fluid. Detecting these changes at the waveguide's output provides an indication of the type and concentration of one or more compounds in the surrounding fluid. If desired, the sensor may be integrated onto a silicon substrate with a mid-IR light source and a mid-IR detector to form a chip-based spectrometer.

Abstract: A chip-scale, air-clad semiconductor pedestal waveguide can be used as a mid-infrared (mid-IR) sensor capable of in situ monitoring of organic solvents and other analytes. The sensor uses evanescent coupling from a silicon or germanium waveguide, which is highly transparent in the mid-IR portion of the electromagnetic spectrum (e.g., between ?=1.3 ?m and ?=6.5 ?m for silicon and ?=1.3 ?m and ?=12.0 ?m for germanium), to probe the absorption spectrum of the fluid surrounding the waveguide. Launching a mid-IR beam into the waveguide exposed to a particular analyte causes attenuation of the evanescent wave's spectral components due to absorption by carbon, oxygen, hydrogen, and/or nitrogen bonds in the surrounding fluid. Detecting these changes at the waveguide's output provides an indication of the type and concentration of one or more compounds in the surrounding fluid.