Abstract: An apparatus for detecting objects comprises an optical interferometer that is configured to receive electromagnetic radiation from a light source, and emit electromagnetic radiation to a detector. The optical interferometer is coupled to an environment and further configured to respond to objects in the environment intruding into an interaction volume of the optical interferometer by varying an intensity of the electromagnetic radiation emitted to the detector based on a property of the objects in the interaction volume. A signal processor is configured to generate an output signal based on the intensity of the electromagnetic radiation emitted to the detector.

Abstract: The particle sensor device comprises a substrate, a photodetector, a dielectric on or above the substrate, a source of electromagnetic radiation, and a through-substrate via in the substrate. The through-substrate via is exposed to the environment, in particular to ambient air. A waveguide is arranged in or above the dielectric so that the electromagnetic radiation emitted by the source of electromagnetic radiation is coupled into a portion of the waveguide. A further portion of the waveguide is opposite the photodetector, so that said portions of the waveguide are on different sides of the through-substrate via, and the waveguide traverses the through-substrate via.

Abstract: The particle sensor device comprises a substrate, a photodetector, a dielectric on or above the substrate, a source of electromagnetic radiation, and a through-substrate via in the substrate. The through-substrate via is exposed to the environment, in particular to ambient air. A waveguide is arranged in or above the dielectric so that the electromagnetic radiation emitted by the source of electromagnetic radiation is coupled into a portion of the waveguide. A further portion of the waveguide is opposite the photodetector, so that said portions of the waveguide are on different sides of the through-substrate via, and the waveguide traverses the through-substrate via.

Abstract: An apparatus for sensing particulate matter in a fluid includes a substrate; and an integrated circuit electrically connected to the substrate, the integrated circuit including a photodetector. The apparatus includes a filter assembly including a particle filter aligned with the photodetector, and a filter housing for the particle filter, the filter housing defining a flow path for fluid through the particle filter. The apparatus includes a light source electrically connected to the substrate and positioned to illuminate the particle filter.