A stacked optical filter arrangement includes a pneumatic liquid crystal layer stacked between a first and second transparent electrode layers, wherein the first transparent electrode layer includes electrode segments that are isolated from each other; first and second polarizer layers, wherein the pneumatic liquid crystal layer is stacked between the first polarizer layer and the second polarizer layer; a filter layer including filter segments, wherein at least two of the filter segments are wavelength sensitive filter segments, wherein at least two of the wavelength sensitive filter segments are transparent for different wavelengths; and optical channels, wherein each optical channel includes a portion of the pneumatic liquid crystal layer, a portion of the first electrode layer, one of the plurality of electrode segments of the second transparent electrode layer, a portion of the first polarizer layer, a portion of the second polarizer layer, and one of the plurality of filter segments.

A photo-acoustic gas sensor may include a detector component. The detector component includes a package that defines a reference volume. The reference volume houses a reference gas. The detector component includes a pressure sensing element to measure an amount of pressure in the reference volume. The amount of pressure in the reference volume depends on absorption of a wavelength of light by the reference gas in the reference volume. A sensitivity of the pressure sensing element when measuring the amount of pressure in the reference volume depends on a length of a reference path associated with the reference volume. The detector component includes a reference path structure that causes the length of the reference path to be less than or equal to 0.5 millimeters.

A photoacoustic gas sensor includes a hermetically sealed housing filled with a reference gas. The photoacoustic gas sensor furthermore includes a microphone arranged in the housing and configured to generate a microphone signal as a function of a sound wave based on light incident in the housing. Furthermore, the photoacoustic gas sensor includes a controllable heat source arranged in the housing and configured to selectively thermoacoustically excite the reference gas in order to generate a thermoacoustic sound wave phase-shifted with respect to the sound wave.

A method of detecting a species, strain or type of bacteria includes mixing a labeled bacteriophage including a label that is detectible via a detection system with a bacterial culture including the species, strain or type of bacteria to which the labeled bacteriophage selectively binds and using the detection system to detect the labeled bacteriophage bound to the species, strain or type of bacteria.

A photo-acoustic gas sensor using a method for modulating the wavelength of the laser radiation, the modulation being obtained via judicious use of an electric current, called the generation current, which pumps the one or more laser sources, and is configured to cause the one or more laser sources to operate in pulsed mode, and of a current, called the base current, which takes non-zero values between each laser pulse with a lower magnitude than the magnitude of the generation current, the magnitude of base current being modulated so that the one or more laser sources emit, into the cell, light radiation having a wavelength that varies periodically about a central wavelength so as to take, at regular intervals, a value specifically suitable for the excitation of a gas to be detected, whereby an interaction between the light radiation and the gas to be detected contained in the cell induces the generation of acoustic waves at a resonant frequency of the cell.

A photoacoustic device for detecting gas includes a photoacoustic cavity having a side wall extending between a first end and a second end and having an outer surface; a light source suitable for emitting a modulated light radiation, and coupled to the first end; a microphone coupled to the side wall, the photoacoustic cavity being made of a material transparent to the light radiation of the light source; a mirror being arranged on at least one portion of the outer surface of the side wall; and the side wall having a thickness chosen as a function of the depth of penetration δ of a thermal wave coming from the mirror into the transparent material.

The present invention relates to a sensor wiring substrate in which a decrease in detection accuracy is suppressed, a sensor package, and a sensor device. A gas sensor wiring substrate includes a substrate having a first accommodation recessed portion for accommodating a microphone element and a second accommodation recessed portion for accommodating an infrared light emitting element, and connection wiring. In the gas sensor wiring substrate, thermal resistance of a heat transfer path between a bottom surface of the first accommodation recessed portion and a bottom surface of the second accommodation recessed portion is greater than thermal resistance in any position of an imaginal heat transfer path in case of a depth of the first accommodation recessed portion identical with a depth of the second accommodation recessed portion. For example, the depth of the second accommodation recessed portion is deeper than the depth of the first accommodation recessed portion.

Photoacoustic detecting device (1), intended to be applied, via a contact face (3), against a medium to be analysed, the device comprising: a hollow cavity (20) comprising a first aperture (22) produced in the contact face, the cavity being bounded by a containment shell (21) that extends around the first aperture; a pulsed or amplitude-modulated light source (10) configured to emit, in an emission spectral band (Δλ), an incident light wave (11) through the cavity (20) to the first aperture; an acoustic transducer (28) linked to the cavity and configured to detect a photoacoustic wave (12) extending through the cavity.

The photoacoustic detecting device is optimized to increase the amplitude of the photoacoustic wave detected by the acoustic transducer.

Photoacoustic gas sensor having a light pulse emitter, a microphone in a reference gas housing having a reference gas, and a sample gas housing to be filled with a gas to be analyzed. A wall separates the sample gas housing from the reference gas housing, and has a transparent region that is transparent to light within a frequency range of emitted light pulses. Remaining inner walls of the sample gas housing have a reflecting surface that reflect light pulses emitted by the emitter so that a portion of the light pulses not absorbed by the gas to be analyzed pass through the transparent region into the reference gas volume. The microphone generates a sensor signal indicating information on an acoustic wave caused by the light pulses interacting with the reference gas after crossing the gas to be analyzed.

A photoacoustic detection system (20) includes a detector (22) that has a chamber (24), a pulsed light source (26), piezoelectric tuning forks (28), and a photosensor (30). The chamber has an inlet and an outlet for flow of an analyte. The pulsed light source is adjacent the chamber and is operable to emit a light beam along a path through the chamber. The tuning forks are arranged along the path, and each of the tuning forks is operable to emit first sensor signals. The photosensor is arranged along the path and is operable to emit second sensor signals. A controller (38) is connected to receive the first and second sensor signals. The controller is configured to determine whether a target species is present in the analyte based on the first sensor signals and determine whether the target species is present in the analyte based on the second sensor signals.