An acoustic wave detector may include: an exterior housing with an exterior housing wall, a gas chamber located within the exterior housing and configured to receive a gas therein. The exterior housing wall may include an aperture providing a gas passage between the gas chamber and the exterior of the acoustic wave detector. The acoustic wave detector may further include an excitation element configured to selectively excite gas molecules of a specific type in the gas received in the gas chamber in a time-varying fashion, thereby generating acoustic waves in the gas, and an acoustic wave sensor configured to detect the acoustic waves generated in the gas and acoustic waves generated outside of the acoustic wave detector. The acoustic wave sensor may have an acoustic port overlapping with the aperture in the exterior housing wall.

The invention relates to a device for detecting a gaseous species by photoacoustic effect. The device comprises a substrate, inside which a cavity is formed. A light source is disposed on the substrate, in such a way that a part of the substrate extends between the light source and the cavity. The device is arranged in such a way that the light, emitted by the light source, is propagated through the substrate, before reaching the cavity.

Provided is a concentration measurement apparatus for measuring a concentration of a measurement object using an infrared ray, the concentration measurement apparatus including a signal acquisition unit configured to acquire a detection signal, a temperature information acquisition unit configured to acquire temperature information, a correction unit configured to output a correction signal obtained by correcting a temperature dependency of the detection signal based on the temperature information, and a calculation unit configured to calculate the concentration of the measurement object according to the correction signal using calibration curve data at a predetermined reference temperature for calculating the concentration of the measurement object, in which the correction unit is configured to output the correction signal obtained by performing linear correction of the detection signal using, among predetermined correction parameters different for three or more respective temperature segments, the correction parameter in a temperature segment corresponding to the temperature information.

The invention relates to a modulatable infrared emitter comprising an aperture structure, a structured micro-heating element, and an actuator, wherein the aperture structure and the structured micro-heating element are movable relative to each other in parallel planes by means of the actuator to modulate the intensity of emitted infrared radiation. The invention further relates to methods of manufacturing the infrared emitter, a method of modulating emission of infrared radiation using the infrared emitter, and preferred uses of the infrared emitter. In further aspects the invention relates to a system comprising the infrared emitter and a control device for regulating the actuator.

A semiconductor device disclosed in an embodiment comprises: a light emitting unit comprising a light emitting structure layer which has a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; and a sensor unit disposed on the light emitting unit, wherein the sensor unit comprises: a sensing material changing in resistance with light emitted by the light emitting unit; a first sensor electrode comprising a first pad portion and a first extension part extending from the first pad portion and contacting the sensing material; and a second sensor electrode comprising a first pad portion and a second extension part extending toward the first extension part from the second pad portion and contacting the sensing material. The sensor unit senses an external gas in response to the light generated from the light emitting unit.

A gas sensor includes: an outer housing having an outer housing gas inlet and an outer housing gas outlet for receiving a flow of gas; and an inner housing disposed within the outer housing such that a gas flow passage is defined through the gas sensor between the inner housing and the outer housing to allow gas to enter the outer housing gas inlet and exit the outer housing gas outlet. The inner housing is provided with an inner housing gas inlet and an inner housing gas outlet each in fluid communication with the gas flow passage. The inner housing gas inlet and inner housing gas outlet are positioned relative to the gas flow passage such that when gas flows through the gas flow passage there is a pressure gradient across the inner housing gas inlet and inner housing gas outlet which causes gas to pass through the inner housing.

A thermal emitter includes a freestanding membrane supported by a substrate, wherein the freestanding membrane includes in a lateral extension a center section, a conductive intermediate section and a border section, wherein the conductive intermediate section laterally surrounds the center section and is electrically isolated from the center section, the conductive intermediate section including a conductive semiconductor material that is encapsulated in an insulating material, wherein the border section at least partially surrounds the intermediate section and is electrically isolated from the conductive intermediate section, and wherein a perforation is formed through the border section.

A light emitter device includes an emitter component including a heater structure arranged on a membrane structure. The membrane structure is located above a first cavity. Additionally, the first cavity is located between the membrane structure and at least a portion of a supporting substrate of the emitter component. Further, the heater structure is configured to emit light, if a predefined current flows through the heater structure. Additionally, the light emitter device includes a lid substrate having a recess. The lid substrate is attached to the emitter component so that the recess forms a second cavity between the membrane structure and the lid substrate. Further, a pressure in the second cavity is less than 100 mbar.

A method for detecting of components in a fluid includes emitting a modulated light beam from a modulated light source to the fluid in a chamber, wherein the fluid comprises a liquid and a component in the liquid. The method includes producing an acoustic signal in response to the emitted modulated light beam and detecting the acoustic signal via a pressure sensor disposed in the chamber. The method in one example also includes transmitting the acoustic signal from the pressure sensor to a processor based module and determining at least one of a component and a concentration of the component in the fluid via the processor based module, based on the acoustic signal.

A light emitting structure for a photo-acoustic spectroscopy sensing device for sensing a target gas comprises a light source configured for emitting light of an input wavelength. The light emitting structure further comprises a conversion structure that is configured for absorbing light of the input wavelength, and that is further configured for emitting light of an output wavelength. The output wavelength of the conversion structure is adapted to an absorption wavelength of the target gas. The conversion structure comprises an output conversion layer that comprises a plurality of nanoparticles. The nanoparticles of the output conversion layer are configured for emitting light of the output wavelength.