An active remote sensing system is provided with an array of laser diodes that generate light directed to an object having one or more optical wavelengths that include at least one near-infrared wavelength between 700 nanometers and 2500 nanometers. One of the laser diodes pulses with pulse duration of approximately 0.5 to 2 nanoseconds at repetition rate between one kilohertz and about 100 megahertz. A beam splitter receives the laser light, separates the light into a plurality of spatially separated lights and directs the lights to the object. A detection system includes a photodiode array synchronized to the array of laser diodes and performs a time-of-flight measurement by measuring a temporal distribution of photons received from the object. The time-of-flight measurement is combined with images from a camera system, and the remote sensing system is configured to be coupled to a wearable device, a smart phone or a tablet.

An optical system measures one or more physiological parameters with a wearable device that includes a light emitting diode (LED) source including a driver and a plurality of semiconductor sources that generate an output optical light. One or more lenses deliver a lens output light to tissue of a user. A detection system receives at least a portion of the lens output light reflected from the tissue and generates an output signal having a signal-to-noise ratio. The detection system comprises a plurality of spatially separated detectors and an analog to digital converter. The detection system increases the signal-to-noised ratio by comparing a first signal with the LEDs off to a second signal with the LEDs on. An imaging system including a Bragg reflector is pulsed and has a near infrared wavelength. A beam splitter splits the light into a sample arm and a reference arm to measure time-of-flight.

System and apparatus for robust, portable gas detection. Specifically, this disclosure describes apparatuses and systems for optical gas detection in a compact package using two optical pathways. There is a need for a very compact, low-power, gas detection system for gases such as CO2, NOx, water vapor, methane, etc. This disclosure provides an ultra-compact and highly stable and efficient optical measurement system based on principals of optical absorption spectroscopy using substantially collinear pathways.

A system and method indicate capability for detecting methane leaks inside buildings. This approach provides the ability to detect methane behind high efficiency coated windows and can extract methane concentration (rather than concentration-path length product CL). Lock-in imaging technologies can facilitate lower laser transmitter power. A field deployable, hand held prototype sensor for use in remote sensing a appropriate standoff distances can support operational testing. Distance infrared imaging of methane is feasible. Fully characterized real time image of a methane cloud offers operational advantages in accuracy and safety as compared to current sensors.

A gas sensor for measuring concentration of a predetermined gas includes a light source (2) arranged to emit pulses of light, a measurement volume (10), a detector (4) arranged to receive light that has passed through the measurement volume (10), and an adaptable filter (6) disposed between the light source (2) and the detector (4). The gas sensor has a measurement state in which it passes at least one wavelength band which is absorbed by the gas and a reference state in which said wavelength band is attenuated relative to the measurement state. A controller is connected to each of the light source, the detector and the adaptable filter to change the adaptable filter between one of said measurement state and said reference state to the other at least once during a gas sensor operation period.

A gas detection that includes a projector including a light source that emits laser light having a wavelength at which an absorption rate by a detection target gas is high and a spatial light modulator that modulates the laser light emitted from the light source, a projection control unit that controls projection light to be projected toward a retroreflector by causing the light source to emit the laser light and setting a pattern of a modulation part of the spatial light modulator, a light receiver that receives reflected light of the projection light reflected by the retroreflector and measures an intensity of the received reflected light; and a leakage determination unit that acquires the intensity of the reflected light from the light receiver and determines leakage of the detection target gas in a detection space with the retroreflector based on the intensity of the reflected light.

Systems, devices and methods including a handheld sensing device comprising: a sensor configured to measure ambient methane, ethane, propane, butane, and/or pentane concentrations; and a handle, where the sensor is disposed on a first end of the handle; control electronics comprising: a processor having addressable memory, the processor in communication with the sensor, where the processor is configured to: receive the measured ambient gas concentrations; and detect elevated ambient gas concentrations that may be attributed to a natural gas emissions source based on the measured ambient gas concentrations.

A gas sensor module (100) includes an infrared light emitting diode (10) configured to emit infrared light in accordance with a drive current, a quantum infrared sensor (20) configured to detect infrared light that passes through a detection target gas, a drive circuit (30) configured to output the drive current to the infrared light emitting diode (10), a charging circuit (50) to be connected to a power source and configured to output a charge current having a smaller current amount than the drive current, and a capacitor (40) configured to charge by the charge current being supplied from the charging circuit (50) and discharge by supplying the drive current to the drive circuit (30).

An optical system measures one or more physiological parameters with a wearable device that includes a light emitting diode (LED) source including a driver and a plurality of semiconductor sources that generate an output optical light. One or more lenses deliver a lens output light to tissue of a user. A detection system receives at least a portion of the lens output light reflected from the tissue and generates an output signal having a signal-to-noise ratio. The detection system comprises a plurality of spatially separated detectors and an analog to digital converter. The detection system increases the signal-to-noised ratio by comparing a first signal with the LEDs off to a second signal with the LEDs on. An imaging system including a Bragg reflector is pulsed and has a near infrared wavelength. A beam splitter splits the light into a sample arm and a reference arm to measure time-of-flight.

Methods, apparatuses, and systems for improving gas detecting devices are provided. An example gas detecting device may include a receiver element. In some examples, the receiver element may include a sample filter component and a reference filter component. In some examples, the sample filter component may be positioned coaxially with the reference filter component.