Apparatuses, methods, and systems for generating signatures based on sensing one or more gas concentration conditions are disclosed. One method includes sensing, by one or more sensors, levels of a gas over time for a plurality of gas concentration conditions, receiving, by a controller, the sensed levels of gas over time for the plurality of gas concentration conditions, and generating, by the controller, a plurality of signatures, wherein one or more signatures is generated for one or more gas concentration conditions based on the sensed levels of gas over time, and determining whether to take action or not to take action.

Devices, systems, and methods for determining gas characteristics to monitor transformer operation include extracting gas from transformer fluid for analysis.

The present invention relates to a novel analysis device and method for obtaining the concentration of dissolved inorganic carbon (DIC) and isotopic carbon and oxygen concentration thereof, continuously from a liquid sample.

Systems and methods for controlling optical feedback in an optical system having a radiation source optically coupled via mode matching optics with a resonant optical cavity. The cavity includes at least two cavity mirrors, one of which is a cavity coupling mirror, and has a plurality of optical resonance cavity modes, wherein the radiation source emits a beam of continuous wave radiation and is capable of being scanned whereby a mean optical frequency of the continuous wave radiation beam is adjustable over a range of frequencies, wherein the radiation source is responsive to optical feedback radiation emerging from the cavity, and wherein the mode matching optics couples the beam of continuous wave radiation to the cavity via the cavity coupling mirror. The radiation source and the mode matching optics are aligned so that a mode fill ratio is reduced relative to a maximum mode fill ratio, wherein for the maximum mode-fill ratio the laser beam is coupled with a fundamental cavity mode.

An optical system uses a sample medium disposed within an optical cavity, receives an input beam that may be non-coherent or coherent, and produces an optical energy from the input beam, by creating birefringent-induced beam components each cavity traversal, forming a mixed quantum state beam for the input beam. The mixed quantum state beam exits the cavity, and the energy distribution of the exiting beam is analyzed over a range of tuned input beam frequencies to uniquely identify circularly birefringent the materials within the sample medium, e.g., amino acids, proteins, or other circular birefringent molecules, biological or otherwise.

A fluid analyzer includes a substrate, a quantum cascade laser formed on a surface of the substrate and including a first light-emitting surface and a second light-emitting surface facing each other in a predetermined direction parallel to the surface, a quantum cascade detector formed on the surface and including the same layer structure as the quantum cascade laser and a light incident surface facing the second light-emitting surface in the predetermined direction, and an optical element disposed on an optical path of light emitted from the first light-emitting surface across an inspection region in which a fluid to be analyzed is to be disposed and reflecting the light to feed the light back to the first light-emitting surface.

Devices, systems, and methods for determining gas characteristics to monitor transformer operation include extracting gas from transformer fluid for analysis.

Interleaved data acquisition in optical spectroscopy is used to provide interference correction for time-varying interference. Measurements at a reference frequency are used to provide an estimate of the interference. These reference measurements are interleaved with the remaining measurements in order to provide estimates of the interference vs. time at relevant times. The interference being corrected can be spectrally structured or unstructured.

Systems and methods for controlling optical feedback in an optical system having a radiation source optically coupled via mode matching optics with a resonant optical cavity. The cavity includes at least two cavity mirrors, one of which is a cavity coupling mirror, and has a plurality of optical resonance cavity modes, wherein the radiation source emits a beam of continuous wave radiation and is capable of being scanned whereby a mean optical frequency of the continuous wave radiation beam is adjustable over a range of frequencies, wherein the radiation source is responsive to optical feedback radiation emerging from the cavity, and wherein the mode matching optics couples the beam of continuous wave radiation to the cavity via the cavity coupling mirror. The radiation source and the mode matching optics are aligned so that a mode fill ratio is reduced relative to a maximum mode fill ratio, wherein for the maximum mode-fill ratio the laser beam is coupled with a fundamental cavity mode.

Systems and methods for detecting trace gases utilize a resonance optical cavity and one, two or more coherent light sources coupled to the cavity through one or more cavity coupling mirrors, whereby two or more optical cavities may share the same gas volume.