公开(公告)号：US12259318B2

公开(公告)日：2025-03-25

申请号：US17627298

申请日：2020-07-16

Applicant: Mirico Limited

Inventor： James Hobby ,  Damien Weidmann ,  Richard Kovacich

IPC: G01N21/3504 ,  G01J3/433 ,  G01N21/39 ,  G01J3/42

Abstract: The invention provides a chirped laser dispersion spectrometer having two tunable lasers each with a bias current supply, a chirp signal source to provide a matching chirp pattern, a beam splitter to produce a single beam from the two first and second tunable lasers and active-phase locking means to render the two beams phase coherent and to produce a radio frequency carrier signal capable of programmable phase modulation by means of an optical beat signal. The invention also provides a method for generating at least two optical frequency signals for use in a frequency modulation spectroscopy (FMS) process for the detection and/or measurement of molecular species in a gas mixture and a method for generating at least two optical frequency signals for use in a chirped laser dispersion spectroscopy (CLaDS) process for the detection and/or measurement of molecular species in a gas mixture. The invention provides an efficient and cost-effective CLaDS system which maintains optical modulation whilst enabling greater change of the modulation frequency.

公开(公告)号：US20250067599A1

公开(公告)日：2025-02-27

申请号：US18721164

申请日：2022-12-19

Applicant: UNIVERSITY OF SOUTH FLORIDA

Inventor： Ashwin PARTHASARATHY ,  Sadhu MOKA ,  Abdul Mohaimen SAFI

IPC: G01J3/433 ,  A61B5/026 ,  A61B5/145 ,  A61B5/1455 ,  G01J1/44 ,  G01J3/02 ,  G01J3/44

Abstract: Systems, methods, and apparatus for frequency domain diffuse correlation spectroscopy are provided. In some embodiments, the system comprises: an intensity modulated coherent light source; a photon counting detector; at least one hardware processor that is programmed to: cause the light source to emit light at a plurality of different intensity modulation frequencies toward a tissue sample; detect, for each of the plurality of different modulation frequencies, photon counts over a predetermined period of time; determine, for each of the plurality of modulation frequencies, a normalized intensity auto-correlation function; estimate a plurality of properties of the tissue sample using the plurality of intensity auto-correlation functions; and output at least one of the plurality of properties.

公开(公告)号：US11953434B2

公开(公告)日：2024-04-09

申请号：US17432665

申请日：2020-02-21

Applicant: The Trustees of Princeton University

Inventor： Mark Zondlo ,  Lei Tao ,  Da Pan ,  Josh Collins ,  Paul Guiguizian ,  Howard Y. Bell ,  Alice Margaret Sophie Elliott ,  Patrick Minter Killough ,  Bernardus Maria Geertshuis ,  Herie Javier Soto

IPC: G01N21/39 ,  G01J3/42 ,  G01J3/433 ,  G01N21/27 ,  G01N21/31 ,  G01N21/552

CPC classification number: G01N21/39 ,  G01J3/42 ,  G01J3/433 ,  G01N21/274 ,  G01N21/552 ,  G01N2021/3129

Abstract: Disclosed is a spectroscopic device, system, and method for measuring the concentration of one or more molecular species of interest in a gas, liquid or solid sample, where the device may be portable, may be commercially manufactured, and/or may be adapted to existing systems and/or integrated with new systems to provide optical gas sensing for such systems. The disclosed devices, systems, and methods can be particularly useful in monitoring the purity of, e.g., a certain gas species, including determining whether a gas mixture contains certain gas species above a set concentration limit.

公开(公告)号：US20240094122A1

公开(公告)日：2024-03-21

申请号：US18370034

申请日：2023-09-19

Applicant: SICK AG

Inventor： Thomas BEYER ,  Julian EDLER

IPC: G01N21/39 ,  G01J3/433

CPC classification number: G01N21/39 ,  G01J3/4338 ,  G01N2201/121 ,  G01N2201/1273

Abstract: The invention relates to a method for measuring a concentration of a gas in a gas mixture, said method comprising that: a light beam modulated in a ramp shape and/or in a step shape in its wavelength and additionally periodically modulated, in particular in its wavelength, is transmitted from a light source, in particular a laser, into a measurement zone; the modulated light beam passes through a gas mixture in the measurement zone and is detected as reception light by a detector, wherein the reception light is converted by the detector into a detector signal; a derivative signal is determined based on the detector signal by performing a transformation of the detector signal into the frequency range, in particular by a Fourier transform of the detector signal, wherein an evaluation of the detector signal transformed into the frequency range is performed, in particular only, for an n-fold of the frequency of the modulated light beam in order to obtain the derivative signal; and at least two measurement values of a phase of the derivative signal are determined and a correction function is calculated based on the determined measurement values of the phase of the derivative signal in order to correct the derivative signal with the correction function.

公开(公告)号：US11913835B1

公开(公告)日：2024-02-27

申请号：US18353175

申请日：2023-07-17

Applicant: Vector Atomic, Inc.

Inventor： Micah Perry Ledbetter ,  Martin Machai Boyd ,  Andrew Vernon Dowd ,  William David Lunden ,  Jonathan David Roslund

IPC: G01J3/433

CPC classification number: G01J3/4338 ,  G01J2003/4332

Abstract: Embodiments herein describe spectroscopy systems that use an unmodulated reference optical signal to mitigate noise, or for other advantages. In one embodiment, the unmodulated reference optical signal is transmitted through the same vapor cell as a modulated pump optical signal. As such, the unmodulated reference optical signal experiences absorption by the vapor, which converts laser phase noise to amplitude noise like the other optical signals passing through the vapor cell. In one embodiment, the unmodulated reference optical signal has an optical path in the gas cell that is offset (or non-crossing) from the optical path of the modulated pump optical signal. The unmodulated reference optical signal allows removal or mitigation of the noise on the other optical signal.

公开(公告)号：US11796392B2

公开(公告)日：2023-10-24

申请号：US18063213

申请日：2022-12-08

Applicant: IRsweep AG

Inventor： Stéphane Schilt ,  Pierre Brochard ,  Kenichi Komagata ,  Giulio Terrasanta ,  Andreas Hugi

IPC: G01J3/433 ,  G01J3/10 ,  H01S5/40 ,  H01S5/062 ,  G01J3/42

CPC classification number: G01J3/433 ,  G01J3/10 ,  H01S5/0623 ,  H01S5/4006 ,  G01J2003/102 ,  G01J2003/423 ,  G01J2003/4332

Abstract: A dual-comb spectrometer comprising two lasers outputting respective frequency combs having a frequency offset between their intermode beat frequencies. One laser acts as a master and the other as a follower. Although the master laser is driven nominally with a DC drive signal, the current on its drive input line nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the driven master laser. This effect is exploited by tapping off this AC component and mixing it with a reference frequency to provide the required frequency offset, the mixed signal then being supplied to the follower laser as the AC component of its drive signal. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized.

公开(公告)号：US20230314266A1

公开(公告)日：2023-10-05

申请号：US18316486

申请日：2023-05-12

Applicant: Bridger Photonics, Inc.

Inventor： Aaron Thomas Kreitinger ,  Michael James Thorpe

IPC: G01M3/18 ,  G01J3/433 ,  G01N21/39 ,  G06V10/30

CPC classification number: G01M3/18 ,  G01J3/4338 ,  G01N21/39 ,  G06V10/30 ,  G01J2003/423

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for anomalous gas concentration detection. A spectroscopic system, such as a wavelength modulated spectroscopy (WMS) system may measure gas concentrations in a target area. However, noise, such as speckle noise, may interfere with measuring relatively low concentrations of gas, and may lead to false positives. A noise model, which includes a contribution from a speckle noise model, may be used to process data from the spectroscopic system. An adaptive threshold may be applied based on an expected amount of noise. A speckle filter may remove measurements which are outliers based on a measurement of their noise. Plume detection may be used to determine a presence of gas plumes. Each of these processing steps may be associated with a confidence, which may be used to determine an overall confidence in the processed measurements/gas plumes.

公开(公告)号：US11747204B2

公开(公告)日：2023-09-05

申请号：US17394143

申请日：2021-08-04

Applicant: The Johns Hopkins University

Inventor： Scott M. Hendrickson ,  Jeremiah J. Wathen ,  Michael J. Fitch ,  David W. Blodgett ,  Vincent R. Pagan

IPC: G01J3/433 ,  G02B3/04 ,  G01J3/02 ,  G01J3/28

CPC classification number: G01J3/4338 ,  G01J3/0208 ,  G01J3/0264 ,  G01J3/2823 ,  G02B3/04 ,  G01J2003/4332

Abstract: A system includes first and second radiation sources, first and second detectors, a signal digitizer, a controller, and an analyzer. The first and second radiation sources generate respective first and second beams of radiation to irradiate a target. The first beam and second beams each include a first wavelength operated at a first modulation frequency and a second wavelength operated at a second modulation frequency. The first and second detectors each include a photo-sensitive element that generate first or second detection signals, a Faraday shielding enclosure, a signal amplifier, and a frequency mixer to frequency-adjust the first or second detection signals. The controller provides timing information to inform an activation scheme of the first and second radiation sources and corresponding radiation detection events at the first and second detectors. The analyzer analyzes the first and second detection signals and determines at least amplitude and phase information of the scattered radiation.

公开(公告)号：US11733096B2

公开(公告)日：2023-08-22

申请号：US17352327

申请日：2021-06-20

Applicant: Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences

Inventor： Leiran Wang ,  Qibing Sun ,  Lei Shi ,  Wenfu Zhang

IPC: G01J3/433 ,  G01J3/02 ,  G01J3/10 ,  G02F1/35 ,  G02F1/355 ,  G01N21/3504 ,  G01J3/42

CPC classification number: G01J3/433 ,  G01J3/0229 ,  G01J3/108 ,  G01N21/3504 ,  G02F1/3536 ,  G02F1/3551 ,  G01J2003/423 ,  G01J2003/4334 ,  G02F2202/20 ,  G02F2203/11 ,  G02F2203/56

Abstract: An ultrahigh-resolution mid-infrared (MIR) dual-comb spectroscopy (DCS) measurement device includes a pump unit, a microring resonator (MRR) unit, a modulation unit, a splitting unit, a testing unit, a signal detection unit, a power balance unit, a reference detection unit and a spectral analysis unit. The measurement method includes: adjusting the laser emitted by the pump unit to the MRR unit; adjusting the modulation unit and performing dual-frequency modulation; generating two sets of MIR optical frequency combs (OFCs) with different repetition rates and splitting the MIR OFCs into the test light and the reference light; performing photoelectric conversion on the test light and injecting the test light to the spectral analysis unit; performing photoelectric conversion on the reference light and injecting the reference light to the spectral analysis unit; and performing Fourier transformation and data processing on test results to obtain absorption spectrum of the to-be-tested sample.

公开(公告)号：US11585749B2

公开(公告)日：2023-02-21

申请号：US17063483

申请日：2020-10-05

Applicant: Apple Inc.

Inventor： Miikka M. Kangas ,  Mark Alan Arbore ,  David I. Simon ,  Michael J. Bishop ,  James W. Hillendahl ,  Robert Chen

IPC: G01N21/27 ,  G01N21/35 ,  G01N21/47 ,  G01J3/32 ,  G01J3/36 ,  G01J3/433 ,  G01J3/447 ,  G01J3/02 ,  G01J3/42 ,  G01N21/49 ,  G01N21/21

Abstract: This relates to systems and methods for measuring a concentration and type of substance in a sample at a sampling interface. The systems can include a light source, optics, one or more modulators, a reference, a detector, and a controller. The systems and methods disclosed can be capable of accounting for drift originating from the light source, one or more optics, and the detector by sharing one or more components between different measurement light paths. Additionally, the systems can be capable of differentiating between different types of drift and eliminating erroneous measurements due to stray light with the placement of one or more modulators between the light source and the sample or reference. Furthermore, the systems can be capable of detecting the substance along various locations and depths within the sample by mapping a detector pixel and a microoptics to the location and depth in the sample.