Back to results
US 9,778,110 B1Granted
Self-referencing cavity enhanced spectroscopy (SRCES) systems and methods
AssigneePicarro, Inc.
InventorsChris W. Rella, Sze M. Tan, Yonggang He
Life of this patent
Estimating the term…
Abstract
Described self-referencing cavity enhanced spectroscopy (SRCES) systems and methods are tailored to acquiring spectra in a middle regime, in which signals are lower than optimal for conventional absorption spectroscopy, and absorption is higher than optimal for cavity ring-down spectroscopy (CRDS). Longitudinal mode resonance spectral peaks are analyzed individually to extract intensity ratios (e.g. maximum to minimum) and/or curve-fitting parameters, obviating the need to measure or precisely control the input light intensity.
Claims39
A spectroscopy apparatus comprising:
- a resonant optical cavity configured to hold a sample;
- an optical detector configured to detect optical signals emitted from the optical cavity and generate electrical signals from the optical signals, the optical signals defining a plurality of intensity values characterizing a response of the sample to light in the optical cavity as a frequency of the light is scanned over a range of frequencies spanning a plurality of longitudinal mode resonance spectral peaks;
- and
- a processor electrically connected to the optical detector and configured to determine, from the electrical signals, a sample absorption coefficient by fitting at least two intensity values characterizing a longitudinal mode resonance spectral peak to a model of the longitudinal mode resonance spectral peak, wherein the at least two intensity values comprise a maximum intensity and a minimum intensity characterizing the longitudinal mode resonance spectral peak, and wherein the processor is configured to perform at least one of:
- i. determining the maximum intensity characterizing the longitudinal mode resonance spectral peak by averaging a maximum intensity of the longitudinal mode resonance spectral peak and a maximum intensity of an immediately neighboring longitudinal mode resonance spectral peak, and
- ii. determining the minimum intensity characterizing the longitudinal mode resonance spectral peak by averaging a minimum intensity of the longitudinal mode resonance spectral peak and a minimum intensity of an immediately neighboring longitudinal mode resonance spectral peak.
3 more elements
A non-transitory computer-readable medium storing instructions which, when executed by a hardware processor, cause the processor to:
- receive electrical signals generated from optical signals emitted from a resonant optical cavity configured to hold a sample, the optical signals characterizing a response of the sample to light in the optical cavity as a frequency of the light is scanned over a range of frequencies spanning a plurality of longitudinal mode resonance spectral peaks;
- and
- determine, from the electrical signals, a sample absorption coefficient by fitting at least two intensity values characterizing a longitudinal mode resonance spectral peak to a model of the longitudinal mode resonance spectral peak, wherein the at least two intensity values comprise a maximum intensity and a minimum intensity characterizing the longitudinal mode resonance spectral peak, and wherein the instructions further cause the processor to perform at least one of:
- i. determining the maximum intensity characterizing the longitudinal mode resonance spectral peak by averaging a maximum intensity of the longitudinal mode resonance spectral peak and a maximum intensity of an immediately neighboring longitudinal mode resonance spectral peak, and
- ii. determining the minimum intensity characterizing the longitudinal mode resonance spectral peak by averaging a minimum intensity of the longitudinal mode resonance spectral peak and a minimum intensity of an immediately neighboring longitudinal mode resonance spectral peak.
2 more elements
A computer system comprising a hardware processor and associated memory configured to:
- receive electrical signals generated from optical signals emitted from a resonant optical cavity configured to hold a sample, the optical signals characterizing a response of the sample to light in the optical cavity as a frequency of the light is scanned over a range of frequencies spanning a plurality of longitudinal mode resonance spectral peaks;
- and
- determine, from the electrical signals, a sample absorption coefficient by fitting at least two intensity values characterizing a longitudinal mode resonance spectral peak to a model of the longitudinal mode resonance spectral peak, wherein the at least two intensity values comprise a maximum intensity and a minimum intensity characterizing the longitudinal mode resonance spectral peak, and wherein the processor is configured to perform at least one of:
- i. determining the maximum intensity characterizing the longitudinal mode resonance spectral peak by averaging a maximum intensity of the longitudinal mode resonance spectral peak and a maximum intensity of an immediately neighboring longitudinal mode resonance spectral peak, and
- ii. determining the minimum intensity characterizing the longitudinal mode resonance spectral peak by averaging a minimum intensity of the longitudinal mode resonance spectral peak and a minimum intensity of an immediately neighboring longitudinal mode resonance spectral peak.
2 more elements
A method comprising:
- receiving electrical signals generated from optical signals emitted from a resonant optical cavity configured to hold a sample, the optical signals characterizing a response of the sample to light in the optical cavity as a frequency of the light is scanned over a range of frequencies spanning a plurality of longitudinal mode resonance spectral peaks;
- and
- determining, from the electrical signals and using a hardware processor, a sample absorption coefficient by fitting at least two intensity values characterizing a longitudinal mode resonance spectral peak to a model of the longitudinal mode resonance spectral peak, wherein the at least two intensity values comprise a maximum intensity and a minimum intensity characterizing the longitudinal mode resonance spectral peak, and wherein the processor is configured to perform at least one of:
- i. determining the maximum intensity characterizing the longitudinal mode resonance spectral peak by averaging a maximum intensity of the longitudinal mode resonance spectral peak and a maximum intensity of an immediately neighboring longitudinal mode resonance spectral peak, and
- ii. determining the minimum intensity characterizing the longitudinal mode resonance spectral peak by averaging a minimum intensity of the longitudinal mode resonance spectral peak and a minimum intensity of an immediately neighboring longitudinal mode resonance spectral peak.
2 more elements
Dependencies are inferred from the claim text.