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US 11,448,593 B1Granted
Method of spectroscopically characterizing a surface
AssigneeInsight Photonic Solutions, Inc.
InventorsJason Ensher, Christopher Wood
Life of this patent
Estimating the term…
Abstract
A device and method for performing reflectivity measurements at a distance by receiving two or more reflected signals (using two or more different wavelength sweeps) and calculating ratios of the two (or more) received reflected signals, for the purpose of determining the composition of a material or surface at a distance.
Claims26
A method for performing measurements at a distance of returning electromagnetic radiation using a device including an electromagnetic radiation source and a photodetector, the method comprising:
- using the electromagnetic radiation source, generating a first sweep in time of electromagnetic radiation within a first range of wavelengths, wherein the first sweep comprises multiple different wavelengths of electromagnetic radiation emitted at different times;
- emitting a portion of the electromagnetic radiation of the first sweep to interact with an object;
- receiving a returning portion of the emitted portion of the first sweep that interacted with the object;
- combining through interference the returning portion of the emitted portion of the first sweep with a reference portion of the first sweep;
- detecting with the photodetector the combined electromagnetic radiation of the first sweep;
- outputting a first signal by the photodetector based on the detected combined electromagnetic radiation;
- using the electromagnetic radiation source, generating a second sweep in time of electromagnetic radiation within a second range of wavelengths, wherein the second sweep comprises multiple different wavelengths of electromagnetic radiation emitted at different times;
- emitting a portion of the electromagnetic radiation of the second sweep to interact with the object;
- receiving a returning portion of the emitted portion of the second sweep that interacted with the object;
- combining through interference the returning portion of the emitted portion of the second sweep with a reference portion of the second sweep;
- detecting with the photodetector the combined electromagnetic radiation of the second sweep;
- outputting a second signal by the photodetector based on the detected combined electromagnetic radiation;
- and
- determining using circuitry a reflectivity of the object based on a ratio of the first signal and the second signal, wherein a signal returned from the object depends on a wavelength of incident electromagnetic radiation.
11 more elements
A method for performing measurements at a distance of returning electromagnetic radiation using a device including an electromagnetic radiation source and a photodetector, the method comprising:
- using the electromagnetic radiation source, generating a first sweep in time of electromagnetic radiation within a first range of wavelengths, wherein the first sweep comprises multiple different wavelengths of electromagnetic radiation emitted at different times;
- emitting a portion of the electromagnetic radiation of the first sweep to interact with an object;
- receiving a returning portion of the emitted portion of the first sweep that interacted with the object;
- combining through interference the returning portion of the emitted portion of the first sweep with a reference portion of the first sweep;
- detecting with the photodetector the combined electromagnetic radiation of the first sweep;
- and
- outputting a first signal by the photodetector based on the detected combined electromagnetic radiation
- wherein the combined electromagnetic radiation includes:
- a positive signal from the returning portion of the first sweep that interacted with the object;
- and
- a noise signal caused by:
- common-mode noise present in both the emitted portion of the first sweep and the reference portion of the first sweep;
- and
- common-mode signal received with the returning portion of the first sweep;
- and
- further comprising removing the noise signal from the combined electromagnetic radiation using balanced photodetection.
13 more elements
An optical device for performing measurements at a distance of returning electromagnetic radiation, the optical device comprising:
- an electromagnetic radiation source configured to generate a first sweep in time of electromagnetic radiation within a first range of wavelengths, wherein the first sweep comprises multiple different wavelengths of electromagnetic radiation emitted at different times;
- a lens system configured to:
- emit a portion of the first sweep to interact with an object;
- and
- receive a returning portion of the emitted first sweep that interacted with the object;
- an interferometer configured to combine through interference the received returning portion of the first sweep with a reference portion of the first sweep;
- and
- a photodetector configured to:
- detect the combined electromagnetic radiation of the first sweep;
- and
- output a signal based on the detected combined electromagnetic radiation;
- wherein the electromagnetic radiation source is further configured to generate a second sweep in time of electromagnetic radiation within a second range of wavelengths;
- wherein the second sweep comprises multiple different wavelengths of electromagnetic radiation emitted at different times;
- wherein the lens system is further configured to:
- emit a portion of the second sweep to interact with the object;
- and
- receive a returning portion of the emitted second sweep that interacted with the object;
- wherein the interferometer further configured to combine through interference the received returning portion of the second sweep with a reference portion of the second sweep;
- the photodetector is further configured to:
- detect the combined electromagnetic radiation of the second sweep;
- and
- output a second signal based on the detected combined electromagnetic radiation
- further comprising circuitry configured to determine a reflectivity of the object based on a ratio of the first signal and the second signal, wherein a signal returning from the object depends on a wavelength of incident electromagnetic radiation.
20 more elements
An optical device for performing measurements at a distance of returning electromagnetic radiation, the optical device comprising:
- an electromagnetic radiation source configured to generate a first sweep in time of electromagnetic radiation within a first range of wavelengths, wherein the first sweep comprises multiple different wavelengths of electromagnetic radiation emitted at different times;
- a lens system configured to:
- emit a portion of the first sweep to interact with an object;
- and
- receive a returning portion of the emitted first sweep that interacted with the object;
- an interferometer configured to combine through interference the received returning portion of the first sweep with a reference portion of the first sweep, and
- a photodetector configured to:
- detect the combined electromagnetic radiation of the first sweep;
- and
- output a signal based on the detected combined electromagnetic radiation;
- wherein the combined electromagnetic radiation includes:
- a positive signal from the returning portion of the first sweep that interacted with the object;
- and
- a noise signal caused by:
- common-mode noise present in both the emitted portion of the first sweep and the reference portion of the first sweep;
- and
- common-mode signal received with the returning portion of the first sweep;
- and
- wherein the photodetector comprises a balanced photodetector and is configured to remove the noise signal from the combined electromagnetic radiation using balanced photodetection.
16 more elements
Dependencies are inferred from the claim text.