Methods of measuring thermal properties, and related apparatuses

Patent metadata

Field	Value
Publication number	US-12584803-B2
Application number	US-202318489706-A
Country	US
Kind code	B2
Filing date	Oct 18, 2023
Priority date	Oct 18, 2022
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

Embodiments disclosed herein relate to measuring thermal properties. At least one embodiment includes a method including heating a location of an object with an excitation laser beam, the excitation laser beam being a continuous-wave laser beam modulated by a square-wave modulation waveform. The method may also include measuring temperature at the location over time by measuring changes in one or more reflective properties at the location. Related apparatuses are also disclosed.

First claim

What is claimed is:

1 . A method comprising:
heating a location of an object with an excitation laser beam, the excitation laser beam being a continuous-wave laser beam modulated by a square-wave modulation waveform; and measuring temperature at the location over time by measuring changes in one or more reflective properties at the location.

2 . The method of claim 1 , wherein measuring changes in the one or more reflective properties at the location comprises impinging the location with a probe laser beam and measuring light reflected from the location.

3 . The method of claim 2 , wherein measuring light reflected from the location comprises filtering light reflected from the location to measure light from the probe laser beam reflected from the location.

4 . The method of claim 1 , further comprising impinging the location with a probe laser beam, wherein the excitation laser beam and the probe laser beam arrive at the location along a same path.

5 . The method of claim 1 , further comprising:
receiving the excitation laser beam and a probe laser beam from a single fiber-optic cable; and impinging the location with the probe laser beam.

6 . The method of claim 1 , further comprising generating a thermal profile of the object indicative of temperature of the location over time as the location is heated by the excitation laser beam and as the location cools after being heated by the excitation laser beam.

7 . The method of claim 6 , further comprising characterizing the location of the object based on the thermal profile.

8 . The method of claim 1 , further comprising, while heating the location, illuminating the object and capturing light reflected from the object at an imaging system.

9 . The method of claim 8 , wherein capturing the light reflected from the location comprises separating reflected probe light along a path from reflected illuminating light along the path.

10 . An apparatus comprising:
a first beam splitter in a first optical path toward an object, the first beam splitter configured to reflect a portion of an excitation laser beam and a portion of a probe laser beam along the first optical path toward the object, the first beam splitter in a second optical path between the object and a detector, the first beam splitter configured to transmit at least a portion of a reflected excitation laser beam, reflected from the object, and at least a portion of a reflected probe laser beam, reflected from the object, along the second optical path; and an optical filter in the second optical path, the optical filter configured to transmit the reflected probe laser beam along the second optical path toward the detector and to not transmit the reflected excitation laser beam along the second path.

11 . The apparatus of claim 10 , further comprising:
a second beam splitter in a third optical path between an illumination source and the object, the second beam splitter configured to redirect an illumination beam along the third optical path toward the optical filter, the optical filter configured to redirect the illumination beam along the third optical path toward the first beam splitter; the first beam splitter configured to transmit at least a portion of the illumination beam toward the object, the first beam splitter in a fourth optical path between the object and an imaging system, the first beam splitter configured to transmit at least a portion of a reflected illumination beam, reflected from the object, along the fourth optical path toward the optical filter; the optical filter configured to redirect the reflected illumination beam along the fourth path toward the second beam splitter; and the second beam splitter configured to transmit at least a portion of the reflected illumination beam along the fourth path toward the imaging system.

12 . The apparatus of claim 11 , further comprising an illumination source configured to provide the illumination beam along the third optical path.

13 . The apparatus of claim 11 , further comprising one or more lenses in the fourth optical path between the second beam splitter and the imaging system, the one or more lenses configured to focus the reflected illumination beam for the imaging system.

14 . The apparatus of claim 11 , wherein each of the first optical path, the second optical path, the third optical path, and the fourth optical path is a free-space optical path.

15 . The apparatus of claim 10 , further comprising a collimator configured to receive the excitation laser beam and the probe laser beam from a fiber-optic cable and direct the excitation laser beam and the probe laser beam along the first optical path between the collimator and the object.

16 . The apparatus of claim 10 , further comprising a microscope objective in the first optical path between the first beam splitter and the object, the microscope objective configured to focus the excitation laser beam and the probe laser beam onto the object.

17 . The apparatus of claim 10 , where the optical filter comprises a first optical filter, the apparatus further comprising a second optical filter in the second optical path between the first optical filter and the detector, the second optical filter configured to filter the reflected probe laser beam.

18 . The apparatus of claim 10 , further comprising the detector configured to receive the reflected probe laser beam.

19 . The apparatus of claim 10 , further comprising an imaging system comprising a charge-coupled device image sensor.

20 . A method comprising:
heating a location of an object with an excitation laser beam modulated with a periodic waveform at a single frequency; measuring changes in reflective properties at the location of the object; and determining thermal properties at the location based on a known or assumed heat capacity of a material of the object.

Assignees

• Battelle Energy Alliance Llc

Inventors

• Dennett Cody A
• Schley Robert S
• Wang Yuzhou
• Hurley David H
• Beausoleil Geoffrey L
• Murray Daniel J
• Moorehead Michael J

Classifications

• G01S7/4811

  common to transmitter and receiver · CPC title

• G01S7/4818

  using optical fibres · CPC title

• G01K11/125 Primary

  using changes in reflectance · CPC title