US3978713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser generation of ultrasonic waves for nondestructive testing
Assignee: General Electric Co
•
Filing: 1975-05-27
•
Granted: 1976-09-07
•
Expires: 1995-05-27
Abstract
Abstract An object is tested for thickness or for presence and location of flaws by impacting a pulsed laser beam on the surface of the object so as to generate ultrasonic waves by rapid heating of a thin surface layer thereon. The reflected ultrasonic echo in the object is detected by monitoring surface motion with a rough surface interferometer.
Inventors
- 👤 Carl M. Penney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:25
CPC Classifications
G; G10; G10K; G10K15/00; G10K15/04; G10K15/046; G01; G01N; G01N29/00; G01N29/22; G01N29/24; G01N29/2418; G01N2291/00; G01N2291/04; G01N2291/042; G01N2291/0423
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
In apparatus for nondestructively testing a medium by generating pulses of ultrasonic energy within said medium and measuring the response of said medium to said pulses, the improvement wherein at least a portion of said medium comprises a surface absorbent to optical energy and having a characteristic damage threshold for deleterious surface damage, and further including means for directing an intense pulse of optical energy below said damage threshold onto the absorbent portion of said medium to generate said pulses of ultrasonic energy within said medium.
Claim 2
Dependent Claim
86 words
In apparatus for nondestructively testing a medium by generating pulses of ultrasonic energy within said medium and measuring the response of said medium to said pulses, the improvement wherein at least a portion of said medium comprises a surface absorbent to optical energy and having a characteristic damage threshold for deleterious surface damage, and further including means for directing an intense pulse of optical energy below said damage threshold onto the absorbent portion of said medium to generate said pulses of ultrasonic energy within said medium.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein said means for directing an intense pulse of optical energy onto said medium comprises a pulsed laser.
Claim 4
Dependent Claim
30 words
The apparatus of claim 2 wherein said pulsed laser is repetitively pulsed at a desired acoustic frequency to concentrate the generated pulses of ultrasonic energy in a narrow frequency band.
Claim 5
Dependent Claim
47 words
Apparatus for nondestructively testing a solid medium, comprising: means for directing an intense pulse of coherent optical energy onto said medium to generate acoustic waves therein; and optical means responsive to movement of the surface of said medium for detecting an acoustic pulse echo in the medium.
Claim 6
Dependent Claim
47 words
Apparatus for nondestructively testing a solid medium, comprising: means for directing an intense pulse of coherent optical energy onto said medium to generate acoustic waves therein; and optical means responsive to movement of the surface of said medium for detecting an acoustic pulse echo in the medium.
Claim 7
Dependent Claim
15 words
The apparatus of claim 4 wherein said coherent optical energy is in the near-ultraviolet range.
Claim 8
Dependent Claim
24 words
The apparatus of claim 4 wherein said means for directing an intense pulse of coherent optical energy onto said medium comprises a pulsed laser.
Claim 9
Dependent Claim
28 words
The apparatus of claim 6 wherein said pulsed laser is repetitively pulsed at a desired acoustic frequency to concentrate the generated acoustic waves in a narrow frequency band.
Claim 10
Dependent Claim
23 words
The apparatus of claim 4 wherein said optical means responsive to movement of the surface of said medium comprises rough surface interferometer means.
References Cited (Backward Citations)
US3782177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |