Fiber-optic extensometer
AssigneePolytechnic Institute of New York University
InventorsNikhil Gupta, Nguyen Quang Nguyen
Life of this patent
Estimating the term…
Abstract
An extensometer having a loop of a single-mode optical fiber. At least two points of the loop are attached to desired locations on a specimen. Light is transmitted through the loop and the transmitted optical power is measured by a photodetector. The deformation of the specimen causes the size and shape of the loop to change, which changes the transmitted optical power. The change in optical power is related to extension or compression using calibration curves. The sensor works on the principle of transmitted power modulation through the curved section.
Claims19
A fiber-optic extensometer comprising:
- a) a loop of a single-mode optical fiber;
- b) a light source attached to a first end of the loop for transmitting light having an optical power through the loop;
- and
- c) a photodetector attached to a second end of the loop for detecting light transmitted through the loop,
- wherein light from the light source is transmitted through the loop, and the optical power of the light transmitted through the loop is measured by the photodetector, and
- wherein the loop has a radius smaller than a critical radius to provide measurable power losses.
A system for measuring the deformation of a specimen comprising:
- a) a fiber-optic extensometer comprising
- i) a loop of a single-mode optical fiber;
- ii) a light source attached to a first end of the loop for transmitting light through the loop;
- and
- iii) a photodetector attached to a second end of the loop for detecting light having an optical power transmitted through the loop,
- wherein light from the light source is transmitted through the loop, and the quantity of the light transmitted through the loop is measured by the photodetector;
- b) a computer having a database of calibration curves relating the change in the optical power of the light transmitted through the loop to the deformation of the loop;
- and
- c) causing the deformation of the specimen,
- whereby the deformation of the loop changes the optical power of the light being transmitted through the loop and the change in the optical power of the light being transmitted through the loop while the loop is undergoing the deformation is related to the amount of the deformation of the loop using the calibration curves.
A fiber-optic extensometer comprising:
- a) a loop of a single-mode optical fiber;
- b) a light source attached to a first end of the loop for transmitting light having an optical power through the loop;
- c) a photodetector attached to a second end of the loop for detecting light transmitted through the loop;
- and
- d) a database of calibration curves relating a change in the optical power of the light transmitted through the loop to deformation of the loop,
- wherein light from the light source is transmitted through the loop, and the optical power of the light transmitted through the loop is measured by the photodetector.
Dependencies are inferred from the claim text.