Distributed fiber optic sensing systems (DFOS) methods, and structures that employ DVS / DAS point sensors and a two-stage processing methodology / structure that advantageously enable point sensors to send sensor data at any time - thereby providing significant processing advantages over the prior art.

The present disclosure relates to a passive fiber optic cabinet and a system for detecting a state of a door of a passive fiber optic cabinet. A passive fiber optic cabinet is provided, comprising: a housing; a door coupled to the housing and configured to be switchable between an open state and a closed state; a switch sensor module including a detection fiber Bragg grating (FBG) sensor and a stress applying mechanism corresponding to the detection FBG sensor, the stress applying mechanism configured to apply a stress o the detection FBG sensor, one of the detection FBG sensor and the stress applying mechanism being positioned at the door, and the other of the detection FBG sensor and the stress applying mechanism being positioned at the housing.

Provided are an image analysis method, an image analysis device, a program, and a recording medium capable of more easily eliminating an influence of an illuminance distribution in a case where an object is imaged.

The embodiment of the present invention acquires first image data obtained by imaging an object, which develops color according to an amount of external energy in a case where the external energy is applied, with a first sensitivity, acquires second image data obtained by imaging the object with a second sensitivity different from the first sensitivity, calculates a ratio of an image signal value indicated by the first image data with respect to an image signal value indicated by the second image data, and estimates the amount of the external energy applied to the object, based on a correspondence relationship between the amount of the external energy and the ratio, and a calculation result of the ratio in a calculation step.

Methods of improving the measurement of knee stress in an ion-exchanged chemically strengthened Li-containing glass sample that includes a knee are disclosed. One of the methods includes compensating for a shift in the location of the TIR-PR transition location associated with the critical angle location, wherein the shift is due to the presence of a leaky mode. Another method includes applying select criteria to the captured mode spectra image to ensure a high-quality image is used for the knee stress calculation. Another method combines direct and indirect measurements of the knee stress using the mode spectra from multiple samples to obtain greater accuracy and precision as compared to using either the direct measurement method or the indirect measurement method alone. Quality control methods of forming the glass samples using measured mode spectra and related techniques for ensuring an accurate measurement of the knee stress are also disclosed.

Methods of improving the measurement of knee stress in an ion-exchanged chemically strengthened Li-containing glass sample that includes a knee are disclosed. One of the methods includes compensating for a shift in the location of the TIR-PR transition location associated with the critical angle location, wherein the shift is due to the presence of a leaky mode. Another method includes applying select criteria to the captured mode spectra image to ensure a high-quality image is used for the knee stress calculation. Another method combines direct and indirect measurements of the knee stress using the mode spectra from multiple samples to obtain greater accuracy and precision as compared to using either the direct measurement method or the indirect measurement method alone. Quality control methods of forming the glass samples using measured mode spectra and related techniques for ensuring an accurate measurement of the knee stress are also disclosed.

A retrographic sensor includes a transparent structure, a transparent elastomeric pad, and an at least partially reflective layer. One or more light sources emit light into a side surface of the transparent structure. The light undergoes internal reflection in the transparent structure and is reflected toward a camera oriented toward the transparent structure. The at least partially reflective layer may be semi-specular in some embodiments.

A retrographic sensor includes a transparent structure, a transparent elastomeric pad, and an at least partially reflective layer. One or more light sources emit light into a side surface of the transparent structure. The light undergoes internal reflection in the transparent structure and is reflected toward a camera oriented toward the transparent structure. The at least partially reflective layer may be semi-specular in some embodiments.

A stress luminescence measurement method according to one aspect includes the steps of: placing a stress luminescent material on a surface of a sample; irradiating the stress luminescent material with excitation light; acquiring a first captured image by imaging the stress luminescent material during irradiation of the excitation light; applying a load to the sample; acquiring a stress luminescence image by imaging stress luminescence of the stress luminescent material; irradiating the stress luminescent material after removal of the load with the excitation light; acquiring a second captured image during irradiation of the excitation light by imaging the stress luminescent material in a state in which the load has been removed; and storing the first captured image and the second captured image in a memory in association with the stress luminescent image.

A stress luminescence measurement method according to one aspect includes the steps of: placing a stress luminescent material on a surface of a sample; irradiating the stress luminescent material with excitation light; acquiring a first captured image by imaging the stress luminescent material during irradiation of the excitation light; applying a load to the sample; acquiring a stress luminescence image by imaging stress luminescence of the stress luminescent material; irradiating the stress luminescent material after removal of the load with the excitation light; acquiring a second captured image during irradiation of the excitation light by imaging the stress luminescent material in a state in which the load has been removed; and storing the first captured image and the second captured image in a memory in association with the stress luminescent image.

The present invention discloses a two-dimensional optical waveguide pressure sensor array comprising two or more row optical waveguides; two or more column optical waveguides, wherein the row optical waveguides and the column optical waveguides are deformable and arranged in a planar array to define a sensor in the crosspoints, wherein each crosspoint includes one of the row waveguides in contact with one of the column waveguides at its intersection point; wherein each crosspoint further includes a light coupling structure configured to enhance waveguide bending when pressure is applied to the crosspoint; wherein the light coupling structure comprises a layer of mechanical light scattering material disposed in contact with at least one of the row or column optical waveguide; or wherein the optical waveguide pressure sensor array can sense pressure by providing light to the row optical waveguides and measuring light coupled at each crosspoint to its column optical waveguide.