A method for determining the refractive index profile of a preform when the RIP is not substantially step-index like. (a) The preform deflection function is measured and transformed into a measured RIP. (b) A RI level and radius are assumed for the preform layer being evaluated and a compensation level RIP is calculated. (c) A theoretical deflection function is generated corresponding to the assumed RI level and radius and the generated data are transformed into a fitting RIP. (d) The fitting RIP is compared to the measured RIP and the comparison is evaluated against a predetermined accuracy level for the preform layer being evaluated. (e) Steps (b) and (c) are repeated iteratively until the predetermined accuracy level has been achieved. Steps (b) through (e) are repeated for each preform layer that needs to be compensated. Finally, a measurement artifact compensated refractive index profile is calculated for the preform.

An optical fiber preform including a glass material and a refractive index adjusting additive is disclosed. This preform has striae due to difference in concentration of the additive and the striae have concentric refractive index periodicity in at least a part thereof from a radial center of the preform to an outer periphery thereof. The respective striae pitches each indicating a period of the refractive index periodicity increase from the center of the preform to the outer periphery thereof.

A method of measuring a diameter of a core portion of an optical fiber preform including the core portion having a relatively high refractive index and a clad portion having a relatively low refractive index. The method includes applying parallel light to the optical fiber preform, and measuring the diameter of the core portion from an image captured by receiving the light having transmitted through the optical fiber preform.

Photonic errors in a photonic integrated circuit can be imaged using an on-chip light source integrated in a photonic layer of the circuit. The on-chip light source can generate light at wavelengths that propagates through one or more substrate layers to an image sensor sensitive to the wavelength range. The on-chip light source can be tunable and provide different power settings that can be utilized to detect different types of optical errors in the photonic integrated circuit.

Examples disclosed herein illustrate systems and methods to determine and evaluate the quality of mechanical splices of optical fibers using insertion loss estimation. In at least some of the disclosed systems and methods, an optical fiber termination system may include a reference fiber coupling a light source and a stub fiber of a fiber optic connector, a digital camera sensor and lens to capture images of scattered light emanating from a portion of the fiber optic connector and a portion of the reference fiber both in a field of view (FOV) of the digital camera sensor, and a processor. The processor may analyze digital images of scatter light emitted from at least a portion of the fiber optic connector and the reference fiber to estimate insertion loss at the fiber optic connector.

A system and method for measuring refractive index inhomogeneity between plates of a Lightguide Optical Element (LOE) uses an innovative measuring technique based on a shearing interferometric technique conventionally used to observe interference and test the collimation of light beams. Another feature of the current implementation is an innovative method for analyzing the characteristics of the generated interferogram to characterize discrepancies between adjacent plates in an LOE.

A method for estimating an orientation around a central axis of an optical fiber includes radiating light from a light source toward a side surface of the optical fiber, capturing an image of the side surface of the optical fiber by receiving the light transmitted through the optical fiber at a plurality of pixels disposed along a direction intersecting the central axis of the optical fiber, generating a luminance profile for the optical fiber based on a luminance value of light received by the plurality of pixels, and estimating an orientation around the central axis of the optical fiber using the luminance profile.

An optical fiber includes an integrated detector in the form of phosphors that emit light of a characteristic frequency or wavelength in response to leakage, through the fiber cladding, of light having an interrogation wavelength 1. Stimulation of phosphor emission by the interrogation light is indicative of aging or wear on the layers surrounding the cladding, and therefore can be used to assess the risk of imminent breakage of the fiber.

Disclosed herein are methods, structures, and devices for wafer scale testing of photonic integrated circuits.

Devices, systems, and methods for flexible, deployable structures with optical fiber are provided in accordance with various embodiments. For example, some embodiments include a system that may include a flexible, deployable structure and one or more optical fibers coupled with the flexible, deployable structure. In some embodiments, one or more conditions of the one or more optical fibers coupled with a flexible, deployable structure may be determined. One or more conditions of the flexible, deployable structure may be determined utilizing the determined one or more conditions of the one or more optical fibers coupled with the flexible, deployable structure. The one or more conditions of the one or more optical fibers may be correlated to the one or more conditions of the flexible, deployable structure.