Method of making hinged self-referencing Fabry–Pérot cavity sensors [U.S. Patent US11287575B2]
U.S. Patent US11287575B2
Abstract
A method is provided for fabricating a passive optical sensor on a tip of an optical fiber. The method includes perpendicularly cleaving a tip of an optical fiber and mounting the tip of the optical fiber in a specimen holder of a photosensitive polymer three-dimensional micromachining machine. The method includes forming a three-dimensional microscopic optical structure within the photosensitive polymer that comprises a two cavity Fabry-Perot Interferometer (FPI) having a hinged optical layer that is pivotally coupled to a suspended structure. The method includes removing an uncured portion of the photosensitive polymer using a solvent. The method includes depositing a reflective layer on a mirror surface of the hinged optical layer. The method includes positioning the pivotally hinged optical layer to a closed position with the suspended structure, aligning the mirror surface with the cleaved tip of the optical fiber.