Patent ID: 11947159
Assignee: HONEYWELL INTERNATIONAL INC.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. A method of determining a rate of rotation around a winding axis of a fibre coil comprising a hollow core optical fibre, the method comprising:
propagating a clockwise optical signal, which is linearly polarized, in the hollow core optical fibre and in a clockwise direction around the winding axis;
propagating a counterclockwise optical signal, which is linearly polarized, in the hollow core optical fibre and in a counterclockwise direction around the winding axis, wherein the clockwise optical signal and the counterclockwise optical signal have a differential phase proportional to the rate of rotation of the fibre coil around the winding axis, wherein the hollow core optical fibre comprises (a) a tubular outer jacket comprising an inner surface, (b) a hollow core, and (c) a cladding, wherein the cladding comprises a plurality of glass cladding capillaries, wherein the hollow core is bounded by inwardly facing portions of outer surfaces of the plurality of glass cladding capillaries, wherein the plurality of glass cladding capillaries are arranged around the hollow core, wherein each glass cladding capillary is bonded to the inner surface of the tubular outer jacket, and wherein the hollow core optical fibre has a holding parameter value of less than 1×10−5 m−1, or less than 1×10−6 m−1, or in a range of 1×10−6 m−1 to 1×10−5 m−1, or in a range of 1×10−7 m−1 to 1×10−6 m−1, or in a range of 1×10−7 m−1 to 1×10−5 m−1; and
determining the rate of rotation around the winding axis of the fibre coil based upon the differential phase of the counterclockwise optical signal and the clockwise optical signal.