Optical fiber sensors
AssigneeWorcester Polytechnic Institute
InventorsYuxiang Liu, Pratap Rao, Yundong Ren, Mucheng Li
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Abstract
A fiber optic sensing device includes an optical fiber having a polished end defining a flat sensory portion coated with a lossy-mode-resonance (LMR) coating. A reflective coating on an end face of the optical fiber facilitates propagation of a return signal. An optic circuit for identifies a wavelength attenuated by the LMR coating from the return signal reflected by the reflective coating based on a moisture presence at the sensory portion. Various gaseous parameters may be detected based on the coating on the sensory portion. An LMR coating of tin oxide (SnO2) is employed for moisture sensing.
Claims20
An optical fiber sensor device, comprising:
- an optical fiber having a proximate end and a distal end;
- a sensory region formed at the distal end, the sensory region defined by an asymmetric cross section and having an annular surface and a flat surface;
- and
- a sensory coating disposed on the flat surface, the sensory coating responsive to a gaseous presence for returning a signal having a wavelength based on the gaseous presence.
A method of detecting moisture in an industrially sensitive environment, comprising:
- polishing an optical fiber for forming a recession in an annular, outer surface to form a sensory region defined by a flat surface;
- severing the optical fiber along the flat surface to form an end face perpendicular to an axis of the optical fiber;
- applying a sensory coating to the flat surface to form a sensory region responsive to a gaseous presence;
- and
- receiving a return signal through the optical fiber based on an absorption of wavelengths of light by the sensory coating.
A fiber optical sensing device comprising:
- an optical fiber having a polished end defining a flat sensory portion coated with a lossy-mode-resonance (LMR) coating;
- a reflective coating on an end face of the optical fiber;
- and
- an optical circuit for identifying a wavelength attenuated by the LMR coating from a return signal reflected by the reflective coating based on a moisture presence at the sensory portion.
Dependencies are inferred from the claim text.