Optical oil component sensor and sensing method using the same

An optical oil component sensing method comprising:

• receiving, by a reference optical waveguide and a sensing optical waveguide, light emitted from a light source unit, wherein a sensing portion of the sensing optical wave guide is in contact with a test target oil;
• guiding the light into the reference optical waveguide and the sensing optical waveguide;
• receiving, by a light-receiving unit, both a reference light signal output from the reference optical waveguide and a test light signal output from the sensing optical waveguide;
• and
• identifying, by a control unit, components of the test target oil by comparing optical properties of the reference light signal and the test light signal with each other,
• wherein an outer surface of the reference optical waveguide is completely covered with a single clad,
• a trench part is formed in the single clad around an outer surface of the sensing portion of the sensing optical waveguide, the trench part storing the test target oil therein, and
• the reference optical waveguide the sensing optical waveguide and the trench part are formed in the single clad.

An optical oil component sensor comprising:

• a light source unit;
• a single clad;
• a reference optical waveguide core formed in and completely covered by the single clad and configured to guide light thereinto, for receiving and outputting light emitted from the light source unit;
• a sensing optical waveguide core formed in the single clad and configured to guide light thereinto for receiving and outputting the light emitted from the light source unit such that a sensing portion of the sensing optical waveguide core is continuous and includes an outer surface in contact with a test target oil;
• a trench part formed in the single clad around the outer surface of the sensing portion of the sensing optical waveguide core, the trench part storing the test target oil therein;
• a light-receiving unit for receiving both a reference light signal, output from the reference optical waveguide core, and a test light signal, output from the sensing optical waveguide core;
• and
• a control unit for identifying components of the test target oil by comparing optical properties of the reference light signal and the test light signal with each other.