| Summary: | In this work a plasmonic sensor with a D-Shaped microstructured optical fiber <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><mi>MOF</mi></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> is proposed to detect a wide range of analyte refractive index <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><mrow><mi>RI</mi><mo> </mo></mrow><mo>;</mo><msub><mi mathvariant="normal">n</mi><mi mathvariant="normal">a</mi></msub></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> by doping the pure silica <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><msub><mrow><mi>SiO</mi></mrow><mn>2</mn></msub></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> core with distinct concentrations of Germanium Dioxide <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><msub><mrow><mi>GeO</mi></mrow><mn>2</mn></msub></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, causing the presentation of high spectral sensitivity. In this case, the fiber is shaped by polishing a coating of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>SiO</mi></mrow><mn>2</mn></msub></mrow></semantics></math></inline-formula>, on the region that will be doped with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>GeO</mi></mrow><mn>2</mn></msub></mrow></semantics></math></inline-formula>, in the polished area, a thin gold <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><mi>Au</mi></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> layer, which constitutes the plasmonic material, is introduced, followed by the analyte, in a way which the gold layer is deposited between the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>SiO</mi></mrow><mn>2</mn></msub></mrow></semantics></math></inline-formula>. and the analyte. The numerical results obtained in the study shows that the sensor can determine efficiently a range of 0.13 refractive index units <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><mi>RIU</mi></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, with a limit operation where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">n</mi><mi mathvariant="normal">a</mi></msub></mrow></semantics></math></inline-formula> varies from 1.32 to 1.45. Within this application, the sensor has reached an average wavelength sensitivity <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><mi>WS</mi></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> of up to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>11</mn><mo>,</mo><mn>650.63</mn><mrow><mo> </mo><mi>nm</mi></mrow><mo>/</mo><mi>RIU</mi></mrow></semantics></math></inline-formula>. With this level of sensitivity, the D-Shaped format and wide range of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="normal">n</mi><mi mathvariant="normal">a</mi></msub></mrow></semantics></math></inline-formula> detection, the proposed fiber has great potential for sensing applications in several areas.
|
|---|