High Sensitivity Surface Plasmon Resonance Sensor Based on a Ge-Doped Defect and D-Shaped Microstructured Optical Fiber

In this work a plasmonic sensor with a D-Shaped microstructured optical fiber [Formula: see text] is proposed to detect a wide range of analyte refractive index [Formula: see text] by doping the pure silica [Formula: see text] core with distinct concentrations of Germanium Dioxide [Formula: see text] , causing the presentation of high spectral sensitivity. In this case, the fiber is shaped by polishing a coating of [Formula: see text] , on the region that will be doped with [Formula: see text] , in the polished area, a thin gold [Formula: see text] layer, which constitutes the plasmonic material, is introduced, followed by the analyte, in a way which the gold layer is deposited between the [Formula: see text]. 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 [Formula: see text] , with a limit operation where [Formula: see text] varies from 1.32 to 1.45. Within this application, the sensor has reached an average wavelength sensitivity [Formula: see text] of up to [Formula: see text]. With this level of sensitivity, the D-Shaped format and wide range of [Formula: see text] detection, the proposed fiber has great potential for sensing applications in several areas.