Surface plasmon resonance sensors based on uniform-waist tapered fibers in a reflective configuration.
We present a configuration for surface plasmon resonance sensors based on uniform-waist tapered optical fibers and reflective elements. Once the fiber is tapered fulfilling the adiabatic criterion, a multilayer including a metallic medium is asymmetrically deposited on the uniform waist of the fiber. This feature provides the resonant excitation of multiple surface plasma waves. In addition, a mirror is produced at the fiber tip by a chemical Tollens reaction. In this way, the sensor operates in a reflective mode, more convenient for dip probes. When these sensors are spectrally interrogated, a high sensitivity of 10-4 refractive index units per nanometer is attained. These devices can be advantageously used for any kind of chemical sensing and biosensing.
Esteban
Oscar
O
Departmento de Electrónica, Universidad de Alcalá, Escuela Politécnica, Alcalá de Henares, Madrid, Spain. oscar@depeca.uah.es
Díaz-Herrera
Natalia
N
Navarrete
María-Cruz
MC
González-Cano
Agustín
A