Mr Hamed Nikbakht, Prof Hamid Latifi, Ms Tahereh Amini, Dr Mohammad Ismail Zibaii,
Volume 8, Issue 2 (7-2014)
Abstract
In this paper, a tapered tip optical fiber probe sensor for localized refractive index (RI) measurements is presented. This sensor’s interaction with analytes is confined to a few micro-meters which makes it a promising candidate for in-vivo or even intra-cellular RI monitoring. This tapered tip was simply fabricated by etching optical fiber with hydrofluoric acid to a conic shape with a sub-micrometer aperture. The sensor was calibrated for RI measurement using different concentrations of NaCl in water. Limit of detection of 6.7×10-5 RIU was achieved for this low-cost sensor.
M. Sc. Jalil Jafari, Dr. Rahman Nouroozi,
Volume 11, Issue 1 (1-2017)
Abstract
For a fiber optical surface plasmon resonance (SPR) sensor a short part of its cladding should be removed to coat a thin layer of a metal. Usually this is problematic when an optical fiber with small core diameter is used. In this paper, a new method using µliter droplet of the HF acid for short fiber optical taper fabrication is reported. Using this method in a multi-mode optical fiber with the core/cladding size of 50/125 µm a 2 mm long taper with 40 µm diameter is fabricated. Roughness of its surface is investigated using an atomic force microscopy. The measured mean value of the roughness is about 8 nm. A 60 nm thin layer of pure silver is coated on the taper surface in order to investigate its performance using a fiber optical SPR sensor. Using this SPR fiber sensor measurement of the lead concentrations in water ranging from 0.1 to 10 part per million (ppm) is reported.
