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 th...

this paper presents design and construction of an automatic moldboard profilograph by substituting an optical sensor and a control system together with its evaluation. the modified profilograph is an electro mechanical apparatus in which a micro switch and a dc motor was replaced with an optical sensor and a control system for revolution of a dc motor. thereby, the considered surface is measure...

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-m...

A novel geometry for enhancing the sensitivity of intensity modulated refractometric fiber optic sensor for detection of adulteration level in diesel by kerosene is proposed. In this multimode plastic optical fiber is uncladded for specific length and bent into S shape. This geometry is simulated and analyzed using Beam Propagation Method in Beam prop RSOFT software. When sensor is immersed in ...

The characterization of and construction of a new optical sensor based on the immobilization of Pyrocatechol Violet on a triacetylcellulose membrane was described to for the determination of bismuth (III) in real samples. The interaction between sensing membrane and bismuth (III) was caused at pH 3.80 in acetate buffer solution and the color changed from yellow to blue along with the appearance...

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 w...

The development of an optical pH sensor based on immobilization of quinizarin (1,4-dihydroxyanthraquinone) on a triacetylcellulose membrane was described. The resulting membrane exhibited fast color change from yellow to violet, while changing the pH in alkaline region. The immobilized quinizarin showed a broader dynamic range from (pH 9.4-11.4) with respect to free form (pH 8.8-10.4). The sens...