Sensitivity Enhancement of Fiber Optic Diesel Adulteration Detection Sensor Using Stripped Clad S-Bend Section

A novel geometry for enhancing thesensitivity of intensity modulated refractometricfiber optic sensor for detection of adulterationlevel in diesel by kerosene is proposed. in thismultimode plastic optical fiber is uncladded forspecific length and bent into s shape. thisgeometry is simulated and analyzed using beampropagation method in beam prop rsoftsoftware. when sensor is immersed in the dieselthen diesel acts as a cladding for uncladded sshape portion of optical fiber. as diesel isadulterated by different volumes of kerosene,refractive index of cladding changes which inturn affects the output intensity of the sensor.the investigation revealed that when suchstructure of sensor is used to detect theadulteration level in diesel then sensitivity getsimproved 4 times for two fold increase in bendcurvature of fiber. thus it is highly sensitivemechanism to determine on line adulteration ofdiesel and also can be used for otherapplications.