Magnetic Field Sensor Based on Nonadiabatic Tapered Optical Fiber With Magnetic Fluid

Abstract

A novel magnetic field sensor using a nonadiabatic tapered optical fiber (NATOF) interacting with magnetic fluid (MF) nanoparticles is proposed and experimentally demonstrated. The NATOF sensitivity when is subjected to refractive index (RI) measurement in the small range from 1.3380 to 1.3510 was 1260.17 nm/RIU as a refractometer sensor. The NATOF is surrounded by a MF whose RI changes with external magnetic field, which MF is as a cladding of tapered fiber. The output interference spectrum is shifted by the change of the applied magnetic field intensity in the range up to 44 mT with a sensitivity of −7.17 × 10 −2 nm/mT, used only 0.1% of the volume concentration of MF nanoparticles. This direct manipulation of light with magnetic fields provides an approach to develop future sensors relying on electromagnetic interactions.

A sensitive tapered-fiber optic biosensor for the label-free detection of organophosphate pesticides

“…According to Eq. (1), the interference signal of a non-adiabatic tapered fiber reaches its minimum when the phase difference Δφ of the cosine term becomes an odd multiple of π [27], that is I = I min , when:…”

Transmissive optical fiber magnetic field sensor based on ferrofluids

“…This magnetooptic effect has been used in conjunction with fiber optic technology to realize an assortment of magnetic field sensors. For instance, fiber sensors have been reported based on submerging a microfiber knot into a ferrofluid [2], dipping single-mode fiber (SMF) tapers into a ferrofluid, [3,4], using a ferrofluid as an outer cladding of an etched multimode (MM) fiber, a coreless multimode fiber in a SMF/MMF/SMF optical structure [5,6] or a fiber grating etched within a D-shaped fiber [7]. These sensors require complex modification of the basic commercial fiber optic structure.…”

A Photonic Crystal Magnetic Field Sensor Using a Shoulder-Coupled Resonant Cavity Infiltrated with Magnetic Fluid

“…Many optical devices based on MF have been proposed in the past decades [6,7,8,9,10,11,12]. Compared with the traditional devices, MF-based optical devices have the advantages of high sensitivity and a small size, which makes them promising for broad applications in the fields of photonics and sensing [13,14,15,16,17,18,19]. …”