Compact magnetic field sensor based on plasmonic fiber-tip

Capacitive Bionic Magnetic Sensors Based on One-Step Biointerface Preparation

Magnetic biomolecule-based bionic magnetic field sensors are anticipated to open up novel pathways for magnetic field detection. The detection range and accuracy of current bionic magnetic field sensors are limited, and little work is based on the capacitive response principle. We successfully developed a biochemical interface with an extralarge target-receptor size ratio, which can be manufactured in a single step for weak magnetic field detection across a wide frequency range, and we used electrochemical capacitance as a magnetic field change conduction strategy. The thickness-controllable nanoscale bovine serum albumin/graphene layer on an indium tin oxide working electrode combines with the one-step preparation method to immobilize the MagR/Cry4 complex. This capacitive bionic magnetic sensor can achieve the detection range of 0-120 mT. This biointerface design strategy obtains the further improvement of the performance of this bionic magnetic field sensor. Furthermore, the biointerface construction and optimization methodology in this proposal has potential applications in the design of other medical biosensors.

Plasmonic Functionality of Optical Fiber Tips: Mechanisms, Fabrications, and Applications

Optical fiber tips with the flat end-facets functionalized take the special advantages of easy fabrication, compactness, and ready-integration among the community of optical fiber devices. Combined with plasmonic structures, the fiber tips draw a significant growth of interest addressing diverse functions. This review aims to present and summarize the plasmonic functionality of optical fiber tips with the current state of the art. Firstly, the mechanisms of plasmonic phenomena are introduced in order to illustrate the tip-compatible plasmonic nanostructures. Then, the strategies of plasmonic functionalities on fiber tips are analyzed and compared. Moreover, the classical applications of plasmonic fiber tips are reviewed. Finally, the challenges and prospects for future opportunities are discussed.

AC field modulated DC magnetic field sensor based on optical whispering gallery mode microcapillary resonator

A sensitive DC magnetic field sensor is constructed by measuring the signal-to-noise ratio of an AC-modulated magnetic field at a particular frequency from an optical whispering gallery mode microcapillary resonator. The sensing element consists of an optical whispering gallery mode microcapillary resonator bonded to a magnetostrictive material that enables it to respond to external magnetic fields. A DC magnetic field sensitivity of 0.1703dB/Oe and a linear detection range from 4.8Oe to 65.7Oe are realized under an AC modulation field of 168.1kHz in the unshielded environment at room temperature. To our best knowledge, this sensitivity is about 2.3 times of the maximum sensitivity of other DC magnetic field sensors based on magnetic fluid or magnetostrictive material integrated fiber systems that use the dissipative sensing scheme. Furthermore, the sensor can operate at a stable temperature in the range of [-11∼45]°C, as long as the modulation frequency of the AC-modulation field is adjusted according to the ambient temperature. This sensor provides us with a novel DC magnetic field sensing scheme, which may play a role in industrial fields related to current and position detection in the future.