Magnetic field sensor based on multi-port microcoil resonator

A multi-port microcoil resonator magnetic field sensor based on a microfiber coupler coil resonator (MMCR) is presented. The microfiber coupler coil is fabricated by coiling a four-port microfiber coupler with a uniform waist region around a low index support rod. The MMCR is embedded in a low refractive index polymer to increase the robustness and operation stability. The enhanced sensor response to the magnetic field is ascribed to the diverse MMCR response to the light polarization state. The MMCR magnetic field sensor is compact and low cost, and exhibits a magnetic field sensitivity of 37.09 dB/T with an estimated minimum detection limit (DL) of ~ 27 µT

Suspended-core microstructured polymer optical fibers and potential applications in sensing

The study of the fabrication, material selection, and properties of microstructured polymer optical fibers (MPOFs) has long attracted great interest. This ever-increasing interest is due to their wide range of applications, mainly in sensing, including temperature, pressure, chemical, and biological species. This manuscript reviews the manufacturing of MPOFs, including the most recent single-step process involving extrusion from a modified 3D printer. MPOFs sensing applications are then discussed, with a stress on the benefit of using polymers

Mid-IR hollow-core microstructured fiber drawn from a 3D printed PETG preform

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOMid-infrared (mid-IR) optical fibers have long attracted great interest due to their wide range of applications in security, biology and chemical sensing. Traditionally, research was directed towards materials with low absorption in the mid-IR region, such as chalcogenides, which are difficult to manipulate and often contain highly toxic elements. In this paper, we demonstrate a Polyethylene Terephthalate Glycol (PETG) hollow-core fiber (HCF) with guiding properties in the mid-IR. Guiding is provided by the fiber geometry, as PETG exhibits a material attenuation 2 orders of magnitude larger than the HCF propagation loss. The structured plastic fiber preforms were fabricated using commercial 3D printing technology and then drawn using a conventional fiber drawing tower. The final PETG fiber outer diameter was 466 mu m with a hollow-core diameter of 225 mu m. Thermal imaging at the fiber facet performed within the wavelength range 3.5-5 mu m clearly indicates air guidance in the fiber hollow-core.8118FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2014/50632-6Agências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Novel method for manufacturing optical fiber: extrusion and drawing of microstructured polymer optical fibers from a 3D printer

Microstructured polymer optical fibers (MPOFs) have long attracted great interest due to their wide range of applications in biological and chemical sensing. In this manuscript, we demonstrate a novel technique of manufacturing MPOF via a single-step procedure by means of a 3D printer. A suspended-core polymer optical fiber has been extruded and directly drawn from a micro-structured 3D printer nozzle by using an acrylonitrile butadiene styrene (ABS) polymer. Near-field imaging at the fiber facet performed at the wavelength λ~1550 nm clearly indicates guidance in the fiber core. The propagation loss has been experimentally demonstrated to be better than α = 1.1 dB/cm. This work points toward direct MPOFs manufacturing of varieties of materials and structures of optical fibers from 3D printers using a single manufacturing step

Microstructured polymer optical fibres fabricated from 3D printers for sensing applications

This research project had focused on the development of a novel optical fibre drawing technique based on a 3D printer to fabricate microstructured polymer optical fibres (MPOFs) in a single step for the sensing applications. The aim of this work is to overcome the drawbacks of the conventional drawing-tower based fabrication techniques, including the time-consuming, incapable of producing more complex non-geometrical structures, and high-cost. The research starts with studying the sensing capabilities of micro/nanofibre devices. A nanofibre coupler (NFC) operating near the cut-off region of the higher order supermodes for thermal and refractive index sensing was proposed and experimentally demonstrated. The microfibre coupler (MFC) was also considered for biological sensing applications due to its large evanescent field. DNA covalent attachment on the coupler surface has been demonstrated through the functionalisation, immobilization and hybridization processes. Covalent attachment and hybridization of the DNA on the MFC surface was confirmed via the fluorescent image that shows successful bonding to the complementary DNA strand that contains a fluorescent label. Then, the research was moved to establish new methods for manufacturing MPOFs sensors with built-in fluidic channels. The research started focusing on fibre preforms, with the design and 3D printing of a structured hollow-core polymer fibre preform. A commercial 3D printer was used to manufacture the preform, which was drawn into a hollow-core MPOF using a conventional fibre drawing tower. Guiding in the mid-IR was observed, with a propagation loss of 0.3 dB/mm at the wavelength of 4.5 µm. Although 3D printed structured polymer fibre preforms can be drawn into MPOF, large deformations in the fibre geometry were observed during the drawing process. Therefore, extrusion of MPOFs directly from a modified structured nozzle of a 3D printer was investigated. 3D printer nozzles, with structures complimentary to those of the MPOFs, were developed and fabricated by two techniques: micromachining and metal 3D printing. Simulations of heat transfer and material flow in the heated nozzle were also studied. Two structures of MPOFs were fabricated using this technique: the suspended-core fibre and the hexagonal hollow-core fibre. The suspendedcore fibre was fabricated for guiding in the optical communication and Terahertz (THz) bands, while the hollow-core fibre for mid-IR and THz. The microstructure inside the MPOFs was maintained, and guiding in near-IR, mid-IR, and THz region was observed. This research was the first successful attempt of direct extrusion of microstructured polymer optical fibres from a 3D printer which reduce the MPOF fabrication time and a step of optical fibre fabrication into a single step

A Review of Microfiber-Based Temperature Sensors

Optical microfiber-based temperature sensors have been proposed for many applications in a variety of industrial uses, including biomedical, geological, automotive, and defense applications. This increasing demand for these micrometric devices is attributed to their large dynamic range, high sensitivity, fast-response, compactness and robustness. Additionally, they can perform in-situ measurements remotely and in harsh environments. This paper presents an overview of optical microfibers, with a focus on their applications in temperature sensing. This review broadly divides microfiber-based temperature sensors into two categories: resonant and non-resonant microfiber sensors. While the former includes microfiber loop, knot and coil resonators, the latter comprises sensors based on functionally coated/doped microfibers, microfiber couplers, optical gratings and interferometers. In the conclusions, a summary of reported performances is presented

Designs of Silicon Nitride Slot Waveguide Modulators with Electro-Optic Polymer and the Effect of Induced Charges in Si-Substrate on Their Performance

Dimensional parameters are optimized comparing stoichiometric and Si-rich silicon nitride-based push-pull modulators using a slot waveguide structure, electro-optic polymer cladding, and in-plane ground-signal-ground electrode. An optical power confinement in slot spacing is examined for choosing the optimal device parameters for wavelength of 1550nm. The electrical simulations are set to calculate an asymmetric spatial distribution of poling efficiency and modulating refractive index change in polymer. The influence of carrier charge in Si-substrate is also considered. The voltage-length products as well as the poling efficiency of Si-rich SiN are calculated as 1.47 V·cm and 0.74 respectively for a polymer with a γ_(33,bulk) of 100 pm/V. For the selected polymer the calculated efficiency comparable to standard silicon based plasma dispersion depletion modulators. The efficiency can be increased more than two times for demonstrated polymers with a γ_(33,bulk) of ~230. Low metal absorption loss of ~ 1dB/cm can be achieved from the optimal designed device. Comparing to the conventional simulation method without Si-substrate effect, a more accurate simulation method is also presented in this work

A review of microfiber-based temperature sensors

Optical microfiber-based temperature sensors have been proposed for many applications in a variety of industrial uses, including biomedical, geological, automotive, and defense applications. This increasing demand for these micrometric devices is attributed to their large dynamic range, high sensitivity, fast-response, compactness and robustness. Additionally, they can perform in-situ measurements remotely and in harsh environments. This paper presents an overview of optical microfibers, with a focus on their applications in temperature sensing. This review broadly divides microfiber-based temperature sensors into two categories: resonant and non-resonant microfiber sensors. While the former includes microfiber loop, knot and coil resonators, the latter comprises sensors based on functionally coated/doped microfibers, microfiber couplers, optical gratings and interferometers. In the conclusions, a summary of reported performances is presented

Fast-response and High sensitivity nanofiber coupler thermometer

We report a high speed optical fibre thermometer based on a nanofiber coupler (NFC) working in the spectral region close to the odd supermode cut-off. The ~300 nm waist diameter nanofiber coupler was fabricated from two standard telecom fibres (Corning SMF-28) and was used as a compact temperature sensor from room temperature to 661 ℃. Due to its small size and the close proximity to the odd supermode cut-off, the NFC had a response time of ~ 7.2 ms and a temperature sensitivity of 55 pm/℃

Direct extrusion of suspended-core polymer optical fibers from 3D printers

We demonstrate the single-step manufacturing of a microstructured polymer optical fiber (MPOF) by extruding and directly drawing the polymer from a structured 3D printer nozzle.</p