Ferrule Endface Research Articles

Ferrule Endface Dimension Optimization for Standard Outer Diameter 4-Core Fiber Connector

Ferrule Endface Dimension Optimization for Standard Outer Diameter 4-Core Fiber Connector

Ampere force fiber optic magnetic field sensor using a Fabry-Perot interferometer.

The paper presents a novel fiber-optic vector magnetic field sensor using a Fabry-Perot interferometer, which consists of an optical fiber end face and a graphene/Au membrane suspended on the ceramic ferrule end face. A pair of gold electrodes are fabricated on the ceramic ferrule by femtosecond laser to transmit electrical current to the membrane. Ampere force is generated when an electrical current flows through the membrane in a perpendicular magnetic field. The change in Ampere force causes a shift in the resonance wavelength in the spectrum. In the magnetic field intensity range of 0 ∼ 180 mT and 0 ∼ -180 mT, the as-fabricated sensor exhibits magnetic field sensitivity of 5.71 pm/mT and 8.07 pm/mT. The proposed sensor has great potential application in weak magnetic field measurements due to its compact structure, cost-effectiveness, ease to manufacture, and good sensing performance.

Optical-thermally actuated graphene mechanical resonator for humidity sensing

This paper demonstrates an optical-thermally actuated multi-layer graphene resonator for humidity sensing. A ∼10-layered graphene resonator with a diameter of 125 µm peripherally clamped on the fiber ferrule end face was actuated to vibrate using the intensity-modulated laser, and the vibration was detected based on the optical fiber Fabry-Perot interference method. The humidity sensing experiment exhibited an up to 350 Hz/%RH humidity sensitivity in the range of 0–100 % RH at 25 °C, which was 10 times higher than those of the previously reported Quartz Crystal Microbalance (QCM)-based humidity sensors. Also, a good repeatability of the frequency-humidity response was observed for the presented graphene resonator. Moreover, in view of the coupling effect of temperature on the graphene resonator, the temperature drift of 0.942 kHz/°C was measured in the range of 25–50 °C, thereby inducing an absolute humidity error of about 0.6 g/(m3·°C).

Research of Fiber Optic Connector Ferrule End-Face Degradation Influence on Optical Pulse Distortion during Propagation over Indoor Multi-Gigabit Optical Network Link with Crypto-Fibers

This article presents results of approbation of developed model of piece-wise regular fiber optic link, operating in a few-mode regime, with series-connected couple of special multimode optical crypto-fibers “encryptor-decoder”. Unlike the previously developed solution, the model was modified with an ability to take into account influence of fiber optic connector end-face contamination on laser-excited optical signal launching conditions. We present comparison results of computed optical pulse response envelops, distorted during propagation over 10GBase-LX network fiber optic links, containing optical crypto-fibers, depending on various conditions of transceiver laser source connector ferrule end-face contamination.

Adhesive-free bonding homogenous fused-silica Fabry–Perot optical fiber low pressure sensor in harsh environments by CO2 laser welding

Abstract In this paper, we present a high-sensitivity homogenous fused-silica low pressure sensor. It was constructed from the commercially available standard silica fiber, fused-silica diaphragm and ferrule through CO2 laser all-welding. A Fabry–Perot (FP) cavity was fully sealed between the ultra-thin fused-silica diaphragm and the ferrule end face, and the ultra-thin diaphragm acts as a pressure transducer. We proposed the laser heat conduction welding for the fused-silica diaphragm, and the laser deep penetration point welding for the fiber and the ferrule. So the monolithic structure fused-silica FP interference optical fiber sensor was achieved. The sensor has a vent hole between the fiber and the ferrule forming during the laser deep penetration point welding, which can effectively reduce temperature dependence. The sensor exhibits excellent stability and repeatability, extreme low temperature dependence with 0.025nm/ o C that is 1/76 of the theoretical value, a sensitivity of 5.15nm/kPa, and a resolution of 4.7Pa. With a monolithic fused-silica configuration, the adhesive-free bonding high-sensitivity fused-silica sensor is expected to be suitable for low pressure measurements in extreme harsh environments.

Graphene Oxide-Based Q-Switched Erbium-Doped Fiber Laser

We demonstrate a pulsed ring erbium-doped fiber laser based on graphene oxide (GO), employing a simplified Hummer's method to synthesize the GO via chemical oxidation of graphite flakes at room temperature. By dipping a fiber ferrule end face onto the GO suspension, GO is successfully coated onto the end face, making it a simple saturable absorption device. A stable Q-switched pulsed fiber laser is achieved with a low pump threshold of 9.5 mW at 980 nm. The pulse repetition rate ranges from 16.0 to 57.0 kHz. The pulse width and the pulse energy are studied and discussed.

High-Speed MT Connector Assembly Method

This paper describes a high-speed MT connector assembly method. This technique uses adhesive with a short hardening time, is highly reliable and does not require a polishing process, thus reducing the connector assembly time. First, we investigated an alpha-cyanoacrylate adhesive that hardens quickly and whose adhesive strength does not decrease under high humidity and high temperature conditions, thus ensuring its excellent reliability for outside use. In addition, we investigated variations in the position of the fiber endface on the ferrule endface with a view to obtaining a low insertion loss. Based on the results, we assembled an MT connector using our proposed high-speed assembly method. We confirmed that the assembly time could be reduced to less than 70% of the time required with the conventional method. MT connectors assembled using this technique have a low insertion loss and stable environmental characteristics.

Characteristics of fibre-optic connector at high-power optical incidence

The high-power characteristics of the MU-type fibre-optic connector are investigated systematically for the first time. It is clarified that a connector with a low insertion loss of below 0.25 dB suppressed the undesirable temperature increase to less than 10° with an optical input of 1 W, and appropriate ferrule endface cleaning prevented endface damage.

Development of a New Processing Method for Fiber Protrusion of Multi-fiber Connector.

A novel ultrasonic vibration polishing method was developed by introducing an assistant ferrule between the multi fiber connector and the ultrasonic vibrator, which enabled the ferrule endface to be processed exclusively without contact with fiber endface. By this method, the desired fiber protrusions of all the fibers in multi fiber connector were obtained efficiently in a short time so that good optical characteristics were achieved. Insertion loss difference of single mode 12 fiber connector with and without index-matching material was less than 0.04dB, and optical characteristics of 12 fiber connector without index matching material remained stable during the reconnections of 500 cycles. Good and stable physical contact (PC) connection was achieved. Compared with the conventional method, this novel method raises the processing efficiency greatly.

Improved design of APC optical connectors with slanted angle of 12° for dispersion shifted optical fiber

This paper describes improved design criteria for a highly stable angled physical contact (APC) connector with a slanted angle of 12/spl deg/ for a dispersion shifted optical fiber, which is derived from the theoretical considerations based on experiments. A shift of the vertex point of the convex ferrule endface from the optical fiber axis is minimized, so that compatibility among APC connectors can be established by using a new type of stepped-ferrule developed by the author. When rotation angle between the mating ferrules was less than 4/spl deg/ in a circular direction, the insertion losses for the improved APC connectors consisting of stepped-ferrules were 0.23/spl plusmn/0.45 dB, while the insertion losses for the conventional APC connectors consisting of tapered-ferrules measured 0.39/spl plusmn/0.89 dB. It can be confirmed that slanted angle of the convex ferrule endface is required to be 12/spl deg/ to obtain a backreflection of less than -60 dB for the dispersion shifted optical fiber at the wavelength of 1.550 /spl mu/m.

光ファイバ端面の斜め球面研磨装置とその研磨実験

This paper describes an angled-convex-polishing apparatus for optical fiber endfaces, which is used for APC connectors (angled-physical-contact optical connectors), and its evaluation. This apparatus constructed utilizing an elastic-polishing-plate is driven in accordance with combined orbital and rotational motion. When a slanted angle of the ferrule endface was 8 degrees, the diameter of the ferrule endface wasranging from 1 to 2 mm, the Shore-hardness of the elastic-plate was Hs 70, and the polishing load was 200 gf/mm2, both the physical and optical performance obtained from an experimental study were as follows : An angled-convex radius on the ferrule endface was from 5.4 to 10.6 mm, a shift of the vertex on the convex surface from the optical fiber axis was less than 38.5lam, the withdrawal of the optical fiber endface from the ferrule endface was less than 0.046 μm, the backreflection was less than - 66 dB, and the insertion loss was less than 0.41 dB.

Elastic polishing plate method and conditions for forming angled convex surface on ferrule endface

This paper describes an apparatus for forming an angled convex surface at the ferrule endface by polishing the ferrule endface utilizing an elastic polishing plate performing orbital and rotational motion. When the diameter of the ferrule tip was greater than approximately 0.4 mm and when the Shore hardness of the elastic plate was approximately softer than 95, the formed convex radius on the ferrule endface was found to be an unique function of both the deformed depth of the elastic polishing plate and the diameter of the ferrule tip. The backreflection of the light beam from the polished optical fiber endface was as low as less than -64 dB for all tested samples when singlemode optical fibers were polished at a slanted angle of 8 degrees.

Advanced physical contact technology for optical connectors

An advanced low-reflection PC (physical contact) optical connector with an average return loss of 46 dB has been realized while maintaining a reliability as high as that of conventional PC optical connectors. The high return loss and reliability of the APC have been achieved by suppressing damaged layer generation and by reducing fiber withdrawal from the ferrule endface. Slight variations in the damaged layer significantly affect the return loss and distribution of the APC connector, because the refractive index of the layer is very close to that of silica fiber core.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Connection mechanism of physical-contact optical fiber connectors with spherical convex polished ends

We present an experimental and analytical investigation of the connection mechanism of physical-contact optical-fiber connectors with spherical convex polished ends and confirm that reducing the curvature radius of the spherical convex ferrule end face is effective for establishing a stable connection with slight axial compressive force on the ferrules.