Fabrication of an Atomic Resolution Low Cost STM-SNOM Hybrid Probe

2006 ◽  
Vol 6 (1) ◽  
pp. 72-76
Author(s):  
Ruggero Micheletto ◽  
Masatoshi Yokokawa ◽  
Satoshi Okazakaki ◽  
Yoichi Kawakami
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Chemical Etching ◽  
Low Cost ◽  
Resolving Power ◽  
Atomic Resolution ◽  
Hybrid Fiber ◽  
Horizontal Scale ◽  
Simple Method ◽  
One Step

We derived a simple method to fabricate STM-SNOM hybrid probes obtained from commercial cheap communication optical fibers. The tips are fabricated by a methodology that combines two well-known techniques: the selective attack by a buffered solution and the protected layer chemical etching, in a single new one-step technique. The tailored probes are then sputtered by metal and mounted on a STM setup. The usual difficulties of integrating the optical fiber in the STM head are solved originally with a particular home made mount described in details. We will show that the resulting probes reach atomic resolution on both vertical and horizontal scale, and that the optical imaging is free of artifacts and satisfactory with a lateral resolution in the order of λ/20, as far as we know the finest resolution obtained with a system based on a hybrid fiber probe. We believe that our methodology is very interesting for its simplicity of realization and for the good resolving power in both SNOM and STM modes.

scholarly journals Vortex Polymer Optical Fiber with 64 Stable OAM States

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2776
Author(s):  
José A. Borda-Hernández ◽  
Claudia M. Serpa-Imbett ◽  
Hugo E. Hernandez Figueroa
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Communication Systems ◽  
Low Cost ◽  
Higher Order ◽  
Coupling Coefficients ◽  
Polymer Optical Fiber ◽  
Optical Polymer ◽  
Polymer Optical Fibers ◽  
Low Dispersion

This research introduces a numerical design of an air-core vortex polymer optical fiber in cyclic transparent optical polymer (CYTOP) that propagates 32 orbital angular momentum (OAM) modes, i.e., it may support up to 64 stable OAM-states considering left- and right-handed circular polarizations. This fiber seeks to be an alternative to increase the capacity of short-range optical communication systems multiplexed by modes, in agreement with the high demand of low-cost, insensitive-to-bending and easy-to-handle fibers similar to others optical fibers fabricated in polymers. This novel fiber possesses unique characteristics: a diameter of 50 µm that would allow a high mechanical compatibility with commercially available polymer optical fibers, a difference of effective index between neighbor OAM modes of around 10−4 over a bandwidth from 1 to 1.6 µm, propagation losses of approximately 15 × 10−3 dB/m for all OAM modes, and a very low dispersion for OAM higher order modes (±l = 16) of up to +2.5 ps/km-nm compared with OAM lower order modes at a telecom wavelength of 1.3 µm, in which the CYTOP exhibits a minimal attenuation. The spectra of mutual coupling coefficients between modes are computed considering small bends of up to 3 cm of radius and slight ellipticity in the ring of up to 5%. Results show lower-charge weights for higher order OAM modes.

Femtosecond Laser One-Step Microfabrication of Optical Fiber Inline Square Resonators for Chemical Sensing

2007 ◽  
Author(s):  
Yukun Han ◽  
Songping Wu ◽  
Bala P. B. Chitturi ◽  
Hai-Lung Tsai ◽  
Tao Wei ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Chemical Etching ◽  
Three Dimensional ◽  
Q Factor ◽  
Sensing Applications ◽  
Post Annealing ◽  
Fs Laser ◽  
One Step ◽  
Silica Optical Fiber ◽  
First Time

We report, for the first time, the effort to one-step micromachine an optical fiber inline square resonator by femtosecond (fs) laser ablations. Such an inline square resonator is intended for infield chemical and biological sensing applications. Our preliminary data shows the feasibility of directly machining three dimensional microstructures on a silica optical fiber with a diameter of 125μm. The observed low quality (Q) factor can be further improved by post annealing and chemical etching processes that smooth the surface roughness.

scholarly journals An Optical Fiber Chemical Sensor for the Detection of Copper(II) in Drinking Water

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5246 ◽  
Author(s):  
Pesavento ◽  
Profumo ◽  
Merli ◽  
Cucca ◽  
Zeni ◽  
...  
Keyword(s):  
Drinking Water ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Chemical Sensor ◽  
Low Cost ◽  
Self Assembled Monolayer ◽  
Ph Values ◽  
Highly Sensitive ◽  
Selective Sensor

Highly sensitive plasmonic optical fiber platforms combined with receptors have been recently used to obtain selective sensors. A low-cost configuration can be obtained exploiting a D-shaped plastic optical fiber covered with a multilayer sensing surface. The multilayer consists of a gold film, functionalized with a specific receptor, where the surface plasmon resonance (SPR) occurs. The signal is produced by the refractive index variation occurring as a consequence of the receptor-to analyte binding. In this work, a selective sensor for copper(II) detection in drinking water, exploiting a self-assembled monolayer (SAM) of d,l-penicillamine as the sensing layer, has been developed and tested. Different concentrations of copper(II) in NaCl 0.1 M solutions at different pH values and in a real matrix (drinking water) have been considered. The results show that the sensor is able to sense copper(II) at concentrations ranging from 4 × 10-6 M to 2 × 10-4 M. The use of this optical chemical sensor is a very attractive perspective for fast, in situ and low-cost detection of Cu(II) in drinking water for human health concerns. Furthermore, the possibility of remote control is feasible as well, because optical fibers are employed.

scholarly journals Smartphone-Based Optical Fiber Sensor for the Assessment of a Fed-Batch Bioreactor

2020 ◽  
Vol 2 (1) ◽  
pp. 26
Author(s):  
Marco César Prado Soares ◽  
Thiago Destri Cabral ◽  
Pedro Machado Lazari ◽  
Matheus dos Santos Rodrigues ◽  
Gildo Santos Rodrigues ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Sucrose Concentration ◽  
Low Cost ◽  
Optical Fiber Sensor ◽  
Refraction Index ◽  
Fed Batch ◽  
Pixel Intensity ◽  
Batch Bioreactor ◽  
Sensing Platform

Industry is currently in a period of great expansion, the so-called “Industry 4.0”. This period relies on the development of new sensor technologies for the generation of systems capable of collecting, distributing, and delivering information. Particularly in chemical and biochemical industries, the development of portable monitoring devices can improve many process parameters, such as safety and productivity. In this work, the design of a smartphone-based optical fiber sensing platform for the online assessment of fed-batch fermentation systems is reported. The setup is comprised of a smartphone equipped with a 3D-printed case that couples optical fibers to the phone, and of an application for collecting images from the camera and then analyzing the pixel intensity. Finally, the obtained intensities are correlated to the broth refraction index, which is function of the sucrose concentration. We calculated the sensitivity of this sensor as 85.83 RIU−1 (refractive index units), and then compared its performance to results obtained with a handheld refractometer and with Monod model predictions. It showed to be a reliable, portable, and low-cost instrument for the online monitoring of bioreactors that can be easily reproducible on-site by simply printing it.

scholarly journals Fabrication of Antireflective Nanostructures on a Transmission Grating Surface Using a One-Step Self-Masking Method

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 180 ◽  
Author(s):  
Ting Shao ◽  
Feng Tang ◽  
Laixi Sun ◽  
Xin Ye ◽  
Junhui He ◽  
...  
Keyword(s):  
Effective Medium Theory ◽  
Low Cost ◽  
Fused Silica ◽  
Subwavelength Structures ◽  
Simple Method ◽  
Medium Theory ◽  
Transmission Grating ◽  
Wide Range ◽  
Nanostructure Surface ◽  
One Step

Suppression of Fresnel reflection from diffraction grating surfaces is very important for many optical configurations. In this work, we propose a simple method to fabricate subwavelength structures on fused-silica transmission grating for optical antireflection. The fabrication is a one-step self-masking reaction ion etching (RIE) process without using any masks. According to effective medium theory, random cone-shaped nanopillars which are integrated on the grating surface can act as an antireflective layer. Effects of the nanostructures on the reflection and transmission properties of the grating were investigated through experiments and simulations. The nanostructure surface exhibited excellent antireflection performance, where the reflection of the grating surface was suppressed to zero over a wide range of incident angles. Results also revealed that the etching process can change the duty cycle of the grating, and thus the diffraction orders if there are oblique lateral walls. The simulation results were in good agreement with the experimental ones, which verified our physical comprehension and the corresponding numerical model. The proposed method would offer a low-cost and convenient way to improve the antireflective performance of transmission-diffractive elements.

scholarly journals Binding Analysis of Functionalized Multimode Optical-Fiber Sandwich-like Structure with Organic Polymer and Its Sensing Application for Humidity and Breath Monitoring

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 324
Author(s):  
Daniel Jauregui-Vazquez ◽  
Paulina Lozano-Sotomayor ◽  
Jorge Emmanuel Mejía-Benavides ◽  
Erik Díaz-Cervantes
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Molecular System ◽  
Low Cost ◽  
Computational Simulation ◽  
Fiber Surface ◽  
Cost Effective ◽  
Effective Alternative ◽  
Organic Polymer ◽  
Cost Effective Alternative

In recent years, the chemical modification of optical fibers (OFs) has facilitated the manufacture of sensors because OFs can identify several analytes present in aqueous solutions or gas phases. Nevertheless, it is imperative better to understand the chemical interactions in this molecular system to generate low-cost and efficient sensors. This work presents a theoretical and experimental study of organic polymeric functionalized OF structures and proposes a cost-effective alternative to monitor breathing and humidity. The device is based on silicon optical fibers functionalized with (3-Aminopropyl) triethoxysilane (APTES) and alginate. The theoretical analysis is carried out to validate the activation of the silicon dioxide fiber surface; moreover, the APTES–alginate layer is discussed. The computational simulation suggests that water can be absorbed by alginate, specifically by the calcium atom linked to the carboxylic acid group of the alginate. The analysis also demonstrates a higher electrostatic interaction between the water and the OF–APTES–alginate system; this interaction alters the optical fiber activated surface’s refractive index, resulting in transmission power variation. The humidity analysis shows a sensitivity of 3.1288 mV/RH, a time response close to 25 s, and a recovery time around 8 s. These results were achieved in the range of 50 to 95% RH. Moreover, the recovery and response time allow the human breath to be studied. The proposed mechanism or device is competitive with prior works, and the components involved made this sensor a cost-effective alternative for medical applications.

scholarly journals Characterization of Hand Gestures by a Smartphone-Based Optical Fiber Force Myography Sensor

2020 ◽  
Vol 2 (1) ◽  
pp. 46
Author(s):  
Matheus S. Rodrigues ◽  
Pedro M. Lazari ◽  
Marco C. P. Soares ◽  
Eric Fujiwara
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Low Cost ◽  
Optical Fiber Sensor ◽  
Hand Gestures ◽  
Optical Signals ◽  
Integrated Optical ◽  
Reliable Performance ◽  
Force Myography ◽  
Polymer Optical Fibers

In this paper, a smartphone-integrated, optical fiber sensor based on the force myography technique (FMG), which characterizes the stimuli of the forearm muscles in terms of mechanical pressures, was proposed for the identification of hand gestures. The device’s flashlight excites a pair of polymer optical fibers and the output signals are detected by the camera. The light intensity is modulated through wearable, force-driven microbending transducers placed in the forearm and the acquired optical signals are processed by an algorithm based on decision trees and residual error. The sensor provided a hit rate of 87% regarding four postures, yielding reliable performance with a simple, portable, and low-cost setup embedded on a smartphone.

scholarly journals Swelling-Based Distributed Chemical Sensing with Standard Acrylate Coated Optical Fibers

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 718
Author(s):  
Sina Sedighi ◽  
Marcelo A. Soto ◽  
Alin Jderu ◽  
Dorel Dorobantu ◽  
Marius Enachescu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Chemical Sensing ◽  
Low Cost ◽  
Refractive Index Change ◽  
Water Quality Monitoring ◽  
Medical Diagnostics ◽  
Optical Frequency Domain Reflectometry ◽  
Frequency Domain Reflectometry ◽  
Agriculture Water

Distributed chemical sensing is demonstrated using standard acrylate coated optical fibers. Swelling of the polymer coating induces strain in the fiber’s silica core provoking a local refractive index change which is detectable all along an optical fiber by advanced distributed sensing techniques. Thermal effects can be discriminated from strain using uncoated fiber segments, leading to more accurate strain readings. The concept has been validated by measuring strain responses of various aqueous and organic solvents and different chain length alkanes and blends thereof. Although demonstrated on a short range of two meters using optical frequency-domain reflectometry, the technique can be applied to many kilometer-long fiber installations. Low-cost and insensitive to corrosion and electromagnetic radiation, along with the possibility to interrogate thousands of independent measurement points along a single optical fiber, this novel technique is likely to find applications in environmental monitoring, food analysis, agriculture, water quality monitoring, or medical diagnostics.

Heating and Burning of Optical Fibers and Cables by Light Scattered from Bubble Train Formed by Optical Fiber Fuse

2012 ◽  
Vol E95.B (8) ◽  
pp. 2638-2641 ◽  
Author(s):  
Makoto YAMADA ◽  
Akisumi TOMOE ◽  
Takahiro KINOSHITA ◽  
Osanori KOYAMA ◽  
Yutaka KATUYAMA ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

Sign in / Sign up

Export Citation Format

Share Document