scholarly journals Efficient, low-cost optical coupling mechanism for TiO2-SiO2 sol-gel derived slab waveguide surface grating coupler sensors

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Andrzej Kaźmierczak ◽  
Mateusz Słowikowski ◽  
Krystian Pavłov ◽  
Maciej Filipiak ◽  
Michael Vervaeke ◽  
...  
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Optical Signal ◽  
Slab Waveguide ◽  
Coupling Scheme ◽  
Coupling Mechanism ◽  
Grating Coupler ◽  
Surface Grating ◽  
Fresnel Lenses ◽  
Waveguide Surface

We present an optical signal coupling scheme for slab waveguide surface grating coupler sensors. The proposed solution is based on the use of polymer microlenses. In this work we analyze two types of compact polymer lenses: the aspheric plano-convex lenses and Fresnel lenses. The feasibility of the proposed scheme is demonstrated by the experimental investigation into the optical signal coupling to the test structure of TiO2-SiO2 slab waveguide surface grating coupler using both types of lenses.

scholarly journals A simple approach to prepare fluorescent molecularly imprinted nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7732-7737
Author(s):  
Fenying Wang ◽  
Dan Wang ◽  
Tingting Wang ◽  
Yu Jin ◽  
Baoping Ling ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Sol Gel ◽  
Silica Sol ◽  
Simple Approach ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Low Toxicity ◽  
Good Biocompatibility ◽  
Molecularly Imprinted Nanoparticles

Fluorescent molecularly imprinted polymer (FMIP) gains great attention in many fields due to their low cost, good biocompatibility and low toxicity. Here, a high-performance FMIP was prepared based on the autocatalytic silica sol–gel reaction.

scholarly journals Synthesis and characterization of Mg–Zn ferrite based flexible microwave composites and its application as SNG metamaterial

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Tariqul Islam ◽  
Mandeep Singh Jit Singh ◽  
Md Samsuzzaman ◽  
Muhammad E. H. Chowdhury
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Microwave Frequency ◽  
Dielectric Substrate ◽  
Dielectric Constants ◽  
Potential Candidate ◽  
Flexible Composites ◽  
Average Grain Size ◽  
Zn Ferrite ◽  
High Flexibility

AbstractIn this article, we propose SNG (single negative) metamaterial fabricated on Mg–Zn ferrite-based flexible microwave composites. Firstly, the flexible composites are synthesized by the sol-gel method having four different molecular compositions of MgxZn(1−x)Fe2O4, which are denoted as Mg20, Mg40, Mg60, and Mg80. The structural, morphological, and microwave properties of the synthesized flexible composites are analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and conventional dielectric assessment kit (DAK) to justify their possible application as dielectric substrate at microwave frequency regime. Thus the average grain size is found from 20 to 24 nm, and the dielectric constants are 6.01, 5.10, 4.19, and 3.28, as well as loss tangents, are 0.002, 0.004, 0.006, and 0.008 for the prepared Mg–Zn ferrites, i.e., Mg20, Mg40, Mg60, and Mg80 respectively. Besides, the prepared low-cost Mg–Zn ferrite composites exhibit high flexibility and lightweight, which makes them a potential candidate as a metamaterial substrate. Furthermore, a single negative (SNG) metamaterial unit cell is fabricated on the prepared, flexible microwave composites, and their essential electromagnetic behaviors are observed. Very good effective medium ratios (EMR) vales are obtained from 14.65 to 18.47, which ensure the compactness of the fabricated prototypes with a physical dimension of 8 × 6.5 mm2. Also, the proposed materials have shown better performances comparing with conventional FR4 and RO4533 materials, and they have covered S-, C-, X-, Ku-, and K-band of microwave frequency region. Thus, the prepared, flexible SNG metamaterials on MgxZn(1−x)Fe2O4 composites are suitable for microwave and flexible technologies.

scholarly journals All-Optical Non-Inverted Parity Generator and Checker Based on Semiconductor Optical Amplifiers

2021 ◽  
Vol 11 (4) ◽  
pp. 1499
Author(s):  
Bingchen Han ◽  
Junyu Xu ◽  
Pengfei Chen ◽  
Rongrong Guo ◽  
Yuanqi Gu ◽  
...  
Keyword(s):  
Optical Amplifiers ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Extinction Ratio ◽  
Semiconductor Optical Amplifiers ◽  
Optical Signal ◽  
Probe Light ◽  
All Optical ◽  
Negative Effect ◽  
Parity Generator

An all-optical non-inverted parity generator and checker based on semiconductor optical amplifiers (SOAs) are proposed with four-wave mixing (FWM) and cross-gain modulation (XGM) non-linear effects. A 2-bit parity generator and checker using by exclusive NOR (XNOR) and exclusive OR (XOR) gates are implemented by first SOA and second SOA with 10 Gb/s return-to-zero (RZ) code, respectively. The parity and check bits are provided by adjusting the center wavelength of the tunable optical bandpass filter (TOBPF). A saturable absorber (SA) is used to reduce the negative effect of small signal clock (Clk) probe light to improve extinction ratio (ER) and optical signal-to-noise ratio (OSNR). For Pe and Ce (even parity bit and even check bit) without Clk probe light, ER and OSNR still maintain good performance because of the amplified effect of SOA. For Po (odd parity bit), ER and OSNR are improved to 1 dB difference for the original value. For Co (odd check bit), ER is deteriorated by 4 dB without SA, while OSNR is deteriorated by 12 dB. ER and OSNR are improved by about 2 dB for the original value with the SA. This design has the advantages of simple structure and great integration capability and low cost.

scholarly journals Performance Improvement of ZnSnO Thin-Film Transistors with Low-Temperature Self-Combustion Reaction

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1099
Author(s):  
Ye-Ji Han ◽  
Se Hyeong Lee ◽  
So-Young Bak ◽  
Tae-Hee Han ◽  
Sangwoo Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Low Cost ◽  
Thermal Analyses ◽  
Thin Film Transistor ◽  
Sol Gel ◽  
Annealing Temperatures ◽  
Zinc Tin Oxide ◽  
Thermal Limitation

Conventional sol-gel solutions have received significant attention in thin-film transistor (TFT) manufacturing because of their advantages such as simple processing, large-scale applicability, and low cost. However, conventional sol-gel processed zinc tin oxide (ZTO) TFTs have a thermal limitation in that they require high annealing temperatures of more than 500 °C, which are incompatible with most flexible plastic substrates. In this study, to overcome the thermal limitation of conventional sol-gel processed ZTO TFTs, we demonstrated a ZTO TFT that was fabricated at low annealing temperatures of 350 °C using self-combustion. The optimized device exhibited satisfactory performance, with μsat of 4.72 cm2/V∙s, Vth of −1.28 V, SS of 0.86 V/decade, and ION/OFF of 1.70 × 106 at a low annealing temperature of 350 °C for one hour. To compare a conventional sol-gel processed ZTO TFT with the optimized device, thermogravimetric and differential thermal analyses (TG-DTA) and X-ray photoelectron spectroscopy (XPS) were implemented.

Cryogenic and Fluidic Ways Lead to Low Cost Micro/Nano Devices

2009 ◽  
Author(s):  
Jing Liu ◽  
Yang Yang
Keyword(s):  
Chemical Reaction ◽  
Basic Principle ◽  
Low Cost ◽  
Modern Science ◽  
Small World ◽  
Optical Signal ◽  
Membrane Thickness ◽  
Major Theme ◽  
Science And Engineering Practices ◽  
Characterization Procedure

Building systems as compactly as possible has been a major theme in modern science and engineering practices. However, such enthusiastic endeavor often encounters big troubles due to high cost and complexity of the process it involves. Part of the reasons comes from the methodology itself, the fabrication, designing and characterization procedure etc. Among various disciplines to making micro/nano object, those enabled from the thermal and hydrodynamic science plays a rather important role. In this article, we will illustrate a cryogenic way for realizing a group of different micro/nano devices which can be implemented as mechanical, hydraulic, electrical, or optical functional units. The basic principle of the method lies in the formation of ice crystals in small area, from which micro/nano aqueous objects or signals transmitting across them can be blocked, manipulated and analyzed. In this way, a series of micro/nano devices such as freeze tweezer, ice valve, freeze-thaw pump, electrical or optical signal switch and micro thermal analyzer etc. can be developed via a rather simple and low cost way. As examples, some latest advancement made in the authors’ lab will be reviewed. Their innovative applications in a wide variety of micro/nano engineering fields will be discussed. Further, to illustrate the low cost way to directly manufacture micro/nano objects, we will explain a bubble fabrication method whose basic principle lies in the chemical reaction occurring at the fluidic interfaces between two or more soap adjacent bubbles. A unique virtue of the bubble is that it can have a rather huge diameter however an extremely small membrane thickness, whose smallest size can even reach nano scale. Therefore, the administrated chemical reaction in the common interface of the contacting bubbles would lead to products with extremely small size. Particularly, all these results were achieved via a rather straightforward way. The bubble builds up a bridge between the macroscopic manipulation/observation and the fabrication in small world. Several typical micro structures as fabricated in the lab will be illustrated. As a flexible, easily controllable, and low cost method, the bubble fabrication can possibly be developed as a routine strategy for making micro/nano structures in the near future.

Switchable and tunable linear cavity erbium-doped fiber laser based on FBGs embedded in Sagnac rings

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 015101
Author(s):  
Gangxiao Yan ◽  
Weihua Zhang ◽  
Peng Li ◽  
Qiuhao Jiang ◽  
Meng Wu ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Low Cost ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Hole Burning ◽  
Linear Cavity ◽  
Erbium Doped ◽  
Optical Fiber Sensing ◽  
Birefringence Effect

Abstract A switchable and tunable erbium-doped fiber laser with a linear cavity based on fiber Bragg gratings embedded in Sagnac rings is proposed and experimentally verified. Due to the stress birefringence effect and the polarized hole burning effect, which are introduced into the single-mode fiber in the polarization controllers (PCs) by the PCs, the designed laser can achieve seven kinds of laser-states output including three kinds of single-wavelength laser states, three kinds of dual-wavelength laser states and one kind of triple-wavelength laser state. The optical signal-to-noise ratios of the output wavelengths are all higher than 52 dB, and the wavelength shifts are all less than 0.04 nm. Furthermore, the temperature tuning of the wavelength range is also researched, which is about 1.2 nm. Due to advantages, such as low cost, simple structure, easy switching and multiple laser states, the designed laser has great application potential in laser radar, optical fiber sensing and so on.

Photophysical Properties of CdS Nanoparticles in Thin Films for Opto-Chemical Sensing

2004 ◽  
Vol 820 ◽  
Author(s):  
Elena A. Guliants ◽  
Barbara A. Haruff ◽  
James R. Gord ◽  
Christopher E. Bunker
Keyword(s):  
Thin Films ◽  
Organic Compounds ◽  
Protective Coatings ◽  
Photophysical Properties ◽  
Sol Gel ◽  
Liquid Solution ◽  
Optical Signal ◽  
Cds Nanoparticles ◽  
Trap States ◽  
Post Synthesis

AbstractIn recent years, II-VI compound semiconductor nanoparticles synthesized in a liquid solution have been shown to possess unique optoelectronic properties which are highly attractive for the fabrication of various sensors based on the optical signal readout scheme. The challenge has been to immobilize these nanoparticles into films on solid surfaces, i.e. on a chip, so that they do not suffer any property deterioration as a sensing medium. In the presented work, synthesis of CdS nanoparticles in reverse micelle solution using AOT surfactant as a stabilizer has led to particles with relatively bright photoemission identified as originating from both shallow and deep traps inside the bandgap. Moreover, slightly altering the preparation procedure has produced samples with two distinctive crystal structures. Both types of CdS nanoparticles suspended in commonly utilized solvents such as chloroform and hexane were subject to chemical quenching when various organic compounds were introduced into the solution, demonstrating the sensitivity of trap states to their chemical environment. However, the two structures have shown very different optical properties. While post-synthesis treatment had no effect on one type of particle, the other type was able to undergo a photochemical reaction via prolonged UV irradiation, which resulted in an increased luminescence quantum yield ÖL from 2% to 14%. The same particle type was also responsive to thermal treatment, showing even higher values of ÖL (∼40%). The CdS/AOT particles have been cast into thin films by spin-coating on a Si wafer. Coating parameters have been investigated in order to achieve optimal control over the film thickness, uniformity, overall film durability, etc. These nanostructured films capped with various porous polymeric and sol-gel protective coatings were exposed to a series of organic compounds. Photoluminescence data collected for these samples served for identification of the compounds and their concentrations. This paper offers the discussion of photophysical response in CdS nanoparticle-based thin films with respect to development of novel nanostructured opto-chemical sensors.

Sol-gel-derived gallium nitride thin films for ultraviolet photodetection

2019 ◽  
Vol 36 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Chee Yong Fong ◽  
Sha Shiong Ng ◽  
NurFahana Mohd Amin ◽  
Fong Kwong Yam ◽  
Zainuriah Hassan
Keyword(s):  
Thin Films ◽  
Dark Current ◽  
Uv Light ◽  
Low Cost ◽  
Sol Gel ◽  
Contrast Ratio ◽  
Uv Photodetector ◽  
Content Type ◽  
Barrier Heights ◽  
Coating Method

Purpose This study aims to explore the applicability of the sol-gel-derived GaN thin films for UV photodetection. Design/methodology/approach GaN-based ultraviolet (UV) photodetector with Pt Schottky contacts was fabricated and its applicability was investigated. The current-voltage (I-V) characteristics of the GaN-based UV photodetector under the dark current and photocurrent were measured. Findings The ideality factors of GaN-based UV photodetector under dark current and photocurrent were 6.93 and 5.62, respectively. While the Schottky barrier heights (SBH) for GaN-based UV photodetector under dark current and photocurrent were 0.35 eV and 0.34 eV, respectively. The contrast ratio and responsivity of this UV photodetector measured at 5 V were found to be 1.36 and 1.68 μA/W, respectively. The photoresponse as a function of time was measured by switching the UV light on and off continuously at different forward biases of 1, 3 and 6 V. The results showed that the fabricated UV photodetector has reasonable stability and repeatability. Originality/value This work demonstrated that GaN-based UV photodetector can be fabricated by using the GaN thin film grown by low-cost and simple sol-gel spin coating method.

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