scholarly journals Characterization of CMP Slurries Using Densitometry and Refractive Index Measurements

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 542 ◽  
Author(s):  
Leticia Vazquez Bengochea ◽  
Yasa Sampurno ◽  
Marcus Kavaljer ◽  
Rob Johnston ◽  
Ara Philipossian
Keyword(s):  
Refractive Index ◽  
Linear Correlation ◽  
Limit Of Detection ◽  
Water Concentration ◽  
Water Addition ◽  
Point Of Use ◽  
Slurry Composition ◽  
Approximate Limit

We investigated the possibility of employing refractive index (RI) measurements for inline incoming slurry control at the point of use (POU), as an alternative to the widespread densitometry method. As such, it became necessary to determine if RI could detect smaller changes in slurry composition and, therefore, provide a tighter control. Three industrially-relevant silica-based slurries, namely, Fujimi PL-7106, Klebosol 1501-50, and CMC W7801, were characterized using both densitometry and RI measurements. Initial solutions of the three slurries were prepared and increasingly small amounts of ultrapurified water (UPW) were added to study the change in slurry properties. Results showed that both density and RI decreased linearly with the addition of water for all three slurries, with the 1501-50 being the most sensitive to water addition. A linear correlation between the two properties was found, with R2 values that exceeded 0.95 in all cases. Furthermore, the approximate limit of detection of both metrology tools was estimated based on the slope of the fitting line and resolution. When compared to densitometry, RI was found to be the far superior method for detecting smaller changes in water concentration.

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

Preparation and Characterization of Polyvinylidene Fluoride/ZrO2-TiO2 Optical Film with Wide Band Gap and High Refractive Index

2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Polyvinylidene Fluoride ◽  
Wide Band ◽  
High Refractive Index ◽  
Wide Band Gap ◽  
Optical Film

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

scholarly journals Demonstration of a Polymer-Based Single Step Waveguide by 3D Printing Digital Light Processing Technology for Isopropanol Alcohol-Concentration Sensor

2021 ◽  
Author(s):  
Kankan Swargiary ◽  
Romuald Jolivot ◽  
Waleed Soliman Mohammed
Keyword(s):  
Refractive Index ◽  
3D Printing ◽  
Limit Of Detection ◽  
Optical Power ◽  
Alcohol Concentration ◽  
Single Step ◽  
Gap Size ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
The Core

AbstractA polymer based horizontal single step waveguide for the sensing of alcohol is developed and analyzed. The waveguide is fabricated by 3-dimensional (3D) printing digital light processing (DLP) technology using monocure 3D rapid ultraviolet (UV) clear resin with a refractive index of n = 1.50. The fabricated waveguide is a one-piece tower shaped ridge structure. It is designed to achieve the maximum light confinement at the core by reducing the effective refractive index around the cladding region. With the surface roughness generated from the 3D printing DLP technology, various waveguides with different gap sizes are printed. Comparison is done for the different gap waveguides to achieve the minimum feature gap size utilizing the light re-coupling principle and polymer swelling effect. This effect occurs due to the polymer-alcohol interaction that results in the diffusion of alcohol molecules inside the core of the waveguide, thus changing the waveguide from the leaky type (without alcohol) to the guided type (with alcohol). Using this principle, the analysis of alcohol concentration performing as a larger increase in the transmitted light intensity can be measured. In this work, the sensitivity of the system is also compared and analyzed for different waveguide gap sizes with different concentrations of isopropanol alcohol (IPA). A waveguide gap size of 300 µm gives the highest increase in the transmitted optical power of 65% when tested with 10 µL (500 ppm) concentration of IPA. Compared with all other gaps, it also displays faster response time (t = 5 seconds) for the optical power to change right after depositing IPA in the chamber. The measured limit of detection (LOD) achieved for 300 µm is 0.366 µL. In addition, the fabricated waveguide gap of 300 µm successfully demonstrates the sensing limit of IPA concentration below 400 ppm which is considered as an exposure limit by “National Institute for Occupational Safety and Health”. All the mechanical mount and the alignments are done by 3D printing fused deposition method (FDM).

Development of an Optical Fiber Sensor with a D-shaped Fiber Bragg Grating Integrated in a Loop-mirror Optical Fiber Laser as a High Sensitivity Refractometer

2021 ◽  
Vol 32 ◽  
Author(s):  
Binh Pham Thanh ◽  
Thuy Van Nguyen ◽  
Van Hoi Pham ◽  
Huy Bui ◽  
Thi Hong Cam Hoang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Fiber ◽  
Fiber Laser ◽  
Fiber Bragg Grating ◽  
Limit Of Detection ◽  
Optical Fiber Sensor ◽  
High Sensitivity ◽  
Optical Signal ◽  
Bragg Grating ◽  
Loop Mirror

In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.

Highly sensitive refractive index sensor for detection of Hg2+ based on Fano-like resonance in metal-dielectric-metal meta-structure

2021 ◽  
Author(s):  
Shuangxiu Yuan ◽  
Xuebo Sun ◽  
Jing Li ◽  
Yan Li ◽  
Fufang Su ◽  
...  
Keyword(s):  
Refractive Index ◽  
Limit Of Detection ◽  
Wavelength Shift ◽  
Refractive Index Sensor ◽  
Large Area ◽  
Amount Of Substance ◽  
Resonance Modes ◽  
Dipole Resonance ◽  
Highly Sensitive ◽  
Fabry Perot

Abstract We experimentally and theoretically investigate Fano-like resonance in large-area Au/SiO2/Au nano-patches meta-structure, which is originating from the coupling between Fabry Perot resonance and magnetic dipole resonance modes. A highly sensitive refractive index sensor based on the lineshape analysis is obtained. The extracted wavelength shift with the amount of substance of Hg2+ changing from 10-3 pmol to 1 nmol has a linear dependence, and the sensitivity can reach to ultra-low limit of detection (LOD) as 10-3 pmol. This study may provide an approach for the development and modification in sensing.

scholarly journals Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

2017 ◽  
Vol 8 ◽  
pp. 2492-2503 ◽  
Author(s):  
Somi Kang ◽  
Sean E Lehman ◽  
Matthew V Schulmerich ◽  
An-Phong Le ◽  
Tae-woo Lee ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Refractive Index ◽  
Electric Fields ◽  
Surface Enhanced Raman Spectroscopy ◽  
Plasmonic Crystals ◽  
Metal Thickness ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Difference Time

Herein we describe the fabrication and characterization of Ag and Au bimetallic plasmonic crystals as a system that exhibits improved capabilities for quantitative, bulk refractive index (RI) sensing and surface-enhanced Raman spectroscopy (SERS) as compared to monometallic plasmonic crystals of similar form. The sensing optics, which are bimetallic plasmonic crystals consisting of sequential nanoscale layers of Ag coated by Au, are chemically stable and useful for quantitative, multispectral, refractive index and spectroscopic chemical sensing. Compared to previously reported homometallic devices, the results presented herein illustrate improvements in performance that stem from the distinctive plasmonic features and strong localized electric fields produced by the Ag and Au layers, which are optimized in terms of metal thickness and geometric features. Finite-difference time-domain (FDTD) simulations theoretically verify the nature of the multimode plasmonic resonances generated by the devices and allow for a better understanding of the enhancements in multispectral refractive index and SERS-based sensing. Taken together, these results demonstrate a robust and potentially useful new platform for chemical/spectroscopic sensing.

scholarly journals Refractive index and temperature sensitivity characterization of excessively tilted fiber grating

2017 ◽  
Vol 25 (4) ◽  
pp. 3336 ◽  
Author(s):  
Z. Yan ◽  
Q. Sun ◽  
C. Wang ◽  
Z. Sun ◽  
C. Mou ◽  
...  
Keyword(s):  
Refractive Index ◽  
Temperature Sensitivity ◽  
Fiber Grating

scholarly journals LC-MS characterization of acid degradation products of metoclopramide: Development and validation of a stability-indicating RP-HPLC method

2020 ◽  
Vol 11 (1) ◽  
pp. 781-789
Author(s):  
Sriram Valavala ◽  
Nareshvarma Seelam ◽  
Subbaiah Tondepu ◽  
Suresh Kandagatla
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Stability Indicating ◽  
Rp Hplc ◽  
Hplc Technique

The present study aims to develop a simple, accurate and specific stability-indicating RP-HPLC technique for the analysis of metoclopramide in the presence of its stress degradation products and characterization of degradation compounds by LC-MS/MS analysis. As per ICH Q1A-R2 guidelines, the drug was exposed to acid hydrolytic stress condition. Three degradation products were formed for MCP in acid hydrolysis. The liquid chromatography was processed on a Luna C18-(2) 100A,250×4.6mm 5micron column using an isocratic mobile phase consisting of 0.1% formic acid in water-acetonitrile (20:80, v/v) by adjusting the mobile phase at 1 ml/min flow rate with wavelength detection at 273 nm. The developed procedure was applied to LC-MS/MS (liquid chromatography-tandem mass spectrometry) for the characterization of all the degradant components. Total new three degradation compounds were recognized and identified by LC-MS/MS. The developed RP-HPLC technique was validated as per the ICH Q2-R1 guidelines. Limit of detection and limit of quantification values of MCP were evaluated from the linearity graph and were found to be 5.23 µg/ml and 17.44 µg/ml. Accuracy study was established at 80.0, 100.0 and 120.0 µg/ml concentration levels and the findings were found in the range of 98.4% - 101.8%. The linearity of the technique was assessed over the drug concentration range of 50.0 µg/ml to 250.0 µg/ml and the regression equation, slope and correlation coefficient values were found to be y = 10618x + 1623.2, 10618 and 0.9996 respectively. The developed technique was uninterruptedly applied for the quantification of metoclopramide inactive pharmaceuticals.

Sign in / Sign up

Export Citation Format

Share Document