Optical Constants of Zinc Selenide in Visible and Infrared Spectral Ranges

2017 ◽  
Vol 84 (4) ◽  
pp. 679-682 ◽  
Author(s):  
H. Qi ◽  
X. Zhang ◽  
M. Jiang ◽  
Q. Wang ◽  
D. Li
Keyword(s):  
Zinc Selenide ◽  
Optical Constants ◽  
Infrared Spectral ◽  
Spectral Ranges

scholarly journals Optical Constants of Chemical Vapor Deposited Graphene for Photonic Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1230
Author(s):  
Marwa A. El-Sayed ◽  
Georgy A. Ermolaev ◽  
Kirill V. Voronin ◽  
Roman I. Romanov ◽  
Gleb I. Tselikov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Constants ◽  
Near Infrared ◽  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Multilayer Graphene ◽  
Practical Applications ◽  
Chemical Vapor Deposited ◽  
Infrared Spectral ◽  
Spectral Ranges

Graphene is a promising building block material for developing novel photonic and optoelectronic devices. Here, we report a comprehensive experimental study of chemical-vapor deposited (CVD) monolayer graphene’s optical properties on three different substrates for ultraviolet, visible, and near-infrared spectral ranges (from 240 to 1000 nm). Importantly, our ellipsometric measurements are free from the assumptions of additional nanometer-thick layers of water or other media. This issue is critical for practical applications since otherwise, these additional layers must be included in the design models of various graphene photonic, plasmonic, and optoelectronic devices. We observe a slight difference (not exceeding 5%) in the optical constants of graphene on different substrates. Further, the optical constants reported here are very close to those of graphite, which hints on their applicability to multilayer graphene structures. This work provides reliable data on monolayer graphene’s optical properties, which should be useful for modeling and designing photonic devices with graphene.

scholarly journals Integrated Optical Phased Arrays for Beam Forming and Steering

2021 ◽  
Vol 11 (9) ◽  
pp. 4017
Author(s):  
Yongjun Guo ◽  
Yuhao Guo ◽  
Chunshu Li ◽  
Hao Zhang ◽  
Xiaoyan Zhou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Phased Arrays ◽  
Mechanical Stability ◽  
Building Blocks ◽  
High Yield ◽  
Beam Forming ◽  
Integrated Optical ◽  
Optical Phased Arrays ◽  
Infrared Spectral ◽  
Spectral Ranges

Integrated optical phased arrays can be used for beam shaping and steering with a small footprint, lightweight, high mechanical stability, low price, and high-yield, benefiting from the mature CMOS-compatible fabrication. This paper reviews the development of integrated optical phased arrays in recent years. The principles, building blocks, and configurations of integrated optical phased arrays for beam forming and steering are presented. Various material platforms can be used to build integrated optical phased arrays, e.g., silicon photonics platforms, III/V platforms, and III–V/silicon hybrid platforms. Integrated optical phased arrays can be implemented in the visible, near-infrared, and mid-infrared spectral ranges. The main performance parameters, such as field of view, beamwidth, sidelobe suppression, modulation speed, power consumption, scalability, and so on, are discussed in detail. Some of the typical applications of integrated optical phased arrays, such as free-space communication, light detection and ranging, imaging, and biological sensing, are shown, with future perspectives provided at the end.

Application Of Systems With Total Internal Reflection At Novosibirsk Free Electron Laser For Spectroscopy In The Terahertz Range

2016 ◽  
Vol 11 (3) ◽  
pp. 72-82
Author(s):  
Vasily Gerasimov ◽  
Elvira Grigorieva ◽  
Boris Knyazev ◽  
Yuliya Choporova
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Quantum Cascade Lasers ◽  
Attenuated Total Reflection ◽  
Terahertz Range ◽  
Optical Systems ◽  
Early Diagnosis Of Cancer ◽  
Infrared Spectral ◽  
Atr Spectroscopy ◽  
Spectral Ranges

Attenuated total reflection (ATR) spectroscopy is widely used in the visible and infrared spectral ranges. Progress in the development of laboratory scale monochromatic sources of terahertz radiation, such as quantum cascade lasers, suggests that in the near future this kind of spectrometers will be widely spread in the terahertz range. For this reason, the development of ATR based methods and devices is highly relevant. In this paper, we discuss the features of the use of ATR spectroscopy in the terahertz range, and describe some of the optical systems, designed for experiments at the Novosibirsk free electron laser (NovoFEL). We show that in the terahertz range the ATR spectroscopy has a number of significant advantages over the absorption spectroscopy. As an example, we are discussing the possibility of using terahertz polarimetry to develop a method for early diagnosis of cancer via the detection of left-handed to right-handed polysaccharide enantiomers ratio. Spectra of selected polysaccharides were recorded with a standard Fourier spectrometer using developed by us an ATR unit. The possibility of studying the polarization characteristics of polysaccharides in aqueous solutions using spectrally selective polarimeter with the NovoFEL as a tunable radiation source was demonstrated.

Calculation of Spectral Optical Constants Using Combined Ellipsometric and Reflectance Methods for Smooth and Rough Bulk Samples

2021 ◽  
pp. 000370282110478
Author(s):  
Gilles Fortin
Keyword(s):  
Rough Surface ◽  
Optical Constants ◽  
Sample Surface ◽  
Infrared Region ◽  
Homogeneous Sample ◽  
Specular Reflectance ◽  
Scattering Effects ◽  
Spectral Ranges ◽  
Reflectance Measurements ◽  
Polarized Reflectance

Spectra of the optical constants n and k of a substance are often deduced from spectroscopic measurements, performed on a thick and homogeneous sample, and from a model used to simulate these measurements. Spectra obtained for n and k using the ellipsometric method generally produce polarized reflectance simulations in strong agreement with the experimental measurements, but they sometimes introduce significant discrepancies over limited spectral ranges, whereas spectra of n and k obtained with the single-angle reflectance method require a perfectly smooth sample surface to be viable. This paper presents an alternative method to calculate n and k. The method exploits both ellipsometric measurements and s-polarized specular reflectance measurements, and compensates for potential surface scattering effects with the introduction of a specularity factor. It is applicable to bulk samples having either a smooth or a rough surface. It provides spectral optical constants that are consistent with s-polarized reflectance measurements. Demonstrations are performed in the infrared region using a glass slide (smooth surface) and a pellet of compressed ammonium sulfate powder (rough surface).

scholarly journals Can downwelling far-infrared radiances over Antarctica be estimated from mid-infrared information?

2019 ◽  
Vol 19 (11) ◽  
pp. 7927-7937
Author(s):  
Christophe Bellisario ◽  
Helen E. Brindley ◽  
Simon F. B. Tett ◽  
Rolando Rizzi ◽  
Gianluca Di Natale ◽  
...  
Keyword(s):  
Climate Models ◽  
Far Infrared ◽  
Mid Infrared ◽  
Spectral Bands ◽  
Noise Characteristics ◽  
Infrared Spectral ◽  
Infrared Radiances ◽  
Spectrally Resolved ◽  
Spectral Ranges ◽  
The Impact

Abstract. Far-infrared (FIR: 100cm-1<wavenumber, ν<667 cm−1) radiation emitted by the Earth and its atmosphere plays a key role in the Earth's energy budget. However, because of a lack of spectrally resolved measurements, radiation schemes in climate models suffer from a lack of constraint across this spectral range. Exploiting a method developed to estimate upwelling far-infrared radiation from mid-infrared (MIR: 667cm-1<ν<1400 cm−1) observations, we explore the possibility of inferring zenith FIR downwelling radiances in zenith-looking observation geometry, focusing on clear-sky conditions in Antarctica. The methodology selects a MIR predictor wavenumber for each FIR wavenumber based on the maximum correlation seen between the different spectral ranges. Observations from the REFIR-PAD instrument (Radiation Explorer in the Far Infrared – Prototype for Application and Development) and high-resolution radiance simulations generated from co-located radio soundings are used to develop and assess the method. We highlight the impact of noise on the correlation between MIR and FIR radiances by comparing the observational and theoretical cases. Using the observed values in isolation, between 150 and 360 cm−1, differences between the “true” and “extended” radiances are less than 5 %. However, in spectral bands of low signal, between 360 and 667 cm−1, the impact of instrument noise is strong and increases the differences seen. When the extension of the observed spectra is performed using regression coefficients based on noise-free radiative transfer simulations the results show strong biases, exceeding 100 % where the signal is low. These biases are reduced to just a few percent if the noise in the observations is accounted for in the simulation procedure. Our results imply that while it is feasible to use this type of approach to extend mid-infrared spectral measurements to the far-infrared, the quality of the extension will be strongly dependent on the noise characteristics of the observations. A good knowledge of the atmospheric state associated with the measurements is also required in order to build a representative regression model.

Three-dimensional silicon-based nanostructures in opal matrix: Preparation and properties

2000 ◽  
Vol 638 ◽  
Author(s):  
A.B. Pevtsov ◽  
V.G. Golubev ◽  
V.A. Kosobukin ◽  
D.A. Kurdyukov ◽  
A.V. Medvedev
Keyword(s):  
Near Infrared ◽  
Photonic Band Gap ◽  
Three Dimensional ◽  
Opal Matrix ◽  
Variable Extent ◽  
Infrared Spectral ◽  
Spectral Ranges ◽  
Silicon Based ◽  
Photonic Band ◽  
Matrix Preparation

AbstractThree-dimensional opal-silicon composites with both direct (a variable extent of filling of opal voids with silicon) and inverted structures have been synthesized. A structural analysis of these fabricated systems is performed. Reflectance spectra from the (111) surface of the composites are measured within the spectral range 400-900 nm. Observed spectral features are interpreted as a manifestation of the [111] direction photonic band gap that is tunable in position and width in the visible and near-infrared spectral ranges.

scholarly journals Ellipsometric Study of the Zinc Selenide Natural Cleaves Oxidation

2015 ◽  
Vol 16 (3) ◽  
pp. 481-486
Author(s):  
V. А. Оdarych
Keyword(s):  
Zinc Selenide ◽  
Optical Constants ◽  
Index Of Refraction ◽  
Atmospheric Conditions ◽  
External Layer ◽  
Second Stage ◽  
Transparent Layer ◽  
Ellipsometric Study ◽  
One Year ◽  
Two Stages

Measuring of ellipsometric parameters of the light reflected from the fresh cleaves surface of zinc selenide  are conducted under atmospheric conditions during one year. It has been found that the process of cleaves surface interaction with air consists of two stages. A layer with  thickness to 7 nm is formed on the first stage within  to 3 weeks. This layer optical constants  are a little less than zinc selenide optical constants. An external transparent layer with the index of refraction approximately 1,4 and thickness to 2,5 nm show itself on the second stage from one month of to year. Supposed, this external layer contains the mixture of an unstable oxides and air.

scholarly journals An optical system for remote sensing in the UV, visible, and NIR spectral ranges

2020 ◽  
Vol 44 (2) ◽  
pp. 195-202
Author(s):  
V.M. Vladimirov ◽  
V.A. Yukseev ◽  
E.G. Lapukhin
Keyword(s):  
Remote Sensing ◽  
Optical System ◽  
Near Infrared ◽  
Ultra Violet ◽  
Field Of View ◽  
Structural Elements ◽  
Earth Remote Sensing ◽  
Infrared Spectral ◽  
Uv Visible ◽  
Spectral Ranges

In this work, we propose a high-resolution optical system for Earth remote sensing, operating at 200-3300-nm wavelengths and providing a 4º field of view. Parameters of the system's structural elements are calculated and presented. Dot charts of the spots of confusion for the center, intermediate zones, and the edge of the field are considered. Over most of the operating wavelengths, the optical system is shown to be diffraction-limited, which provides attaining the highest possible spatial resolution. This system is considered as a tool for monitoring of the Earth's surface and collection of information in the ultra-violet, visible and near infrared spectral ranges (200-3300 nanometers).

scholarly journals Results of MSU-GS Equipment Operation on the Elektro-L No. 3 Spacecraft and Prospects for its Further Development

2021 ◽  
Vol 8 (2) ◽  
pp. 20-26
Author(s):  
Yu. M. Gektin ◽  
◽  
R. V. Andreev ◽  
A. A. Zaytsev ◽  
◽  
...  
Keyword(s):  
Radiation Detectors ◽  
Passive System ◽  
Quality Of Information ◽  
Equipment Operation ◽  
The Earth ◽  
Infrared Spectral ◽  
Spectral Ranges ◽  
Further Development ◽  
Radiation Cooling

The paper is devoted to the description of the technical evolution of the MSU-GS equipment installed on spacecraft of the Elektro-L series. The MSU-GS equipment is designed for imaging the Earth from a geostationary orbit in the visible and infrared spectral ranges with a resolution of 1 to 4 km at intervals of up to 15 minutes. The problems identified during the operation of the equipment on the Elektro-L No. 2 spacecraft are described. The main problem was the insufficient cooling of infrared photodetectors. The operation of the passive system for radiation cooling of infrared radiation detectors is described in detail. The modernization of this system made it possible to reach the required photodetector temperature values on the Elektro-L No. 3 spacecraft. The main results of MSU-GS operation on the Elektro-L No. 3 spacecraft are presented. The modernization of the equipment made it possible to significantly improve the quality of information from infrared channels in comparison with the Elektro-L No. 2 spacecraft. Much attention is paid to assessing the possibility of improving the scanning efficiency. Possible future upgrades of the MSU-GS equipment and the Elektro-L series spacecraft can improve the full Earth disk coverage characteristic to up to 5 minutes, which exceeds the characteristics of best foreign counterparts.

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