scholarly journals How the Optical Properties of Leaves Modify the Absorption and Scattering of Energy and Enhance Leaf Functionality

2020 ◽  
pp. 349-384 ◽  
Author(s):  
Susan L. Ustin ◽  
Stéphane Jacquemoud
Keyword(s):  
Optical Properties ◽  
Infrared Spectrum ◽  
Related Species ◽  
Spectral Properties ◽  
Near Infrared ◽  
Solar Spectrum ◽  
Cellular Organization ◽  
Seed Plant ◽  
Or Groups ◽  
Shortwave Infrared

AbstractLeaves absorb, scatter, and transmit sunlight at all wavelengths across the visible, near-infrared, and shortwave-infrared spectrum. The optical properties of a leaf are determined by its biochemical and biophysical characteristics, including its 3-D cellular organization. The absorption and scattering properties of leaves together create the shape of their reflectance spectra. Terrestrial seed plant species share similar physiological and metabolic processes for fluxes of gases (CO2, O2, H2O), nutrients, and energy, while differences are primarily consequences of how these properties are distributed and their physical structures. Related species generally share biochemical and biophysical traits, and their optical properties are also similar, providing a mechanism for identification. However, it is often the minor differences in spectral properties throughout the wavelengths of the solar spectrum that define a species or groups of related species. This chapter provides a review and summary of the most common interactions between leaf properties and light and the physical processes that regulate the outcomes of these interactions.

Syntheses and Spectral Properties of Tetra-(4,4-Dimethyl-Phenyl) Dithiolene Nickel Complex

2013 ◽  
Vol 469 ◽  
pp. 81-86
Author(s):  
Xue Hua Cheng ◽  
Xiu Lan Xin ◽  
Li Hua Yin ◽  
Yang Yu
Keyword(s):  
Thermal Stability ◽  
Melting Point ◽  
Infrared Spectrum ◽  
Spectral Properties ◽  
Nickel Complex ◽  
Near Infrared ◽  
Nickel Complexes ◽  
Raw Material ◽  
Synthesis Time ◽  
Photo Stability

Tetra-(4,4-dimethyl-phenyl) dithiolene nickel complex was synthesized by sulfuration with P2S5 and nickel complexs using bis-(4,4-dimethyl-phenyl) ethanedione as raw material. The structure of dithiolene nickel complexes was characterized by melting point, IR and 1HNMR. The maximum absorption spectra of this dithiolene nickel complexes in different solvent was measured by Ultraviolet-Visible-near Infrared Spectrum, and the photo stability and thermal stability were discussed. The results showed that this new method was used to synthesis bis-(4,4-dimethyl-phenyl) ethanedione, which greatly reduces the synthesis time compared to previous methods.

scholarly journals Ground Reflectance Retrieval on Horizontal and Inclined Terrains Using the Software Package REFLECT

2018 ◽  
Vol 10 (10) ◽  
pp. 1638
Author(s):  
Yacine Bouroubi ◽  
Wided Batita ◽  
François Cavayas ◽  
Nicolas Tremblay
Keyword(s):  
Optical Properties ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Software Package ◽  
Near Infrared ◽  
Solar Spectrum ◽  
Sensor Calibration ◽  
Topographic Effects ◽  
Atmospheric Conditions ◽  
Spectral Bands

This paper presents the software package REFLECT for the retrieval of ground reflectance from high and very-high resolution multispectral satellite images. The computation of atmospheric parameters is based on the 6S (Second Simulation of the Satellite Signal in the Solar Spectrum) routines. Aerosol optical properties are calculated using the OPAC (Optical Properties of Aerosols and Clouds) model, while aerosol optical depth is estimated using the dark target method. A new approach is proposed for adjacency effect correction. Topographic effects were also taken into account, and a new model was developed for forest canopies. Validation has shown that ground reflectance estimation with REFLECT is performed with an accuracy of approximately ±0.01 in reflectance units (for the visible, near-infrared, and mid-infrared spectral bands), even for surfaces with varying topography. The validation of the software was performed through many tests. These tests involve the correction of the effects that are associated with sensor calibration, irradiance, and viewing conditions, atmospheric conditions (aerosol optical depth AOD and water vapour), adjacency, and topographic conditions.

Near Infrared Spectroscopy

1998 ◽  
Vol 6 (1) ◽  
pp. 3-17 ◽  
Author(s):  
L. Bokobza
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectrum ◽  
Near Infrared Spectroscopy ◽  
Spectral Properties ◽  
Near Infrared ◽  
High Energy ◽  
Local Mode ◽  
Mode Effects ◽  
Vibrational Anharmonicity ◽  
Frequency Intensity

Some of the concepts that make a near infrared spectrum understandable are reviewed. The origin of vibrational anharmonicity which determines the occurrence and the spectral properties (frequency, intensity) is discussed. The importance of the effects of the resonances which increase with increasing excitation are mentioned. Some of the characteristics of high energy overtone/combination spectra are considered in relation to local mode effects. The location of some particular group frequencies is provided.

Measurement of soot optical properties in the near-infrared spectrum

2000 ◽  
Vol 43 (18) ◽  
pp. 3299-3303 ◽  
Author(s):  
Jinyu Zhu ◽  
Mun Young Choi ◽  
George W. Mulholland ◽  
Louis A Gritzo
Keyword(s):  
Optical Properties ◽  
Infrared Spectrum ◽  
Near Infrared ◽  
Near Infrared Spectrum

scholarly journals Synthesis and Spectral Properties of 6'-Triazolyl-Dihydroxanthene-Hemicyanine Fused Near-Infrared Dyes

2020 ◽  
Author(s):  
Gu Lingyue ◽  
Kévin RENAULT ◽  
Anthony ROMIEU ◽  
Jean-Alexandre RICHARD ◽  
Rajavel Srinivasan
Keyword(s):  
Optical Properties ◽  
Spectral Properties ◽  
Molecular Diversity ◽  
Near Infrared ◽  
Click Reaction ◽  
Fine Tuning ◽  
Active Materials ◽  
Hybrid Scaffold ◽  
Physiological Conditions ◽  
Phosphate Buffered Saline

We describe the synthesis of a range of 6’-triazolyl-dihydroxanthene-hemicyanine (DHX-hemicyanine) fused dyes through an effective copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction, with the dual aim of providing molecular diversity and fine tuning spectral properties of these near-infrared (NIR)-active materials. This was implemented by reacting 16 different aliphatic and aromatic azides with a terminal alkynyl-based-DHX-hemicyanine hybrid scaffold prepared in four steps and 35% overall yield from 4-bromosalicylaldehyde. The resulting triazole derivatives have been fully characterized and their optical properties determined both in organic solvents and simulated physiological conditions (phosphate buffered saline containing 5% of bovine serum albumin protein). This systematic study is a first important step towards the development of NIR-I fluorogenic "click-on" dyes or related photoactive agents for light-based diagnostic and/or therapeutic applications.

Influence of Three-Component Barrier Layers on Optical Properties of Photodetectors with Quantum Dots

2021 ◽  
Vol 316 ◽  
pp. 999-1003
Author(s):  
Eduard E. Blokhin ◽  
Vladimir A. Irkha ◽  
Alexandr S. Pashchenko
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Solar Energy ◽  
Infrared Spectrum ◽  
Solid Solutions ◽  
Dark Current ◽  
Near Infrared ◽  
Inas Quantum Dots ◽  
Barrier Layers ◽  
Thin Barrier

The results of the presented studies demonstrate the possibility of using two and three component solid solutions, based on elements of the A3B5 groups, as thin barrier layers to cover an array of structured InAs quantum dots for photoactive heterointerfaces of solar energy. When using three-component solid solutions for QD barrier layers, a decrease in the thermionic generation in the near infrared spectrum and a decrease in the dark current of the heterointerface are obtained.

scholarly journals Synthesis and Spectral Properties of 6'-Triazolyl-Dihydroxanthene-Hemicyanine Fused Near-Infrared Dyes

2020 ◽  
Author(s):  
Gu Lingyue ◽  
Kévin RENAULT ◽  
Anthony ROMIEU ◽  
Jean-Alexandre RICHARD ◽  
Rajavel Srinivasan
Keyword(s):  
Optical Properties ◽  
Spectral Properties ◽  
Molecular Diversity ◽  
Near Infrared ◽  
Click Reaction ◽  
Fine Tuning ◽  
Active Materials ◽  
Hybrid Scaffold ◽  
Physiological Conditions ◽  
Phosphate Buffered Saline

We describe the synthesis of a range of 6’-triazolyl-dihydroxanthene-hemicyanine (DHX-hemicyanine) fused dyes through an effective copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction, with the dual aim of providing molecular diversity and fine tuning spectral properties of these near-infrared (NIR)-active materials. This was implemented by reacting 16 different aliphatic and aromatic azides with a terminal alkynyl-based-DHX-hemicyanine hybrid scaffold prepared in four steps and 35% overall yield from 4-bromosalicylaldehyde. The resulting triazole derivatives have been fully characterized and their optical properties determined both in organic solvents and simulated physiological conditions (phosphate buffered saline containing 5% of bovine serum albumin protein). This systematic study is a first important step towards the development of NIR-I fluorogenic "click-on" dyes or related photoactive agents for light-based diagnostic and/or therapeutic applications.

Two-Dimensional Near-Infrared and Shortwave Infrared Molecular Aggregates: Taking Kasha’s Model to the Next Dimension

2019 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Danielle Koppel ◽  
Chern Chuang ◽  
Danielle Cadena ◽  
Jianshu Cao ◽  
...  
Keyword(s):  
Near Infrared ◽  
Photophysical Properties ◽  
Satellite Telemetry ◽  
Transition Dipole Moment ◽  
Short Wave ◽  
Tissue Imaging ◽  
Transition Dipole ◽  
Deep Tissue Imaging ◽  
Excitonic States ◽  
Shortwave Infrared

Technologies which utilize near-infrared (700 – 1000 nm) and short-wave infrared (1000 – 2000 nm) electromagnetic radiation have applications in deep-tissue imaging, telecommunications and satellite telemetry due to low scattering and decreased background signal in this spectral region. However, there are few molecular species, which absorb efficiently beyond 1000 nm. Transition dipole moment coupling (e.g. J-aggregation) allows for redshifted excitonic states and provides a pathway to highly absorptive electronic states in the infrared. We present aggregates of two cyanine dyes whose absorption peaks redshift dramatically upon aggregation in water from ~ 800 nm to 1000 nm and 1050 nm with sheet-like morphologies and high molar absorptivities (e ~ 10<sup>5 </sup>M<sup>-1</sup>cm<sup>-1</sup>). To describe this phenomenology, we extend Kasha’s model for J- and H-aggregation to describe the excitonic states of <i> 2-dimensional aggregates</i> whose slip is controlled by steric hindrance in the assembled structure. A consequence of the increased dimensionality is the phenomenon of an <i>intermediate </i>“I-aggregate”, one which redshifts yet displays spectral signatures of band-edge dark states akin to an H-aggregate. We distinguish between H-, I- and J-aggregates by showing the relative position of the bright (absorptive) state within the density of states using temperature dependent spectroscopy. Our results can be used to better design chromophores with predictable and tunable aggregation with new photophysical properties.

Sign in / Sign up

Export Citation Format

Share Document