Transmission Of Optical Radiation Research Articles

Enhanced optical and electrical properties of Nb-doped TiO2 thin films synthesized by atomic layer deposition using the supercycle strategy

Herein, we report highly transparent and conductive Nb-doped TiO2 thin films successfully grown by a thermal ALD process at 300 °C using titanium tetraisopropoxide, niobium(V) ethoxide, and water. The deposition was carried out by employing a supercycle approach, alternating cycles of Ti precursor followed by a monocycle of Nb precursor, thereby enabling precise control over the Nb dopant concentration. We demonstrate the crucial impact of the dopant concentration and annealing conditions played on the thickness, structure, morphology, composition, and optical and electrical properties of the resulting films. The incorporation of niobium dopants led to significant improvements in the film's characteristics. The Nb-doped TiO2 films exhibited an enhanced optical transmission efficiency up to 15 %, along with a remarkable reduction in resistivity by four orders of magnitude, reaching 10−3 Ω.cm, compared to undoped TiO2 films. These high performances establish Nb-doped TiO2 thin films as promising TCOs with wide-ranging applications in fields that require efficient current collection or injection in conjunction with optical radiation transmission.

Correction of multi-scale sunglint reflections from the water surface in airborne high-spatial resolution optical images.

Airborne optical images (AOI) are often with complex sunglint reflections, which brings a certain influence to watercolor retrieval. This includes the sunglint reflection with water surface statistical distribution characteristics caused by imaging viewing angles differences, with high spatial resolution surface discrete characteristics sharing similar viewing angles, and the surface Fresnel reflection sunglint differences caused by the skylight difference during the flight of unmanned aerial vehicles. Aiming at the multiscale optical characteristics of sunglint reflection in high spatial resolution AOI, based on multi-path optical radiation transmission, the sunglint reflection interference from three different imaging processes is clarified. We developed a correction method to eliminate these different sunglint reflections on water surfaces and improve the reflectivity accuracy. The comparison with the in situ measured remote sensing reflectance of water indicated that the root mean square error (RMSE) was reduced from 0.0009 sr-1 to 0.0004 sr-1, and the mean relative error (MRE) decreased from 21.8% to 15.7%. This method has also been applied to correct the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) images, showing good applicability. The method is fast, effective, and without auxiliary parameters, which provides a correction reference for different surface sunglint corrections of various AOI.

Transmission of Optical Radiation by a Polydisperse Ice Cloud

Transmission of Optical Radiation by a Polydisperse Ice Cloud

Dynamic Simulation on Canopy Light Distribution and Dry Matter Accumulation of Natural Colored Cotton in Alar Reclamation Area of Xinjiang

Based on Ross’s theory of optical radiation transmission and full consideration of influences of vertical distribution of canopy leaf area and leaf inclination angle distribution of colored cotton on the light distribution, the Gaussian 5-point distance was used to divide the canopy into 5 layers on basis of the leaf area index. The leaf inclination angle on each layer was divided into 6 equal parts by 15°. The types of radiation in canopy, spatial distribution of light radiation, as well as diurnal variation with solar hour angles were quantified in detail. After comprehensively considering influences of temperature, physiological age and other factors on photosynthesis and respiration, the canopy light distribution, photosynthetic production and dry matter accumulation of colored cotton were simulated with strong mechanistic and physiological & ecological significance. The colored cotton samples sown on April 16, 2019 were used to verify the model. The RMSEs of simulated and measured canopy PAR values at Beijing time 10:00, 12:00, 14:00 and 16:00 on July 30 were 58.2, 64.1, 43.4 and 39.7 µmol•m-2•s-1, respectively. The RMSE of simulated and observed values of the dry matter accumulation above ground was 412.6 kgDM•hm-2, reflecting the good predictability of the model.

In vitro spectroscopic investigation of human cataract lens capsule hydropermeability

The dynamics of collimated transmission of optical radiation in the wavelength range 1100-2000 nm during the in vitro dehydration of human cataract lens capsules in air was studied for the first time. For capsules separated from human cataract lenses the average value of the hydropermeability coefficient at dehydration was 0.19±0.10 µm/s. The average characteristic time of cataract lens capsules dehydration was 77±10 s for the samples studied.

Evaluation of the Level of Transmission of Solar Radiation by Eyeglasses (Spectacles) and its Effects on the Human Eye

Global atmospheric changes such as depletion of Ozone in the stratosphere and global warming contribute to the average increase of ultraviolet radiation on earth. Protective eyeglasses are normally recommended to safeguard the eyes from the harmful effects of solar radiation. In this paper, twenty (20) pairs of eyeglasses were selected based on systematic random sampling to determine the amount of optical radiation transmission and level of attenuation by eyeglasses, in the wavelength range of 200nm to 900nm using 6405 UV/VIS spectrophotometer. All the eyeglasses were found to transmit a substantial amount of ultraviolet radiation. The transmission of visible light depends on the lens colours. It was discovered that the eyeglasses do not provide complete protection from UV radiation. This shows that the glasses can still pose great danger to human eyes.

Hydrocarbon film formed on the surface of a semiconductor irradiated by an electron beam

The rate of formation of a hydrocarbon film on the surface of a sample subjected to the action of an electron beam is studied at room temperature and in cooling a sample to the liquid nitrogen temperature. The thickness and the optical radiation transmission of such films are measured as functions of the electron beam radiation time, the sample temperature, and the level of vacuum. The film thickness is measured with atomic force microscopy. The absorption of the films is determined by comparing the cathodoluminescence intensities from a pure sample surface and from the surface covered with a film. The experimental results can be used to estimate the film formation rate as a function of the sample temperature and the vacuum and to determine the optical radiation absorption at a wavelength of 300, 360, 550, and 665 nm.

Optical properties of composite thin films containing silver nanoparticles

Absorption and reflection of electromagnetic radiation by a composite thin film consisting of a transparent dielectric matrix with inclusions of metal nanoparticles of radius much less than the wavelength were theoretically investigated based on the Maxwell–Garnett model. The absorption, reflection, and transmission of optical radiation in such a dielectric composite film were analyzed using effective optical parameters for the refractive index and absorption coefficient that depended on the nanoparticle size.

Optical percolation in ceramics assisted by porous clusters

We investigated optical transparency in ceramics assisted by disordered porous clusters. The structure and statistical properties of three-dimensional (3D) well porous ceramics is studied. Theoretical model based on the percolation theory and numerical simulations are applied to interpret the observed phase transition from an optically opaque state to a transparent state. The porous ceramic samples were fabricated by the technique of slurry casting. The transmission of optical radiation (optical percolation) over the entire porous samples is observed since the critical concentration of porosity was exceeded. We explain this effect by the rising of the spanning cluster inside of the porous structure that produces a network of porous voids. Our experimental results are in good agreement with the numerical simulations.

Optimal algorithm for amplitude-phase control in adaptive-optics systems and estimate of its quality

The problem of controlling the transmission of optical radiation through a randomly inhomogeneous medium is investigated for the case in which complete a priori information on the statistical properties of the propagation channel is available. An optimal control algorithm is found for adaptive-optics systems for an arbitrary ratio of the observation time interval to the coherence time of the propagation channel. Both cw and pulsed probe regimes are discussed. An estimate is obtained for the efficiency of this optimal algorithm for the steady adaptation state.

The transmission of optical radiation through human nails

SUMMARY The transmission of optical radiation in the wavelength range 300–600 nm through thirteen human toenails obtained at autopsy was examined. The total transmitted radiation at fifteen different wavelengths was measured using an irradiation monochromator in conjunction with an integrating sphere and photodiode. A correction was included for fluorescence radiation from the nails. The nails exhibited decreasing transmission of optical radiation in the wavelength region 600–300 nm. These findings may be helpful in the understanding of photo-onycholytic reactions and in the design of suitable regimens for the treatment of psoriatic nail changes.

Low loss metallic waveguide for transmission of optical radiation

It is shown that a significant reduction of losses for transmission of optical radiation in a hollow metallic waveguide can be achieved by a proper dielectric coating of its walls. We solve and discuss the mode structure of a rectangular waveguide with two coated walls. An estimation of the losses in the metal walls and the dielectric coating is given. For short wavelengths (λ<10 μ) losses occur mainly in the metal wall, while for longer waveguide length they occur mainly in the dielectric. An example shows that for λ=1 μ the losses are reduced from 53 db/m for an uncoated waveguide to 4×10−6 db/m for a coated one.

The transmission of optical radiation through human nails.

The transmission of optical radiation in the wavelength range 300-600 nm through thirteen human toenails obtained at autopsy was examined. The total transmitted radiation at fifteen different wavelengths was measured using an irradiation monochromator in conjunction with an integrating sphere and photodiode. A correction was included for fluorescence radiation from the nails. The nails exhibited decreasing transmission of optical radiation in the wavelength region 600-300 nm. These findings may be helpful in the understanding of photo-onycholytic reactions and in the design of suitable regimens for the treatment of psoriatic nail changes.

Transmission of optical radiation by sharp bends in fiber-optical waveguides

A theoretical and experimental investigation is reported of the behavior of optical radiation near single sharp bends in quartz multimode fiber-optical waveguides. The theory uses conformal mapping of complex-variable functions to transform a curved waveguide into a straight one. Allowance is made for spatial distortions of the electromagnetic fields at the bend. The experimental method uses the experimental observation that almost all (~ 80%) of the optical radiation which has escaped from the core into the cladding in the bend area, is returned to the core when the waveguide becomes straight again. The technique involves measuring the dependence of the optical radiation intensity at the exit from the bent waveguide on the variable refractive index of the external medium in which the bend is immersed. By using this technique, it is possible to determine experimentally the interval of the propagation constants of the cladding modes excited at the bend, the intensity of the residual radiation which does not leave the waveguide core for the given bend radius, and the critical bend radius for which all the core radiation escapes into the cladding in the bend area. The theory satisfactorily explains the results.