A sky radiance distribution model developed by Brunger and Hooper (1993) has been applied to CASI IncidentLight Sensor data in order to estimate the downwelling solar irradiance at the aircraft. Continuous slope changes of the ILS sensor due to variations of the aircraft attitude is a problem in the direct use of the ILS data, but this helps in finding optimum coefficients for the model. The model results a unique set of coefficients for each flightline, which relates to the parameterised atmospheric condition. Radiance distributions at sensor level for different flightlines characterise different atmospheric conditions. Distributions of radiance depend upon the sun position and atmospheric turbidity but the angular distribution remains generally characteristic of single scattering (Shepherd and Xu, 1993).
Physically-based rendering (PBR) is a technique in which the light transport in a virtual scene is calculated to resemble the interaction of light in a real-world scene as accurately as possible [Pharr et al., 2016]. High-fidelity inputs and physically-based rendering are the key components of a photorealistic render. In general, there are two types of inputs i.e. (i) a mathematical model of 3D geometry with the material properties of the object/scene to render and (ii) a high-fidelity lighting information of the environment. Advanced 3D modeling softwares, such as Maya, 3DS Max, Blender, etc. can produce very accurate 3D models of objects. Moreover, there are existing methods [Levoy et al., 2000; Rusinkiewicz et al., 2002; Izadi et al., 2011] that can “scan” real objects to obtain its 3D geometry and material properties such as colour and light reflectivity with reasonable accuracy. On the other hand, there are several techniques such as Image Based Lighting (IBL) [Debevec, 2002], Lumigraph [Gortler et al., 1996], and IncidentLight Fields (ILF) [Unger et al., 2003] that can capture and represent the real-world light in an environment with varying degrees of dimensionality and capabilities. The work described in this thesis will focus on the real-world light information inputs.
Visual information is important in the field of robotics to assist object recognition and route mapping. However, variations of lighting fixtures impede the generalization for indoor illumination and therefore require image correction. Hence, the project will analyze on the effect of different white light illumination which produce different reflection on captured image using industrial digital camera. Since most of the object on earth is inhomogeneous, this research mainly focused on samples of inhomogeneous object and studies the reflection characteristic. Three spherical objects painted with three different paints are the objects of study. To maintain the colour constancy of the object, the correction factor is obtained using MATLAB software to ensure the result of the colour image after processing is almost the same with the colour of benchmark image.
In this paper, Bragg gratings waveguide is proposed to investigate the behavior of diffraction efficiency at different wavelength and incident angle of light. SNR is also observed with the help of diffracted light and unwanted light. The electric field distribution over the proposed waveguide is improved with 1.55µm wavelength and 0 0 incident angle, respectively. It is also observed that the proposed waveguide provides better diffracted light with electric field distribution (1.969 v/m), output power (12 dB), DE (8%), SNR (25.5 dB) at 1.55µm wavelength and 0 0 incident angle, respectively. From the result, it can be conclude that the proposed design gave it best performance in x-ray diffraction.
The present investigation is carried out to study the scattering properties of RBC cells with different polarized laser light as individual scatterrers. As it is evident from litera- ture, RBC can form clusters or aggregates known as rouleuax. However, the present study is focused on single particle scattering from RBC which may be modeled as “disc shaped” particles. They can be studied as Mie scatterers. Nevertheless, the theory is formulated basically for spherical (larger) particles. RBC being discs can orient in many directions and to get insight into this phenomenon, we have plotted the polar plots. Polar plots with unpolarized, circular polarized and linear polarized incidentlight have been plotted. Scattered intensity Vs Angle shows similar angular variations for all pola- rization work.
ABSTRACT: Photodetectors are widely used in the optical communication at the transmission end of the photonic system which convert the incidentlight to current. So, it is needed to make photodetectors with high quantum efficiency for better detection of light and efficient working of the photonics system. Silicon based photodetectors are famous because of their low cost and it is easy to integrate with optoelectronic devices. However there are materials like InGaAs, GaAs and Ge based detectors which have large responsivity and low dark current. It is a challenging task to design detectors with high performance for optical communication system, so there is need for balance between absorption efficiency, wavelength ranges and cost which can be overcome with a particular designing of the detector. There is a need to study about the various parameters of the photodetectors and improve these parameters by modelling of Si based photodetectors, their compatibility with different materials. This paper tends to review all the types of detectors which are Si based and analysis if their characteristics.
Number of published work [10, 14] dealt with a highly selective method such as chmiluminescence, fluorescence using continuous flow injection system. The present work is concerned with the determination of Cobalt (II) ion with rubeanic acid (or dithio- oxamide) in alkaline solution of sodium hydroxide which in turn gives a black precipitate. The concentration of cobalt (II) ion is measured according to the attenuation of the dark particulate to incidentlight at two detecting flow cells that have the same input and output with a distance of 100 mm in between the two cells to allow either completion of reaction then followed by detection at the second detecting stage. Materials and Methods
The synergy idea indicates that improving the synergy between flow and light fields can markedly enhance the L/D cycle frequency with a lower increase in pump- ing costs, which is favorable for practical applications. We can obtain better synergy if the vortex core and L/D boundary are closer to each other and the vortex whose core is too far from the L/D boundary is removed. With such an idea, we can not only have a deeper understand- ing of some known numerical and experimental results about mixer addition but also develop useful rules to guide the design of mixers. The geometrical parameter design of a helical mixer is taken as an example to illus- trate the importance and feasibility of the synergy idea. By applying the method of relocating vortices closer to the L/D boundary, which is accomplished by reduc- ing the mixer’s radial height from the inner side, the L/D cycle frequency of the PBR is increased by up to 10.8% for incidentlight intensities ranging from 375 to 2400 μmol m −2 s −1 , and the pumping costs are simulta-
In recent years, MoS 2 has emerged as a prime material for photodetector as well as phototransistor applications. Usually, the higher density of state and relatively narrow bandgap of multi-layer MoS 2 give it an edge over monolayer MoS 2 for phototransistor applications. However, MoS 2 demonstrates thickness-dependent energy bandgap proper- ties, with multi-layer MoS 2 having indirect bandgap characteristics and therefore possess inferior optical properties. Herein, we investigate the electrical as well as optical properties of single-layer and multi-layer MoS 2 -based pho- totransistors and demonstrate improved optical properties of multi-layer MoS 2 phototransistor through the use of see-through metal electrode instead of the traditional global bottom gate or patterned local bottom gate structures. The see-through metal electrode utilized in this study shows transmittance of more than 70% under 532 nm vis- ible light, thereby allowing the incidentlight to reach the entire active area below the source and drain electrodes. The effect of contact electrodes on the MoS 2 phototransistors was investigated further by comparing the proposed electrode with conventional opaque electrodes and transparent IZO electrodes. A position-dependent photocurrent measurement was also carried out by locally illuminating the MoS 2 channel at different positions in order to gain better insight into the behavior of the photocurrent mechanism of the multi-layer MoS 2 phototransistor with the transparent metal. It was observed that more electrons are injected from the source when the beam is placed on the source side due to the reduced barrier height, giving rise to a significant enhancement of the photocurrent.
Light scattering is a very broad topic which has a scientiﬁc history of over a century . Generally speaking, light is scattered whenever it propagates in a material medium, because of its interaction with the molecules constituting the medium, which act as scattering centers. As a consequence, most of the light that we observe in daily life is scattered light. However, the arrangement of these molecules strongly determines the effectiveness of the scattering for a given input wave. For instance, in a perfect crystal the molecular scattering centra are so orderly arranged that the scattered output waves interfere destructively in such a way that only the propagation velocity of the incident wave is changed. Conversely, in a gas or a ﬂuid, the statistical ﬂuctuations of the molecular arrangement can cause signiﬁcant scatter- ing. Depending on the nature of the interaction processes, light can be scattered elastically or inelastically . In elastic (Rayleigh) scattering, the frequency of the scattered light is equiv- alent to that of the incidentlight. On the other hand, inelastic (Raman) scattering results in scattered light of different frequency than the incident. In this Thesis we will concentrate on elastic scattering processes where the frequency of the incidentlight is conserved. Addition- ally, we will restrict our analysis to linear scattering processes, where this linearity refers to the amplitude of the light ﬁeld. A scattering process can be consider linear when, for a sum of incident input waves, the scattered output wave is a linear superposition of the incident ones. Such linear processes can be described by a scattering matrix, which maps input and output waves. In this context, we take a broad deﬁnition of an elastic light scattering process; namely, any optical process that changes the direction of the wave-vector of the light. Thus a scattering process can range from Rayleigh scattering by a point particle to refraction by a lens.
Based on Mie scattering theory, the equivalent random scattering medium model was studied. The variation pattern was simulated from equivalent particle size, incidence Angle and equivalent refractive index distribution. The scattering and polarization characteristics at microscale were studied. In the process of outdoor quality detection in zaoyuan, the polarization state of reflected light is affected by incidentlight wavelength, incident direction, medium refractive index and reflection times. The s-component is reflected once on the surface. After the polarizing disc rotates by 90 degrees, it is reflected repeatedly on the inner surface after detecting it. In this paper, the intensity change simulation of S component and P component at different angles and wavelengths is carried out, and the results obtained by the multi-angle scattering and spectral ellipsometer are relatively consistent. The scattering polarization characteristic of jujube was verified by spectroellipsometer. The theoretical simulation results provide important reference for further carrying out multi-angle polarization scattering experiment and constructing polarization scattering model to improve the precision and stability of quality detection of jujube.
Another critical parameter is light intensity (quantity), whereby it varies with its position and time in the cultiva- tion process of microalgae (Huang et al. 2012) due to the nature of microalgae as an efficient light receiver. In lab scale experiment with small volume of culture and short light path, incidentlight intensity is commonly used as the light quantity parameter to determine the opti- mum condition (Wahidin et al. 2013; Teo et al. 2014b). However, in up-scale or large volume cultivation, mean light intensity is a better indication of light condition; light intensity at the illumination surface, IS and oppo- site surface, BS (end of light path) need to be considered (Ogbonna and Tanaka 2000). Light distribution inside the PBR is very important to ensure light energy to biomass conversion is at optimum condition.
This experiment looks to investigate the physical optics of the interference pattern called Newton’s rings and calculate the wavelengths of various filters as well as the radius of curvature of a plano-convex lens. Through the consideration of the wavelength dependence of the diameter of the rings, mathematical relationships are derived and applied on the measured data to verify the known wavelength values. The results produced by the data successfully show the relationship between diameters of the rings, their order, the refractive index of the medium causing the interference pattern and the wavelength of the incidentlight. Graphical analysis confirms that the diameters of the rings are larger at higher orders, and larger still for longer incident wavelengths .
Since a dielectric CPC may be used for combined application of daylighting and PV electricity generation (Yu et al., 2014a), the study of optical performance of dielectric CPC would be divided into two parts: the first one is optical efficiency, which is the ratio of received light on the base (onto which the solar cells are attached) of dielectric CPC to the incidentlight on the front aperture of dielectric CPC, this value is related to the function of local electricity generation; on the other hand, the transmittance, which stands for the ratio of transmitted light through dielectric CPC to the incidentlight on the front aperture of dielectric CPC is used to indicate the daylighting control ability. The hourly optical performance of the studied dielectric CPC-4 on 21 st April and 21 st
Since the transmissions of the appropriate NaD components depend on the polarization of the incidentlight and since the polari zation of the sensitized fluorescence is different from that of the resonance fluorescence (Gough, 1967), it was not possible to determine the transmission of the interference filters to D^ sensitized fluores cence. Thus, although T|^ could be measured directly, x\^ could not; nor could be obtained indirectly by the method outlined in the procedure for experiments with noble gases since all values would be smaller than 1 X 10 ^ in the experimental pressure range.
To investigate the SOP influences of the incidentlight on the spatial intensity distributions, especially the fo- cusing performance, the designed NRPL was illuminated by the linearly, circularly, azimuthally, and radially polar- ized light, respectively. All the cases were computed by the FDTD numerical simulations. According to the matrix optics, the different polarized lights can be de- scribed by the Jones matrix formalisms, and the corre- sponding matrix expression was applied to define the incidentlight. The boundary of the model was perfectly matched layer (PML) with a layer number of 12. To bal- ance the computational accuracy and the memory con- sumption in the simulations, the mesh size was set to be 10 nm in the output region and 5 nm around the focal region.
electrons on the graphene whereas it can interact with them in the (VV) polarization configuration, as shown in Figure 1b. In fact, only the projected component of the electric field vector of the incidentlight onto the graphene plane can effectively contribute to Raman scattering process as illustrated in Figure 1b. This is exactly the same situation as the polarized Raman scat- tering on single isolated CNT, where the Raman inten- sities of the G-band and the RBM of the CNT exhibited approximately cos 2 α-dependence in which α is the angle between the CNT axis and the polarization direction of the incidentlight . Thus, the normalized Raman intensities of the G-band and the 2D-band mea- sured in out-of-plane configuration with respect to that measured in in-plane configuration, I I o i ð Þ ð Þ θ θ ð Þ G and I I o i ð Þ ð Þ θ θ