2:30pm - 2:45pmID: 141
/ TOM13 S05: 1
TOM 13 Advances and Applications of Optics and Photonics
Spectral scaling transformations of nonstationary light
Jyrki Laatikainen1, Matias Koivurova2, Jari Turunen1, Tero Setälä1, Ari T. Friberg1
1University of Eastern Finland, Finland; 2Tampere University, Finland
We present optical systems, which transform isodiffracting nonstationary beams into fields obeying either cross-spectral purity or spectral invariance. The designs are hybrid refractive-diffractive imaging systems, which are able to perform the desired transformations over a broad spectral bandwidth and irrespective of the state of spatial coherence of the input beam.
2:45pm - 3:00pmID: 206
/ TOM13 S05: 2
TOM 13 Advances and Applications of Optics and Photonics
Cross-spectral purity for nonstationary optical fields
Meilan Luo1,2, Jyrki Laatikainen1, Atri Halder1, Matias Koivurova3, Tero Setälä1, Jari Turunen1, Ari T. Friberg1
1University of Eastern Finland, Finland; 2Hunan Normal University, China; 3Tampere University, Finland
We derive an extended reduction formula for the time-integrated coherence function starting from the cross-spectral purity conditions for nonstationary optical fields. Two types of separable cross-spectral density functions that ensure cross-spectral purity are introduced and their implications are discussed.
3:00pm - 3:15pmID: 219
/ TOM13 S05: 3
TOM 13 Advances and Applications of Optics and Photonics
A φ-Shaped Bending-Optical Fiber Sensor for the Measurement of Radial variation in Cylindrical Structures
Victor Henrique Rodrigues Cardoso1,4, Paulo Caldas4,5, M. Thereza R. Giraldi2, Orlando Frazão3,4, João Weyl Costa1, José L. Santos3,4
1Federal University of Pará, Applied Electromagnetism Laboratory, Rua Augusto Corrêa, 01, 66075-110, Belém, Pará, Brazil; 2Military Institute of Engineering, Laboratory of Photonics, Praça Gen. Tibúrcio, 80,22290-270, Rio de Janeiro, Brazil; 3Department of Physics and Astronomy, Faculty of Sciences of University of Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal; 4nstitute for Systems and Computer Engineering, Technology and Science, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal; 5Polytechnic Institute of Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347, Viana do Castelo, Portugal
This work presents preliminary results of the $\phi$ -shaped sensor mounted on support designed by additive manufacturing (AM). This sensor is proposed and experimentally demonstrated to measure the radial variation of cylindrical structures. The sensor presents an easy fabrication. The support was developed to work using the principle of leverage. The sensing head is curled between two points so that the dimension associated with the macro bend is changed when there is a radial variation. The results indicate that the proposed sensor structure can monitor radial variation in applications such as pipelines and trees.
3:15pm - 3:30pmID: 114
/ TOM13 S05: 4
TOM 13 Advances and Applications of Optics and Photonics
How can asphalt mixtures be smart?
Iran Rocha Segundo1,2, Salmon Landi Jr.3, Cátia Afonso2, Orlando Lima Jr.1, Elisabete Freitas1, Verônica Castelo Branco4, Manuel Filipe Costa5, Joaquim Carneiro2
1ISISE, Department of Civil Engineering, University of Minho, Azurém Campus, Guimarães, Portugal; 2Centre of Physics of Minho and Porto Universities (CF-UM-UP), University of Minho, Azurém Campus, Guimarães, Portugal; 3Federal Institute of Education, Science and Technology Goiano, Rio Verde – GO, Brazil; 4Transportation Engineering Department, Federal University of Ceará, Fortaleza, Brazil; 5Centre of Physics of Minho and Porto Universities (CF-UM-UP), University of Minho, Gualtar Campus, Braga, Portugal
The functionalization of asphalt mixtures is carried out in order to provide new capabilities to the road pavements, with major social, environmental and financial benefits. Optical characterization techniques as well as optical processes like photocatalysis play a major role in the development of new asphalt mixtures with smart functions. These advanced capabilities which are being developed in asphalt mixtures are: photocatalytic, superhydrophobic, self-cleaning, de-icing/anti-ice, self-healing, thermochromic, and latent heat thermal energy storage. The main objective of this research work is to stress the importance of optics and photonics technologies giving an overview of advanced functionalized smart asphalt mixtures.
3:30pm - 3:45pmID: 399
/ TOM13 S05: 5
Post Deadline submission
Padé resummation of divergent Born series and its motivation by analysis of poles
Thomas van der Sijs, Omar El Gawhary, Paul Urbach
Delft University of Technology, Faculty of Applied Sciences, Optics Research Group, Delft, The Netherlands
The Born series is in principle a powerful way to solve electromagnetic scattering problems.
Higher-order terms can be computed recurrently until the desired accuracy is obtained. In practice, however, the series solution often diverges, which severely limits its use. We discuss how Padé approximation can be applied to the Born series to tame its divergence. We apply it to the scalar problem of scattering by a cylinder, which has an analytical solution that we use for comparison. Furthermore, we improve our understanding of the divergence problem by analyzing the poles in the analytical solution. This helps build the case for the use of Padé approximation in electromagnetic scattering problems. Additionally, the poles reveal the region of convergence of the Born series for this problem, which agrees with actual calculations of the Born series.
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