PHOTOPTICS 2024 Abstracts

Area 1 - Lasers
Short Papers
Area 2 - Optics
Full Papers Short Papers
Area 3 - Photonics
Full Papers Short Papers

Area 1 - Lasers

Short Papers
Paper Nr: 8
Title:

Improving a Compressively Strained Ga x In 1-X N y As 1-Y /GaAs Multiple Quantum Well Lasers for Emitting around 1300 Nm
Authors:

F. Hadjaj, M. Belhadj, A. Nasri, I. Benyahia and K. Laoufi
Abstract: The objective of this work is to study the effect of Nitrogen incorporation on the structural and optical properties of GaxIn1-xNyAs1-y semiconductor alloy in order to obtain quantum well GaxIn1-xNyAs1-y/GaAs structures emitting at wavelengths around 1.3 μm. We also investigated their effect on the band gap energy, the electron effective mass, the optical gain, and the optical confinement. The incorporation of Nitrogen in the GaxIn1-xAs alloy gave very particular and attractive properties, the most important being the reduction of the band-gap energy and a significant increase in effective mass, which results in an increase in the emission wavelength. The anticrossing band model describes these properties. It is also found that the optical gain and confinement factor were found to be strongly increased when the Nitrogen content was reduced. In order to achieve a wavelength of 1.3 μm and maintain a high-quality structure, we found that decreasing the Gallium composition (x) and increasing the Nitrogen composition (y) simultaneously gave accurate results.
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Paper Nr: 24
Title:

Optimization of Active Region of Quantum Cascade Laser (QCL) by Coupled Calculation of Genetic Algorithm and QCL Simulator
Authors:

Shigeyuki Takagi, Tsutomu Kakuno, Rei Hashimoto, Kei Kaneko and Shinji Saito
Abstract: We applied a coupled calculation of genetic algorithm and a quantum cascade laser (QCL) simulator (nextnano.QCL) to calculate the gain that excites laser light in the active region of the QCL. The film thicknesses of the nine layers constituting the active region were changed simultaneously, and the film structure with the maximum gain was determined from 1000 type of film structures. The QCL simulator incorporating a non-equilibrium Green’s function was used to calculate the gain of the QCL, and the validity of the simulation was evaluated using the active region structure reported in the previous paper. In the coupled calculation of the QCL simulator and genetic algorithms, we used gain as an objective function and methods of crossing, natural selection, and mutation simulating the evolutionary process of living organisms to optimize the thickness of nine films. As a result of the optimization calculation, the optimized structure had gain (78.44 cm–1 ) higher than that (50.01 cm–1 ) in a structure reported in a previous paper.
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Area 2 - Optics

Full Papers
Paper Nr: 19
Title:

Developing a Sequential Mask Projection Technique for Micro-Lens Generation Using Excimer Laser Micro-Structuring
Authors:

Eric Syrbe, Sebastian Buettner, Michael Pfeifer and Steffen Weissmantel
Abstract: Fluorine laser micro-structuring enables the generation of micro-optics in glasses and other wide band gap materials. For the generation of micro-lenses, we developed a new micro-structuring method and the appropriate hardware. The process is based on the mask projection technique and uses a set of different circular masks, which are placed consecutively within the laser beam. This creates a ring-shaped ablation area with variable inner radius. By using an appropriate set of masks, it is possible to generate a surface with a defined spherical shape. The measured radii of curvature of the structured micro-lenses are in the range of 90 μm up to 250 μm with corresponding surface roughness values to below 100 nm. The entire process and requirements are described, and the results are presented.
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Paper Nr: 20
Title:

Improvement of Ghost Imaging-OCT High-Resolution Real-Time Imaging
Authors:

Decai Huyan and Tatsuo Shiina
Abstract: We previously proposed a novel system composed of GI (ghost imaging) and OCT (optical coherence tomography) to solve the problem of scattering and absorption by OCT measuring within scattering media. It is named GI-OCT. And we successfully obtained images of scattering media and target separately in a 2× 2mm. In this paper, we improve a new computational approach to deal with the significant computational demands arising from increased image resolution. Using DIP (deep image prior) technique, we obtained images with minimal measurement data compared to traditional computational methods. In the simulation, the number of measurements required to obtain a clear image was reduced to 10%.
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Short Papers
Paper Nr: 9
Title:

Biconic Approximation of a Toric Surface
Authors:

Wei-Jun Chen
Abstract: In this work, a toric surface is explicitly approximated by a biconic model by decomposing the toric surface into a biconic–identical component and other elliptical cylinder–related residual components. These residual components determine the zone– and the azimuthal orientation–dependent approximation accuracy. In addition to the analytical underpinning, a direct fit of the biconic model to a data set sampled from a toric surface is performed and consistent results are obtained.
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Paper Nr: 12
Title:

Machine Learning-Based Disease Severity Prediction in Sickle Cell Patients: Spectroscopic Insights
Authors:

Sumit K. Roy, Saurabh Gupta and Pankaj Jain
Abstract: Sickle cell disease (SCD) presents a significant health challenge with diverse clinical manifestations. Early and accurate prediction of the onset and severity of co-morbidities in SCD is vital for improving outcomes. In this study, we employ advanced healthcare informatics, and machine learning techniques to analyze longitudinal blood pathology data. By focusing on crucial hematological parameters, we gain valuable insights into SCD’s pathophysiology. Additionally, incorporating spectroscopic insights into the study unveils molecular details, enriching the understanding of the disease’s complexity and paving the way for more nuanced and targeted interventions. Utilizing this data, we construct predictive models enabling personalized interventions and advancing precision healthcare management. The research revealed that Random Forest outperforms other algorithms, achieving an accuracy of 88%, recall of 82%, and specificity of 92%. This robust evaluation underscores the model’s reliability in predicting both positive and negative instances. These findings offer a promising pathway for enhancing disease prediction, management, and treatment planning, providing invaluable guidance for clinical practice in the context of sickle cell disease.
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Paper Nr: 18
Title:

Optical Characterization of Micro Spiral Phase Plates
Authors:

Sebastian Buettner, Erik Thieme and Steffen Weissmantel
Abstract: The results of our investigations on laser fabricated micro spiral phase plates in fused silica are presented. Other than in previous investigations we focussed on the optical characterization of the SPPs. As we could show, the laser-based process enables the generation of spiral phase plates with different topological charges, handedness, modulation depths and level numbers. Each geometric property influences the property of a transmitting electro-magnetic field and therefore the orbital angular momentum. For the optical characterization we observed and analysed the diffraction images of the generated SPPs. Moreover, we validated our results by calculating the diffraction patterns under variation of certain parameters.
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Paper Nr: 21
Title:

OCT Image Analysis of Internal Changes in Leaves due to Ozone Stresses
Authors:

Hayate Goto, Nofel Lagrosas and Tatsuo Shiina
Abstract: Changes in environmental conditions can be evaluated by detecting the conditions in indicator plants. Indicator plants are sensitive to specific environmental stresses. This research focused on white clover as an indicator plant for ozone. To analyze the effects of weaker stresses, compact OCT (Optical coherence tomography) for plants was developed, which allows for non-invasive and non-contact cross-sectional imaging of white clover (Trifolium repens) leaves exposed to ozone gas. OCT image changes on each level of ozone damage were evaluated using parameters such as the OCT signal level of the leaf palisade layer, the thickness of the leaf palisade layer, and texture analysis using GLCM (Gray-Level Co-occurrence Matrix). Measurements of leaves grown in our laboratory showed increased palisade tissue signal, thicker palisade tissue, a smaller distribution of palisade layer thickness, increased OCT image contrast, and decreased OCT image homogeneity.
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Paper Nr: 39
Title:

Design and Simulation of Single-Mode and Polarization Independent Deeply Etched Amorphous Silicon on SOI Waveguides
Authors:

Babak Hashemi, Sandro Rao, Maurizio Casalino and Francesco D. Corte
Abstract: The conditions for simulating both single-mode behavior and polarization independence in deeply etched amorphous silicon (a-Si) on Silicon-On-Insulator (SOI) rib waveguides are presented and discussed. The paper aims to provide valuable insights and guidance for the design and optimization of waveguide-integrated electro-optic devices based on deeply etched hydrogenated amorphous silicon (a-Si:H)/SOI waveguides operating in a broad spectrum of wavelengths. The top layer of the waveguide consists of a-Si:H, whose deposition can be performed at low temperatures with no impact at all for previously fabricated CMOS-based electro-photonic integrated circuit.
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Paper Nr: 25
Title:

Numerical Evaluation of the Image Space Reconstruction Algorithm
Authors:

Tomohiro Aoyagi and Kouichi Ohtsubo
Abstract: In medical imaging modality, such as X-ray computerized tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT), image reconstruction from projection is to produce an image of a two-dimensional object from estimates of its line integrals along a finite number of lines of known locations. The method of tomographic image reconstruction from projection can be formulated with the Fredholm integral equation of the first kind, mathematically. It is necessary to solve the equation. But it is difficult in general to seek the strict solution. By discretizing the image reconstruction problem, we applied the image space reconstruction algorithm (ISRA) to the problem and evaluated the image quality. We computed the normalized mean square error (NMSE) in reconstructed image. We have shown that the error decreases with increasing the number of detectors, views and iterations. In addition, the effect of the relaxation parameter, the weighting factor and the noise to the reconstructed image are analysed.
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Area 3 - Photonics

Full Papers
Paper Nr: 17
Title:

Subwavelength Plasma Gratings Formation in the Process of Laser Modification in the Volume of Fused Silica
Authors:

Anna V. Bogatskaya, Ekaterina A. Volkova and Alexander M. Popov
Abstract: In this work, a numerical study of the formation of plasma periodic subwavelength nanogratings in fused silica along the propagation of a focused laser pulse is carried out. It is shown that the tightly focused beam creates a supercritical plasma in the focal plane, which provides an effective reflection of the parts of incident and reflected laser pulse. As a result, standing wave of ionization occurs which generates a plasma lattice with a period equal to the period of the standing wave in the medium. The results of modelling allow us to determine the optimal laser parameters in the regime of linear (geometrical) focusing when the contrast nanogratings can emerge. Analysis of energy release processes with subsequent melting of the fused silica sample confirms the previously proposed mechanism of laser modification.
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Short Papers
Paper Nr: 31
Title:

Accurate 3D Keypoints Annotation Method Based on LiDAR and Multi-Cameras System
Authors:

Yezhao Ju, Haiyang Zhang, Changming Zhao, Siyuan Fu and Ziyi Xu
Abstract: Deep learning-based 3D human key point recognition methods have developed rapidly in recent years, but 3D data annotation methods still have many unresolved problems in data annotations. In this paper, a data acquisition system based on multiple visible cameras and LIDAR systems is proposed for obtaining human body motion images and point cloud information. This method solves the problem that the traditional annotation method can only annotate specific points in the original LiDAR point cloud, and the annotated data is floating on the surface of the human body model instead of the centre of the human body joints, which leads to the problem of deviation of feature information extracted by the neural network. In addition, in terms of automated data annotation, the mature 2D human body key point recognition network can also be used to automatically annotate the 3D human body key point data.