Optical Systems Design最新文献

{"title":"Fabrication effects in the optical performance of DOEs engraved with femtosecond lasers","authors":"Angela Soria-Garcia, Jorge S. Fantova, Alejandro San Blas, J. del Hoyo, L. Sanchez-Brea, J. Alda, Ainara Rodríguez, S. Olaizola","doi":"10.1117/12.2597159","DOIUrl":"https://doi.org/10.1117/12.2597159","url":null,"abstract":"Diffractive Optical Elements (DOEs) are amplitude and/or phase masks that can be applied to light beams to modify their phase and/or intensity distribution. They are applied in holography, beam shaping, generation of exotic beams (Hermite-Gauss, Laguerre-Gauss, Gauss-Bessel, accelerating or vortex beams, etc.), generation of custom intensity profiles (top-hat, lines, figures, etc.), atomic physics, quantum optics, etc. They can be implemented using Spatial Light Modulators (SLMs) or micro-structured materials. Femtosecond laser writing is a very promising technique for fabricating photonic and micro-optics devices in metallic and dielectric materials. It consists on the removal (ablation) or modification of the irradiated material. Due to the short pulse duration of fs pulses, the energy is deposited in a localized region by nonlinear absorption mechanisms, allowing a very precise control of the material removal/modification. Compared to other methods, it has many advantages like a reduction of the amount of energy required to fabricate devices, and the absence of pollutant chemicals, becoming one of the most environmentally friendly fabrication techniques. One technique for implementing amplitude modulation DOEs is using dielectric samples covered with a metal thin film (few hundreds of nm thick). Then, the metallic film is selectively removed by laser ablation. This allows the engraving of a binary amplitude mask, where the remaining metallic coating reflects the electric field while the exposed dielectric area supports its transmission. Hence, these masks may work in both transmission and reflection. Although laser processing of DOEs has been successfully proved, some challenges still remain and should be addressed to optimize their behaviour. Several problems may arise during the laser ablation process. One of the problems treated in this contribution is the effect of damage on the dielectric substrate under the metallic coating. This happens since the light used to remove the metallic layer can also affect the dielectric sample, producing damage, variations of the material lattice or compositional changes, thus altering its refractive index. This variation may affect the effect of the DOE when it is used in transmission configuration. Another issue related to the ablation process is the different ablation strategies to engrave a given spatial distribution. Here, the laser is driven to process a matrix of points, or it can work in raster mode across the sample. We will analyze these two effects to properly understand the limitations of the technique and to find some useful strategies to overcome them when engraving DOEs through laser ablation.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126755855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical quality evaluation for active afocal systems","authors":"Xoana Barcala, E. Gambra, L. Sawides, Ivan Martinez-Ibarburu, V. Rodriguez-Lopez, C. Dorronsoro","doi":"10.1117/12.2596921","DOIUrl":"https://doi.org/10.1117/12.2596921","url":null,"abstract":"SimVis Gekko is a novel see-through binocular visual simulator that is based on liquid-membrane tunable lenses (TLs) projected onto the pupil of the eye using a twisted miniaturized 4-f system. Following a temporal multiplexing approach that introduces periodic defocus variations in optical power at 50Hz, the TL generates multifocal images on the retina of the observer, that look static. In this study, the image quality of different tentative designs of SimVis Gekko was evaluated for different optical powers. The full optical system of SimVis Gekko was computer simulated to get the spot size, prismatic shift, angular magnification, and field curvature up to 20° of field of view. An image quality bench was developed to capture and process images through the SimVis Gekko simulator. The system comprises a grayscale camera and a 19- mm focal-length lens with an adjustable diaphragm. A high-resolution screen was placed at one meter with two different targets: (1) a checkerboard, imaged through a 1-mm diaphragm, to measure optical quality, prismatic shift, magnification, and optical distortion; (2) a binary noise, imaged through a 5-mm diaphragm, used to measure the local field curvature and image quality. Images were obtained from 1 to 3D of the TL and automatically analyzed. Theoretical simulations and experimental measurements showed good agreement. Magnification and curvature were the major differences across designs. The last version measured was free of optical distortions with a central curvature-free area with high optical quality. The developed system could guide the assembly and fine adjustment of active afocal optical systems.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129023666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of the first lattice light-sheet microscope with incoherent holography (IHLLS) detection","authors":"M. Potcoava, C. Mann, J. Art, S. Alford","doi":"10.1117/12.2597117","DOIUrl":"https://doi.org/10.1117/12.2597117","url":null,"abstract":"The design of the first lattice light-sheet microscope equipped with incoherent holographic detection for neuronal imaging is presented. The device is designed for the capture of 3-D complex amplitude images moving neither the sample stage nor the detection microscope objective. The system is built onto a conventional lattice light-sheet (LLS) microscope, as a second detection arm, equipped with an incoherent holographic optical design and a monochromatic CMOS sensor. The compact system could be mounted on any lattice light-sheet and light sheet instruments due to flexibility of changing the numerical aperture of the excitation light by changing the anulus of the diffraction mask. For this study, fluorescence imaging is supported by illumination at 488 nm. This work relies upon the use of the self-interference property of the emitted fluorescent light, in which three or four Fresnel patterns are projected onto samples to create interference patterns of a 3-D object using a phase shifting technique. The projection of the diffraction patterns of samples is achieved with a spatial light modulator which allows single (IHLLS 1L) or dual lens (IHLLS 2L) patterns superposition with randomly selected pixels. The focal lengths of the lenses are calculated in two steps using OpticStudio (Zemax, LLC) design to provide the optimal compromise between the two requirements for magnification and dual-beam size matching at the camera plan on the one hand and space between the objective and camera on the other. We used the IHLLS-1L for calibration purposes and IHLLS-2L for recording sample holograms. The system allows the generation of high-resolution amplitude and phase images with larger scanning area and depth of field than the original LLS. Neuronal 3-D maps are built from sets of images acquired at various z-sections, determined by galvanometric mirror depth positions in the sample. This paper describes the concept of the instrument and details its optical design. This paper briefly describes the concept of the instrument and details its optical design. An overview of the key performances is also provided.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133903886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal strain between ultrashort laser pulse and tumor using finite element analysis","authors":"Jiahao Zeng, Ao Teng, Xianlin Song","doi":"10.1117/12.2596686","DOIUrl":"https://doi.org/10.1117/12.2596686","url":null,"abstract":"Photoacoustic imaging technology is an emerging functional imaging method in the field of biomedical applications. It combines the light absorption characteristics of tissues with the advantages of ultrasonic detection, and has the advantages of strong contrast, high sensitivity, and deep imaging depth. Therefore, this article uses the finite element software COMSOL Multiphysics to study the thermal expansion process of the photoacoustic effect caused by the interaction of ultrashort laser pulses with tissues. In COMSOL, a laser with a pulse width of 5 ns and a wavelength of 532 nm is used as the excitation light source. Use mathematics module, heat transmission module, solid mechanics module and pressure acoustics module to simulate the process of photothermal conversion-thermal expansion-generation of ultrasound in the photoacoustic imaging of the Gastric tissue-tumor system. In this way, the photoacoustic signal and its image are obtained. This research focuses on exploring the thermal expansion process in the photoacoustic effect.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121210864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly resistant all-silica polarizers for normal incidence applications","authors":"L. Grineviciute, Lukas Ramalis, R. Buzelis, T. Tolenis","doi":"10.1117/12.2597136","DOIUrl":"https://doi.org/10.1117/12.2597136","url":null,"abstract":"In this work we present a new all-silica coating - polarizer, which is also capable to withstand high density of radiation. In order to demonstrate the versatility of presented approach, several coating designs have been modelled and two of them fabricated together with the full-scale measurements and analysis necessary for polarizers implementation into high power microlaser systems. Two polarizing coatings at the wavelength of 355 nm have been formed using two stepper motors based GLAD system. Afterwards optical and structural analysis have been performed including spectrophotometric, atomic-force microscopy (AFM), scanning electron microscopy (SEM) and optical resistivity measurements.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116628883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectrograph with a composite holographic dispersive element","authors":"E. Muslimov, N. Pavlycheva, I. Guskov, D. Akhmetov, D. Kharitonov","doi":"10.1117/12.2596922","DOIUrl":"https://doi.org/10.1117/12.2596922","url":null,"abstract":"Aberration-corrected holographic gratings are widely used in spectral instruments. They allow to achieve high resolution and uniformly distributed diffraction efficiency as well as to combine several functions in a single optical element. However, their performance is limited. In particular, when the optical system has a large aperture the hologram replay conditions vary significantly across its’ surface. Due to this variation the hologram aberration properties and its efficiency change locally thus leading to decrease of the resolution and efficiency of the entire system. In the present research we consider a composite volume phase holographic optical element used as a disperser in a spectrograph design. Such an optical element represent a hologram recorded by stitching of several elementary fields or zones. The refraction index modulation depth, the fringes tilt and the hologram spatial frequency may vary locally in each of the elementary fields to match the changing reconstruction conditions. This approach allows to implement a better aberrations correction and to maximize the overall diffraction efficiency. We demonstrate an exemplary spectrograph design with a composite hologram for the visible range of 400-800 nm. It is shown, that in the design as fast as f/2.1 the maximum aberrations can be decreased by factor of 1.19 and 2 in the X and Y directions, respectively, while the average diffraction efficiency increases by 15.6% at shorter wavelenghts. We continue the study by investigation of the composite hologram technological feasibility and demonstrate that it can be recorded with a standard precision of the moving sources positioning, achievable stroke of the auxiliary deformable mirror and reasonably high accuracy of the photosensitive layer’s parameters.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"11871 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130354635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical design applied to an effective inactivation of airborne pathogens","authors":"M. Lombini, E. Diolaiti, A. De Rosa, L. Lessio, G. Pareschi, A. Bianco, F. Cortecchia, M. Fiorini, G. Fiorini, G. Malaguti, A. Zanutta","doi":"10.1117/12.2597087","DOIUrl":"https://doi.org/10.1117/12.2597087","url":null,"abstract":"The inactivation or airborne pathogens inside closed spaces is a critical issue that raised overwhelmingly during the current SARS-CoV 2 pandemic. Among the different technologies to achieve air sanification, the ultraviolet germicidal irradiation is a trending technique, also due to the fast development of more and more effective ultra-violet LED sources, that are expected to replace the mercury vapor lamps in the next few years. The positioning of LEDs inside cavities with highly reflective surfaces permits an enhancement of the internal irradiance and the development of compact devices. Optical simulations, by means of ray tracing, are fundamental, since an accurate irradiance estimation in presence of multiple internal reflections, scattering, light leaks outside the cav-ity and the sources angular emission distribution is not possible with only analytical calculations. Ray tracing permits to model the spatial irradiance inside the cavity by varying the components parameters to maximize the inactivation rate as a function of the air flow field. We discuss, on the basis of the experience on several related projects, the advantages of using the numerical approach to simulate these devices, focusing the attention onto the critical parameters which must be controlled to retrieve a reliable estimation of the system performance.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130356864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescent light guides based on Dy-doped borate glass","authors":"M. Grüne, A. C. Rimbach, S. Schweizer","doi":"10.1117/12.2596790","DOIUrl":"https://doi.org/10.1117/12.2596790","url":null,"abstract":"Lithium aluminoborate glass optically activated with the lanthanide ion dysprosium is investigated for its potential as luminescent light guide. For this, ray-tracing simulations are performed on the basis of transmission, photoluminescence, and quantum efficiency measurements. The luminous flux at the end of the light guide depends significantly on its length as well as on the roughness of the output face. The best results are obtained for a light guide length of approximately 70-80 mm with the side faces of the light guide coated with a 100 % reflecting mirror and a rough output face with Lambertian scattering characteristic. The input face is coated with a half-transmitting mirror which is transmissive for the excitation wavelength of 388 nm but reflective for the emission bands in the visible spectral range. For this light guide, a luminance of approximately 20 cd/mm2 is achieved for an excitation power density of 1W/mm2. The geometry of the light guide (cuboid / cylinder) has only a slight effect on the maximum luminance value.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128222615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling real life LED spectra from data sheet information only","authors":"J. Muschaweck","doi":"10.1117/12.2601775","DOIUrl":"https://doi.org/10.1117/12.2601775","url":null,"abstract":"LEDs not only have widely varying spectral (and electrical) properties at the fixed temperature and current \"grouping conditions\" used to characterize them after production, to group them into \"bins\". LED spectrum and voltage also change with temperature and current in operation. For an actual product, it is nontrivial to predict spectra and voltages from limited information in data sheets for real life driving conditions. We show how spectra and voltages can indeed be predicted from data sheet values, and which generic a priori information about LEDs is required in addition, demonstrating our open source, public domain Matlab implementation.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128838517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the frame rate limit for the estimation of the vibration measurements in a mechanical system using optical techniques","authors":"V. Moreno-Oliva, Jose Angel Desales-Dominguez, Edwin Román-Hernández, M. Campos-García","doi":"10.1117/12.2592800","DOIUrl":"https://doi.org/10.1117/12.2592800","url":null,"abstract":"In this work, we analyze the advantages and limitations of the systems of low speeds of frames per second (fps) for the estimation of the vibrations measurements in systems where optical techniques are used. The acquisition systems with low fps are interesting because they are not expensive. In this way, the aim of this work is to compute the limit speed to obtain good resolutions in data collection. Laser triangulation technique is implemented to determine the natural frequency of vibration of a system using a cantilever beam, as a standard example. The results are compared, with a commercial accelerometer.","PeriodicalId":217586,"journal":{"name":"Optical Systems Design","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125062000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}