725 research outputs found

    Advanced photonic and electronic systems WILGA 2018

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    WILGA annual symposium on advanced photonic and electronic systems has been organized by young scientist for young scientists since two decades. It traditionally gathers around 400 young researchers and their tutors. Ph.D students and graduates present their recent achievements during well attended oral sessions. Wilga is a very good digest of Ph.D. works carried out at technical universities in electronics and photonics, as well as information sciences throughout Poland and some neighboring countries. Publishing patronage over Wilga keep Elektronika technical journal by SEP, IJET and Proceedings of SPIE. The latter world editorial series publishes annually more than 200 papers from Wilga. Wilga 2018 was the XLII edition of this meeting. The following topical tracks were distinguished: photonics, electronics, information technologies and system research. The article is a digest of some chosen works presented during Wilga 2018 symposium. WILGA 2017 works were published in Proc. SPIE vol.10445. WILGA 2018 works were published in Proc. SPIE vol.10808

    Study of resonant reflection in helicoidal photonic band gap structures

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    La présente thèse de doctorat rapporte une étude expérimentale sur la réflexion résonante de la lumière dans des structures hélicoïdales à bande photonique interdite. Plusieurs aspects optiques et électro-optiques des cristaux liquides cholestériques sont abordés en concentrant l’attention sur deux effets principaux: l’influence des conditions aux limites (mécaniques et optiques) sur les propriétés optiques des couches de cristaux liquides cholestériques et le contrôle de la bande interdite de ces dernières. On présente un élément à double-rétroaction optique basé sur une cavité de Fabry-Pérot remplie de cristal liquide cholestérique. Les propriétés spectrales et de polarisation de cet élément sont caractérisées expérimentalement et par des simulations théoriques. Un changement mineur dans la structure en haut (cavité de Fabry-Pérot) nous a permis d’obtenir une transmission non-réciproque de la lumière sans application d’un champ externe à l’élément en question. Nous avons observé une transmission non-réciproque de la lumière par un système qui ressemble beaucoup aux structures naturelles observées sur certaines carapaces d’insectes (par exemple, sur les élytres de certains coléoptères): une simple couche de matière transparente linéaire dans son état fondamental. L’effet est défini par deux facteurs principaux: la chiralité et la périodicité de la matière ainsi que les conditions asymétriques aux surfaces limites. Concernant la partie sur le contrôle de la bande interdite, nous présentons la création et l’utilisation du mélange de cristal liquide cholestérique à deux fréquences pour le ‘déroulement’ et la reconstruction dynamique de la structure hélicoïdale. Le processus de reconstruction est accéléré d’un ordre de grandeur par l’application de champs électriques modérés. L’étape suivante du contrôle de la bande interdite est l’accord en longueur d’onde de la bande interdite. Un effet électromécanique est utilisé pour générer et étudier l’auto-adaptation du pas d’hélice de la couche de cristal liquide cholestérique. L’anisotropie négative diélectrique a permis d’assurer la stabilisation de la structure hélicoïdale de la couche pendant l’application du champ électrique qui a aussi changé l’épaisseur de la couche de cristal liquide en pliant un des substrats minces de la cellule. Cette déformation de la couche a généré un d’accord (et des sauts) des longueurs d’onde de la bande interdite. Les études spectrales et morphologiques pendant les changements de la bande interdite sont présentées et discutées.The present PhD thesis reports experimental study of resonant reflection in helicodal photonic band gap structures. Several optical and electro-optical properties of cholesteric liquid crystals are investigated where attention was concentrated on two principal phenomena: the influence of mechanical and optical boundary conditions on optical properties of cholesteric liquid crystal layers and control of photonic band gap of cholesteric liquid crystals. The creation of a double-feedback optical element based on a Fabry-Perot cavity filled with a planar aligned cholesteric liquid crystal mixture is presented. The polarization and spectral properties of this element are characterized experimentally and simulated theoretically. Experimental results are obtained for the transmittance dependence upon the orientation of the linear polarization plane and the polarization state of incident probe beam. A slight change in above mentioned structure (Fabry-Perot cavity) let us obtain a non-reciprocal transmittance of light without applying any external field. We observed an optical non reciprocity in a material system that is very close to natural structures, such as insect skin: a single layer of linear transparent material in its ground state. The process is shown to be defined by two key parameters: the chiral and periodic nature of the material and its asymmetric boundary conditions. In the part of band gap control, we present the creation and the use of dual frequency cholesteric liquid crystal mixtures for the dynamic electrical unwinding and forced (accelerated) restoring of their molecular helix. The restoring process is accelerated almost by an order of magnitude for quite moderate voltages used. The next step of band gap control is the tuning of band gap (wavelength). Strong electromechanical effect was used to generate and study self-adaptation and pitch jumps in a layer of cholesteric liquid crystal. The negative dielectric anisotropy of the material allowed its stabilization by the electric field and important thickness changes, achieved thanks to the use of a very thin substrate, allowed the observation of multiple dynamic jumps at fixed deformation conditions. Spectral and morphological studies of the material during those jumps were performed and are presented

    Art and Technology: coherence, connectedness, and the integrative field

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    Merged with duplicate record 10026.1/690 on 03.04.2017 by CS (TIS)This thesis is a theoretical and practical intervention in the field of art and technology. It proceeds from the re-examination of four specific domains that in the past 40 years have considerably informed the invention of new aesthetic forms. They are: art, science, nature and technology. We have identified that each one of these domains and the way they inform one another reflects the influence of a Western analytical tradition based on fragmentation, dichotomies and dualities. In consequence of this, art of the last decades has suffered from a sort of mechanistic thought which results from a predominantly weary aesthetic model, founded in dualities such as: object/process, form/behaviour, meaning/information. The main question that the present study addresses is how to overcome this predominantly reductionist inheritance and to develop an aesthetic model able to interconnect in an integrative fashion those disparate domains, respective discourses and practices? The answer to this question, developed throughout this thesis, is an aesthetic principle built upon the notions of resonance, coherence and field models, rooted in an integrative view of living organisms based on the theory of biophotons. This constitutes the main contribution of the thesis to new knowledge. The theoretical approach of this thesis is developed upon the revision of the concept of form, supported by a Gestalt analysis as provided by Rudolf Arnheim, and has involved the consideration of the ideas of Gilbert Simondon (the concept of "concretisation") and Vilem Flusser (the concept of "apparatus"), in order to gain a deeper insight into the nature of technology. In conclusion, the practice-based methodology of this thesis has been to develop artworks based on the confluence of living organisms (plants) and artificial systems in order to permit empirical observation and reflection on the proposed theory. The major outcome of the practice is the artwork "Breathing", a hybrid creature made of a living organism (a plant) and an artificial system. The creature responds to its environment through movement, light and the noise of its mechanical parts and interacts with the observer through his/her act of breathing. This work is the result of an investigation into plants as sensitive agents for the creation of art. The intention was to explore new forms of artistic experience through the dialogue of natural and artificial processes

    Ancient and historical systems

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    Roadmap for optical tweezers

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    Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMOptical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects, ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in the life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nano-particle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space explorationEuropean Commission (Horizon 2020, Project No. 812780

    Roadmap for optical tweezers

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    Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects, ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in the life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nano-particle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration.journal articl

    Roadmap for Optical Tweezers 2023

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    Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nanoparticle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration

    Tinkering with the Unbearable Lightness of Being: Meditation, Mind-Body Medicine and Placebo in the Quantum Biology Age

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    There are empirical indications that mind-body therapies have a nonlocal quantum component, in addition to the psychoneuroimmunological pathways that have been the focus of the predominant experimental paradigm.  The discussion below addresses the evidence and proposed theoretical mechanisms supporting this conclusion, and makes the case that there should be a convergence of research agendas between mind-body interventions (including placebo),  photomedicine and quantum biology.  Specifically, the role of endogenously generated biophotons in the regulation of genetic expression and the apparent ability of mental intent to direct biophoton emissions to specifically targeted tissues needs to be further evaluated from the perspective of photobiomodulation mechanisms, with a special focus on the spectroscopy and dosimetry of these emissions. Finally, the possible role of long-term meditation in enhancing quantum biological effects has to be further investigated at the level of cellular and macromolecular remodeling, both in the brain and the body

    Advanced Photonic Sciences

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    The new emerging field of photonics has significantly attracted the interest of many societies, professionals and researchers around the world. The great importance of this field is due to its applicability and possible utilization in almost all scientific and industrial areas. This book presents some advanced research topics in photonics. It consists of 16 chapters organized into three sections: Integrated Photonics, Photonic Materials and Photonic Applications. It can be said that this book is a good contribution for paving the way for further innovations in photonic technology. The chapters have been written and reviewed by well-experienced researchers in their fields. In their contributions they demonstrated the most profound knowledge and expertise for interested individuals in this expanding field. The book will be a good reference for experienced professionals, academics and researchers as well as young researchers only starting their carrier in this field

    2013 Symposium Brochure

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