International School on Quantum Electronics: Laser Physics and Applications最新文献

{"title":"Optical polymers for laser medical applications","authors":"N. Sultanova, S. Kasarova, I. Nikolov","doi":"10.1117/12.2249843","DOIUrl":"https://doi.org/10.1117/12.2249843","url":null,"abstract":"In medicine, optical polymers are used not only in ophthalmology but in many laser surgical, diagnostic and therapeutic systems. The application in lens design is determined by their refractive and dispersive properties in the considered spectral region. We have used different measuring techniques to obtain precise refractometric data in the visible and near-infrared spectral regions. Dispersive, thermal and other important optical characteristics of polymers have been studied. Design of a plastic achromatic objective, used in a surgical stereo-microscope at 1064 nm laser wavelength, is accomplished. Geometrical and wavefront aberrations are calculated. Another example of application of polymers is the designed all-mirror apochromatic micro-lens, intended for superluminescent diode fiber coupling in medical systems.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133659183","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":"Slow and fast light in five-level system","authors":"G. Grigoryan, E. Gazazyan, V. Paturyan","doi":"10.1117/12.2260437","DOIUrl":"https://doi.org/10.1117/12.2260437","url":null,"abstract":"We have studied the propagation of light in M- and W-systems, and have demonstrated the possibility of such propagation with nonlinear group velocity being either less than (slow light) or greater than (superluminal propagation) of the speed of light in vacuum without being distorted.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"56 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114002094","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":"Dispersion control in a folded 4-f system for shaping femtosecond laser pulses","authors":"N. Dimitrov, P. Lazarova, L. Stoyanov, I. Stefanov, A. Dreischuh","doi":"10.1117/12.2264705","DOIUrl":"https://doi.org/10.1117/12.2264705","url":null,"abstract":"In this work we study the influence of the additional second-order dispersion introduced in sub-45 femtosecond laser pulses by intentional misaligning a folded 4-f otherwise dispersionless system. The theoretically calculated pulse durations are found to be in a good agreement with the respective experimental data from frequency-resolved optical gating measurements.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123005799","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":"Nonlinear optical microscopy for investigation of gastrointestinal lesions","authors":"T. Genova, Ekaterina Borisova, G. Stanciu, D. Tranca, I. Terziev, N. Penkov, B. Vladimirov, M. Lomova, O. Semyachkina-Glushkovskaya, L. Avramov","doi":"10.1117/12.2260712","DOIUrl":"https://doi.org/10.1117/12.2260712","url":null,"abstract":"The standard procedure for cancer detection includes rigorous biopsy protocols, which are costly and time consuming; also the accuracy of the current diagnostic procedure relays entirely on the physician’s experience and it is limited by the high probability of miss rates. Therefore new sensitive diagnostic modalities for analysis of biopsy tissue samples or on site, in vivo microscopy tissue examination, are necessary. In this study we present an investigation using nonlinear microscopy techniques for histological sections from biopsy tissue samples analysis. The samples were routinely processed for histological analysis and during the standard sampling the tissue slices were stained with hematoxylin and eosin dyes. The application of nonlinear microscopy techniques, such as two photon excitation fluorescence microscopy and second harmonic generation microscopy in biomedical research for cancer diagnosis has been vastly expanding in the last few years. Two-photon excitation fluorescence microscopy is based on a non-linear optical effect of simultaneously absorption of two photons, thus achieves excited state of the absorbing molecule with energy corresponding to the sum of the energies of two incident photons. This method allows for using an excitation wavelength which is double the typically required one for excitation of diagnostically valuable endogenous fluorophores. This results in more efficient depth penetration of the longer wavelength light in the tissue. The second harmonic generation microscopy is based on the principle of the non-linear susceptibility in noncentrosymmetric structures; such structures in the tissue are formed mainly by the collagen fibers. After excitation with near-infrared photons with wavelength λ of the collagen structures, photons with wavelength ½ λ are emitted — this corresponding to the second harmonic of the excitation beam’s frequency. The applied nonlinear microscopy techniques are suitable for detection and quantification of the morphological changes associated with stroma and epithelial transformation in colon cancer, providing complementary information about the tissue microstructure and displaying distinctive patterns between normal and malignant human colon tissues.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126710892","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":"Detection of plum pox virus infection in selection plum trees using spectral imaging","authors":"L. Angelova, A. Stoev, E. Borisova, L. Avramov","doi":"10.1117/12.2261807","DOIUrl":"https://doi.org/10.1117/12.2261807","url":null,"abstract":"Plum pox virus (PPV) is among the most studied viral diseases in the world in plants. It is considered to be one of the most devastating diseases of stone fruits in terms of agronomic impact and economic importance. Noninvasive, fast and reliable techniques are required for evaluation of the pathology in selection trees with economic impact. Such advanced tools for PPV detection could be optical techniques as light-induced fluorescence and diffuse reflectance spectroscopies. Specific regions in the electromagnetic spectra have been found to provide information about the physiological stress in plants, and consequently, diseased plants usually exhibit different spectral signature than non-stressed healthy plants in those specific ranges. In this study spectral reflectance and chlorophyll fluorescence were used for the identification of biotic stress caused by the pox virus on plum trees. The spectral responses of healthy and infected leaves from cultivars, which are widespread in Bulgaria were investigated. The two applied techniques revealed statistically significant differences between the spectral data of healthy plum leaves and those infected by PPV in the visible and near-infrared spectral ranges. Their application for biotic stress detection helps in monitoring diseases in plants using the different plant spectral properties in these spectral ranges. The strong relationship between the results indicates the applicability of diffuse reflectance and fluorescence techniques for conducting health condition assessments of vegetation and their importance for plant protection practices.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125726146","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":"Laser annealing of metal nanoparticles synthesized in glasses by ion implantation","authors":"A. Stepanov","doi":"10.1117/12.2261914","DOIUrl":"https://doi.org/10.1117/12.2261914","url":null,"abstract":"Recent results on the interaction of high power laser pulses with dielectrics containing metal nanoparticles are observed. The excimer laser pulse modification of copper nanoparticles synthesized by ion implantation in silicate glass are considered. Pulsed laser irradiation makes it possible to modify such composite layer, improving the uniformity in the size distribution of the nanoparticles. Changes induced by pulsed laser exposure suggest there are both reductions in average size of the metal nanoparticles, and some long-range dissolution of metal atoms in the matrix. Experimental data on laser modification are explained by photofragmentation of the nanoparticles in the dielectric matrix.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"232 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114204493","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":"Three-dimensional imaging of cultural heritage artifacts with holographic printers","authors":"Hoonjong Kang, E. Stoykova, N. Berberova, Jiyong Park, D. Nazarova, J. Park, Youngmin Kim, Sunghee Hong, B. Ivanov, N. Malinowski","doi":"10.1117/12.2262068","DOIUrl":"https://doi.org/10.1117/12.2262068","url":null,"abstract":"Holography is defined as a two-steps process of capture and reconstruction of the light wavefront scattered from three-dimensional (3D) objects. Capture of the wavefront is possible due to encoding of both amplitude and phase in the hologram as a result of interference of the light beam coming from the object and mutually coherent reference beam. Three-dimensional imaging provided by holography motivates development of digital holographic imaging methods based on computer generation of holograms as a holographic display or a holographic printer. The holographic printing technique relies on combining digital 3D object representation and encoding of the holographic data with recording of analog white light viewable reflection holograms. The paper considers 3D contents generation for a holographic stereogram printer and a wavefront printer as a means of analogue recording of specific artifacts which are complicated objects with regards to conventional analog holography restrictions.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"389 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123515270","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":"Determination of gas-discharge plasma parameters in powerful metal halide vapor lasers","authors":"K. Temelkov, S. I. Slaveeva, Yu I Fedchenko","doi":"10.1117/12.2261668","DOIUrl":"https://doi.org/10.1117/12.2261668","url":null,"abstract":"Powerful metal halide vapor lasers are excited with nanosecond pulsed longitudinal discharge in complex multicomponent gas mixtures. Using a new method, thermal conductivity of various 5- and 6-component gas mixtures is obtained under gas-discharge conditions, which are optimal for laser operation on the corresponding metal atom and ion transitions. Assuming that the gas temperature varies only in the radial direction and using the calculated thermal conductivities, an analytical solution of the steady-state heat conduction equation is found for uniform and radially nonuniform power input in various laser tube constructions. Using the results obtained for time-resolved electron temperature by measurement of electrical discharge characteristics and analytically solving steady-state heat conduction equation for electrons as well, radial distribution of electron temperature is also obtained for the discharge period.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129255714","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":"Slow terahertz light via resonant tunneling induced transparency in quantum well heterostructures","authors":"P. Tzenov, C. Jirauschek","doi":"10.1117/12.2262367","DOIUrl":"https://doi.org/10.1117/12.2262367","url":null,"abstract":"We present a theoretical and computational investigation of the possibility of achieving slow terahertz light by exploiting the tunneling induced transparency (TIT) effect in suitably engineered quantum well heterostructure devices. We design such a meta-material and show how TIT could lead to large values of the group refractive index, unfortunately at the cost of strong field attenuation due to decoherence. As a suitable alternative, we propose a grating, consisting of a buffer and a quantum cascade amplifier regions, arranged in such a way as to achieve slow light and simultaneously compensate for the large signal losses. Our calculations show that a binary message could be reliably transmitted through this system, with non-critical reduction of the signal to noise ratio, as we achieve a slow-down factor of more than 70.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124058287","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":"Optimal contrast elastic lidar sensing of clear and aerosol-loaded atmosphere","authors":"T. Evgenieva, L. Gurdev","doi":"10.1117/12.2261413","DOIUrl":"https://doi.org/10.1117/12.2261413","url":null,"abstract":"The sensing laser radiation wavelength is one of the most significant factors conditioning the elastic lidar efficiency. Nevertheless, its role in the process of lidar sensing has not been investigated systematically so far. Therefore, the main purpose of the present work is to develop and perform an initial examination of an approach to solve this problem based on modeling the profile of the lidar return signal (the lidar profile) and evaluating, in a specific way, the corresponding profile of the measurement signal-to-noise ratio (SNR). The measurement fluctuations are considered as mainly due to the Poisson shot noise that is intrinsic to the dark current and the photocurrent induced by the useful signal itself and the atmospheric background. The initial results obtained show for instance that for ground-based lidar facilities the maximum Rayleigh return signal is obtainable at wavelengths about 350nm. The roles are changed when sensing clouds using wavelength from 400nm to 1000-2000nm. Then, the longer wavelengths provide higher return power from clouds, and the effect is magnified in aerosol-loaded (and especially hazy) atmosphere. The results of such investigations are useful when selecting optimal lidar-design characteristics ensuring maximum brightness and contrast of the lidar-acquired images of specific aerosol strata and objects in the atmosphere.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115072789","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}