V. Skvortsova, Ņ. Mironova-Ulmane, L. Trinkler, L. Grigorjeva
The photoluminescence (PL), its excitation (PLE) and absorption spectra in ultraviolet, visible and infrared (UV-VIS-IR) regions were used to investigate the MgO single crystals irradiated by fast neutrons. It is shown that the photoluminescence band of the MgO crystals at 730 nm belongs to the hydrogen-containing complex centers V-OH-Fe3+, which are transformed during the irradiation with fast neutrons. The behavior of the PL band 730 nm after fast neutron irradiation depends on the iron-chromium concentration. It is found that the fast neutron irradiation produces the interstitial proton H+i and the Mg(OH)2 microphase.
{"title":"Optical properties of hydrogen-containing MgO crystal","authors":"V. Skvortsova, Ņ. Mironova-Ulmane, L. Trinkler, L. Grigorjeva","doi":"10.1117/12.815778","DOIUrl":"https://doi.org/10.1117/12.815778","url":null,"abstract":"The photoluminescence (PL), its excitation (PLE) and absorption spectra in ultraviolet, visible and infrared (UV-VIS-IR) regions were used to investigate the MgO single crystals irradiated by fast neutrons. It is shown that the photoluminescence band of the MgO crystals at 730 nm belongs to the hydrogen-containing complex centers V-OH-Fe3+, which are transformed during the irradiation with fast neutrons. The behavior of the PL band 730 nm after fast neutron irradiation depends on the iron-chromium concentration. It is found that the fast neutron irradiation produces the interstitial proton H+i and the Mg(OH)2 microphase.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127966213","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}
K. Lieb, S. Gasiorek, J. Keinonen, P. Sahoo, T. Sajavaara
Even small fluences of implanted ions used for opto-doping alpha-quartz lead to amorphization of the matrix, but subsequent annealing in air or oxygen can restore its crystalline order (chemical epitaxy). Here we report on cathodoluminescence (CL) spectroscopy during chemical epitaxy of alpha-quartz irradiated with 50-keV Na-ions or 175-keV Rb ions and annealed in 18O2-gas. In particular, the variation of the CL spectra with the ion fluence will be discussed. The CL spectra at 10 K show an intense 2.90-2.95 eV blue band and differ greatly from the ones taken at 300 K. Finally we report on the observation of a spider-web surface structure after Rb implantation and annealing in lowpressure oxygen.
{"title":"Alkali-ion irradiated alpha-quartz: low-temperature cathodoluminescence after chemical epitaxy","authors":"K. Lieb, S. Gasiorek, J. Keinonen, P. Sahoo, T. Sajavaara","doi":"10.1117/12.814237","DOIUrl":"https://doi.org/10.1117/12.814237","url":null,"abstract":"Even small fluences of implanted ions used for opto-doping alpha-quartz lead to amorphization of the matrix, but subsequent annealing in air or oxygen can restore its crystalline order (chemical epitaxy). Here we report on cathodoluminescence (CL) spectroscopy during chemical epitaxy of alpha-quartz irradiated with 50-keV Na-ions or 175-keV Rb ions and annealed in 18O2-gas. In particular, the variation of the CL spectra with the ion fluence will be discussed. The CL spectra at 10 K show an intense 2.90-2.95 eV blue band and differ greatly from the ones taken at 300 K. Finally we report on the observation of a spider-web surface structure after Rb implantation and annealing in lowpressure oxygen.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133297006","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}
In this work we present an interpretation of experimental O K-edge x-ray absorption near edge structure (XANES) in perovskite-type WO3 and AWO3 compounds (A = H and Na) using three different first principles approaches: (i) fullmultiple- scattering (FMS) formalism (the real-space FEFF code), (ii) hybrid density functional theory (DFT) method with partial incorporation of exact Hartree-Fock exchange using formalism of the linear combination of atomic orbitals (LCAO) as implemented in the CRYSTAL code; (iii) plane-wave DFT method using formalism of the projectoraugmented waves (PAW) as implemented in the VASP code.
{"title":"Quantum chemistry studies of the O K-edge x-ray absorption in WO3 and AWO3","authors":"D. Bocharov, A. Kuzmin, J. Purāns, Y. Zhukovskii","doi":"10.1117/12.815297","DOIUrl":"https://doi.org/10.1117/12.815297","url":null,"abstract":"In this work we present an interpretation of experimental O K-edge x-ray absorption near edge structure (XANES) in perovskite-type WO3 and AWO3 compounds (A = H and Na) using three different first principles approaches: (i) fullmultiple- scattering (FMS) formalism (the real-space FEFF code), (ii) hybrid density functional theory (DFT) method with partial incorporation of exact Hartree-Fock exchange using formalism of the linear combination of atomic orbitals (LCAO) as implemented in the CRYSTAL code; (iii) plane-wave DFT method using formalism of the projectoraugmented waves (PAW) as implemented in the VASP code.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130952606","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}
The contribution of Yu.N.Denisyuk, E.Leuth, and Yu.Upatnieks into holographic science and technology is considered from the point of view of the modern state in holography. Some biographical data of these outstanding specialists are given, and their significance in the holography development is estimated.
{"title":"Yu. N. Denisyuk, E. Leith, and J. Upatnieks: founders of volume and laser holography","authors":"S. Gurevich","doi":"10.1117/12.815461","DOIUrl":"https://doi.org/10.1117/12.815461","url":null,"abstract":"The contribution of Yu.N.Denisyuk, E.Leuth, and Yu.Upatnieks into holographic science and technology is considered from the point of view of the modern state in holography. Some biographical data of these outstanding specialists are given, and their significance in the holography development is estimated.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132647941","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}
In pediatric ophthalmology 2 - 3 % of all the children are impacted by a visual pathology - amblyopia. It develops if a clear image isn't presented to the retina during an early stage of the development of the visual system. A common way of treating this pathology is to cover the better-seeing eye to force the "lazy" eye to learn seeing. However, children are often reluctant to wear such an occluder because they are ashamed or simply because they find it inconvenient. This fact requires to find a way how to track the regime of occlusion because results of occlusion is a hint that the actual regime of occlusion isn't that what the optometrist has recommended. We design an electronic eye occluder that allows to track the regime of eye occlusion. We employ real-time clock DS1302 providing time information from seconds to years. Data is stored in the internal memory of the CPU (EEPROM). The MCU (PIC16F676) switches on only if a mechanical switch is closed and temperature has reached a satisfactory level. The occlusion is registered between time moments when the infrared signal appeared and disappeared.
{"title":"Electronic eye occluder with time-counting and reflection control","authors":"V. Karitans, M. Ozolinsh, G. Kuprisha","doi":"10.1117/12.815953","DOIUrl":"https://doi.org/10.1117/12.815953","url":null,"abstract":"In pediatric ophthalmology 2 - 3 % of all the children are impacted by a visual pathology - amblyopia. It develops if a clear image isn't presented to the retina during an early stage of the development of the visual system. A common way of treating this pathology is to cover the better-seeing eye to force the \"lazy\" eye to learn seeing. However, children are often reluctant to wear such an occluder because they are ashamed or simply because they find it inconvenient. This fact requires to find a way how to track the regime of occlusion because results of occlusion is a hint that the actual regime of occlusion isn't that what the optometrist has recommended. We design an electronic eye occluder that allows to track the regime of eye occlusion. We employ real-time clock DS1302 providing time information from seconds to years. Data is stored in the internal memory of the CPU (EEPROM). The MCU (PIC16F676) switches on only if a mechanical switch is closed and temperature has reached a satisfactory level. The occlusion is registered between time moments when the infrared signal appeared and disappeared.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114917219","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}
In connection with 60th anniversary of new optical division - holography - the significant changes are considered which occurred due to holography in the area of recording and storage of information carrying by light. New recording media are discovered, and some old recording media are significantly improved, new recording methods of light information recording and storage are proposed. It is noted that despite the prominent achievements, a very wide work regarding holographic information recording and storage media and methods lies ahead in order to realize the possibilities of holography more completely.
{"title":"The problems of holographic information recording and storage: modern state","authors":"B. Gurevich, S. Gurevich, A. Peckus","doi":"10.1117/12.815427","DOIUrl":"https://doi.org/10.1117/12.815427","url":null,"abstract":"In connection with 60th anniversary of new optical division - holography - the significant changes are considered which occurred due to holography in the area of recording and storage of information carrying by light. New recording media are discovered, and some old recording media are significantly improved, new recording methods of light information recording and storage are proposed. It is noted that despite the prominent achievements, a very wide work regarding holographic information recording and storage media and methods lies ahead in order to realize the possibilities of holography more completely.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122210646","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}
M. Karaliūnas, E. Kuokštis, K. Kazlauskas, S. Juršėnas, Veit Hoffman, A. Knauer
Stimulated emission dynamics in InGaN-based multiple quantum wells (MQWs) is analyzed. The lasing threshold measurements of the In0.09Ga0.91N/In0.02Ga0.98N MQWs revealed non-monotonous threshold dependence on the growth temperature of the active MQW region. The optimal growth temperature range with the lowest stimulated emission threshold (100 kW/cm2) in the active region was found to be 780 - 800°C. The influence of indium nano-clusters on stimulated emission threshold is discussed. Optical gain in InGaN MQWs was measured using variable excitation stripe length technique. The optical gain dependence on excitation stripe length and excitation power density was studied. The onset of the gain saturation was observed on the high energy side of the stimulated emission peak. The onset exhibited red-shift with increasing stripe length due to reduced electron-hole density caused by high optical transition rate. Increase of excitation power density resulted in the strong blue-shift of the optical gain spectra. The maximal optical gain coefficient values of 200 cm-1 and 300 cm-1 were obtained for the samples with the lowest and the highest stimulated emission thresholds, respectively. The calculated optical confinement factor (3.4 %) for the samples yielded the net gain coefficient of about 5900 cm-1 and 8800 cm-1, respectively
{"title":"Optical gain dynamics in InGaN/InGaN quantum wells","authors":"M. Karaliūnas, E. Kuokštis, K. Kazlauskas, S. Juršėnas, Veit Hoffman, A. Knauer","doi":"10.1117/12.816514","DOIUrl":"https://doi.org/10.1117/12.816514","url":null,"abstract":"Stimulated emission dynamics in InGaN-based multiple quantum wells (MQWs) is analyzed. The lasing threshold measurements of the In0.09Ga0.91N/In0.02Ga0.98N MQWs revealed non-monotonous threshold dependence on the growth temperature of the active MQW region. The optimal growth temperature range with the lowest stimulated emission threshold (100 kW/cm2) in the active region was found to be 780 - 800°C. The influence of indium nano-clusters on stimulated emission threshold is discussed. Optical gain in InGaN MQWs was measured using variable excitation stripe length technique. The optical gain dependence on excitation stripe length and excitation power density was studied. The onset of the gain saturation was observed on the high energy side of the stimulated emission peak. The onset exhibited red-shift with increasing stripe length due to reduced electron-hole density caused by high optical transition rate. Increase of excitation power density resulted in the strong blue-shift of the optical gain spectra. The maximal optical gain coefficient values of 200 cm-1 and 300 cm-1 were obtained for the samples with the lowest and the highest stimulated emission thresholds, respectively. The calculated optical confinement factor (3.4 %) for the samples yielded the net gain coefficient of about 5900 cm-1 and 8800 cm-1, respectively","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"258 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120874582","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}
I. Mihailova, V. Gerbreders, Ē. Sļedevskis, V. Kolbjonoks, E. Tamanis
The article examines the processes of second harmonic generation (SHG) when selenium-metal (Cu) film structures are illuminated by femtosecond radiation (180 fs, 80 MHz) at wavelength 800 - 1000 nm. Selenium-copper structures were obtained by successive thermal evaporation of selenium and copper onto the glass substrate in vacuum. Microanalysis of the film composition was performed to determine amount of copper in thin films. The as-evaporated selenium-copper structures were crystallised by annealing in inert atmosphere at temperature 85°C. Just evaporated as well as annealed thin films were explored. The experiment was performed by confocal microscope [1] where the femtosecond radiation from laser was injected. A photosensitivity of structures in question was then determined as functions of intensity and wavelength of the incident radiation [2]. Second harmonic intensity dependence on thickness of Cu layer was also observed. We found out that adding small amount of Cu increases reflected SH intensity.
{"title":"Second harmonic generation in selenium-metal structures","authors":"I. Mihailova, V. Gerbreders, Ē. Sļedevskis, V. Kolbjonoks, E. Tamanis","doi":"10.1117/12.815609","DOIUrl":"https://doi.org/10.1117/12.815609","url":null,"abstract":"The article examines the processes of second harmonic generation (SHG) when selenium-metal (Cu) film structures are illuminated by femtosecond radiation (180 fs, 80 MHz) at wavelength 800 - 1000 nm. Selenium-copper structures were obtained by successive thermal evaporation of selenium and copper onto the glass substrate in vacuum. Microanalysis of the film composition was performed to determine amount of copper in thin films. The as-evaporated selenium-copper structures were crystallised by annealing in inert atmosphere at temperature 85°C. Just evaporated as well as annealed thin films were explored. The experiment was performed by confocal microscope [1] where the femtosecond radiation from laser was injected. A photosensitivity of structures in question was then determined as functions of intensity and wavelength of the incident radiation [2]. Second harmonic intensity dependence on thickness of Cu layer was also observed. We found out that adding small amount of Cu increases reflected SH intensity.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124438292","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}
Recently a number of organic and inorganic materials have been studied for direct surface-relief formation during the exposure process by a light or e-beam. It is very promising for practical application enabling the possibility to simplify the surface-relief formation technology. In this report the method of preparation of thin polymer-chalcogenide and polymer-azobenzene composite films is described, and some features of photoinduced changes of optical properties and holographic recording of these materials are studied. Films of composites were obtained from solution of arsenic sulphide, Disperse red 1 and polymers in organic solvents. The solution was spread on glass substrate and dried. The dry film thickness was in the range of 3-10 μm, with different correlation of arsenic sulphide, Disperse red 1 and polymers. The absorption spectres of these films was studied and described. The holographic recording of diffraction gratings was performed by different laser lines (442, 532 nm). During recording the diffraction efficiency was measured simultaneously in transmission and reflection mode. The profiles of the gratings and expositing area were analyzed by AFM microscope. Microanalysis of exposed and unexposed films showed a difference in chemical composition that can be explained by transfer of matter under the action of light.
{"title":"Holographic recording in polymer composites of organic photochromes and chalcogenides","authors":"A. Gerbreders, J. Teteris, V. Kolobjonoks","doi":"10.1117/12.815457","DOIUrl":"https://doi.org/10.1117/12.815457","url":null,"abstract":"Recently a number of organic and inorganic materials have been studied for direct surface-relief formation during the exposure process by a light or e-beam. It is very promising for practical application enabling the possibility to simplify the surface-relief formation technology. In this report the method of preparation of thin polymer-chalcogenide and polymer-azobenzene composite films is described, and some features of photoinduced changes of optical properties and holographic recording of these materials are studied. Films of composites were obtained from solution of arsenic sulphide, Disperse red 1 and polymers in organic solvents. The solution was spread on glass substrate and dried. The dry film thickness was in the range of 3-10 μm, with different correlation of arsenic sulphide, Disperse red 1 and polymers. The absorption spectres of these films was studied and described. The holographic recording of diffraction gratings was performed by different laser lines (442, 532 nm). During recording the diffraction efficiency was measured simultaneously in transmission and reflection mode. The profiles of the gratings and expositing area were analyzed by AFM microscope. Microanalysis of exposed and unexposed films showed a difference in chemical composition that can be explained by transfer of matter under the action of light.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"7142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129010818","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}
We report the optimization of a tunable source of near-infrared radiation based on a multigrating periodically poled lithium niobate (PPLN). The pump source for the PPLN optical parametric oscillator (OPO) was diode pumped Qswitched nanosecond Nd:YVO4 laser emitting the radiation at 1064 nm with the pulse repetition rate from 0.2 kHz to 40 kHz. The influence of the output-coupler and the resonator length on the efficiency of the PPLN OPO was investigated. For this aim eight mirrors with different reflectance were tested. A minimum threshold of 30 μJ was measured. The highest output power was 660 mW at 1.64 μm when the pump power was 3 W at 15 kHz pulse repetition rate. The bulk grating periods of the PPLN structure determined the signal in the range of 1.49-2.1 μm and idler in the range of 2.1-3.8 μm.
{"title":"High repetition rate optical parametric oscillator based on a periodically poled lithium niobate crystal pumped by nanosecond Qswitched Nd:YVO4 laser","authors":"L. Petravičiūtė, O. Balachninaitė, V. Sirutkaitis","doi":"10.1117/12.815644","DOIUrl":"https://doi.org/10.1117/12.815644","url":null,"abstract":"We report the optimization of a tunable source of near-infrared radiation based on a multigrating periodically poled lithium niobate (PPLN). The pump source for the PPLN optical parametric oscillator (OPO) was diode pumped Qswitched nanosecond Nd:YVO4 laser emitting the radiation at 1064 nm with the pulse repetition rate from 0.2 kHz to 40 kHz. The influence of the output-coupler and the resonator length on the efficiency of the PPLN OPO was investigated. For this aim eight mirrors with different reflectance were tested. A minimum threshold of 30 μJ was measured. The highest output power was 660 mW at 1.64 μm when the pump power was 3 W at 15 kHz pulse repetition rate. The bulk grating periods of the PPLN structure determined the signal in the range of 1.49-2.1 μm and idler in the range of 2.1-3.8 μm.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134618319","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}
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