0000000001185206
AUTHOR
Janis Teteris
Absorption and luminescence in amorphous SixGe1-xO2 films fabricated by SPCVD
Abstract Optical absorption and photoluminescence of Ge-doped silica films fabricated by the surface-plasma chemical vapor deposition (SPCVD) are studied in the 2–8 eV spectral band. The deposited on silica substrate films of about 10 μm in thickness are composed as x·GeO2-(1-x)·SiO2 with x ranging from 0.02 to 1. It is found that all as‐deposited films do not luminesce under the excitation by a KrF (5 eV) excimer laser, thus indicating lack of oxygen deficient centers (ODCs) in them. After subsequent fusion of silicon containing (x
Holographic recording in amorphous chalcogenide semiconductor thin films
Abstract A detailed study of the amorphous As–S–Se and As2S3 films as recording media for optical holography and electron beam lithography is presented. The results of R&D on resist based on the amorphous As–S–Se thin films for manufacturing of embossed holographic labels are discussed. The holographic recording of transmission and Bragg gratings was studied.
Impact of fluorine admixture, hydrogen loading, and exposure to ArF excimer laser on photoluminescence of bismuth defects in amorphous silica
Abstract Photoluminescence (PL) excited by ArF (193 nm), KrF (248 nm) and N 2 (337 nm) pulsed lasers is studied in bismuth doped unfused silicon dioxide synthesized on silica substrates by surface-plasma chemical vapor deposition (SPCVD). Additive free and fluorinated (F content ~ 0.4 wt.%) amorphous silica are examined as host materials for bismuth. Three typical PL bands peaking at wavelengths of 650 nm (orange), 800 nm and 1400 nm (near infrared, NIR) were observed. It is found that fluorine additive weakly affects PL detail of as deposited samples. However, hydrogen loading completely deactivates NIR PL in the case of fluorine free sample, but only slightly suppresses the NIR band in fl…
<title>Holographic recording in amorphous chalcogenide semiconductor photoresists</title>
The properties and mechanism of relaxation processes of holographic gratings in amorphous chalcogenide semiconductor films have been studied. The possibilities of the practical applications of these materials as the photoresists for the production of the relief holograms and holographic optical elements are discussed. It is shown that the self- enhancement phenomenon of holographic recording in amorphous chalcogenide semiconductor films by light or thermal treatment can be used to increase the diffraction efficiency of the holograms.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Azodyed gelatin films for holographic recording
Abstract In this work we present a preparation method of azo-dyed gelatin thin films for holographic recording and their photoinduced changes of optical properties. The non-toxic, commercially available and cheap ingredients were used for film preparation. The films were prepared by mixing azo-dyes with gelatin solution. The photoinduced properties of prepared films were investigated. The photoinduced dichroism and birefringence at 532 nm laser radiation were observed. The holographic recording of surface and volume gratings by 532 nm wavelength laser radiation were performed and surface relief gratings were studied with AFM. The mass transport direction in azodyed gelatin was studied.
<title>Holographic recording of subwavelength structures in amorphous chalcogenide thin films</title>
Holographic recording of surface-relief and refiactive-index-modulated gratings with a period ranging from 0.15 to 1 μm in thin amorphous chalcogenide films of As-S-Se and As2S3 is studied. The profile of the surface-relief gratings is measured by atomic force microscopy. By structuring the As-S-Se films with the subwavelength-period surface-relief gratings their reflectivity is decreased from 25-30% to less than 2%. In the refractive-index-modulated As2S3 films polarization effects are revealed. It is shown that the angular selectivity of the holographic recording in amorphous chalcogenide thin films can be substantially improved by decreasing the grating period.© (2005) COPYRIGHT SPIE--Th…
Optical Field-Induced Mass Transport in Soft Materials
Abstract The dependence of the surface relief formation in amorphous chalcogenide (As 2 S 3 and As-S-Se) and Disperse Red 1 dye grafted polyurethane polymer films on the polarization state of holographic recording light beams was studied. It is shown that the direction of lateral mass transport on the film surface is determined by the direction of light electric vector and photoinduced anisotropy in the film. We propose a photoinduced dielectropfhoretic model to explain the photoinduced mass transport in amorphous films. Model is based on the photoinduced softening of the matrix, formation of defects with enhanced or decreased polarizability, and their drift under the electrical field gradi…
Direct Surface Relief Formation in Polymer Films
Due to active development of nanoelectronics, the studies of methods of nanorelief surface formation in different materials, in particular polymers are very important. Organic polymer films in consequence of their dielectric and optical properties have been used as basis of these devices. In this paper, the possibility of UV optical record and electron beam lithography in different type of polymeric films was studied. Mechanisms of molecular structure changes: photoisomerization, destruction, cross-linking and oxidation have been discussed. The results of UV illumination of polyurethanes, polyacrylates, and some block-copolymers were described. The element analysis of polybutadiene block co…
Photoinduced mass transport in low molecular organic glasses and its practical application in holography
Abstract In this paper we present the synthesis and optical properties of amorphous low molecular compound 4-((4-(bis(5,5,5-Triphenylpentyl)amino)phenyl)diazenyl)benzoic acid. The surface relief gratings formation by polarization holography method on these thin films (thicknesses are 200–1700 nm) was shown. The dependence of the surface relief modulation on various parameters: recording exposure dose, the polarization state of the recording beams, the grating period and the film thickness of the material was demonstrated. Values of surface tension at the air-film before and after irradiation of the substance by polarized radiation were measured. The efficiency of surface relief formation in…
<title>Amorphous chalcogenide semiconductor resists for holography and electron-beam lithography</title>
The photo- and electron beam induced changes in solubility of amorphous chalcogenide semiconductor As-S-Se and As2S3 thin films have been studied. The possibilities of practical application of these materials as resists for the production of relief holograms and holographic optical elements are discussed. It is shown that the self-enhancement phenomenon of holographic recording in amorphous chalcogenide semiconductor films by light or thermal treatment can be used to increase the diffraction efficiency of the holograms.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Investigations of As-S-Se thin films for use as inorganic photoresist for digital image-matrix holography
AbstractAs-S-Se chalcogenide thin films are successfully employed in classical and dot-matrix holography as inorganic photoresists for obtaining a relief-phase hologram. However using these films for image-matrix hologram recording has not been studied due to some features of image-matrix technology. For the applied research of the optical properties of As-S-Se films an experimental device of digital image-matrix holographic recording based on 100 mW 405 nm semi-conductor laser and Spatial Light Modulator (SLM) has been created. The device has the following main parameters: 140 × 105 µm frame size; laser intensity during exposure 10 W/cm2. With the help of this device diffraction grating an…
Photosensitive properties of composite films based on copper chloride in polymer matrix
The composite films based on PMMA and CuCl2 were prepared. Transmission spectra of the films before and after illumination by different laser lines (405, 448, 456 nm) were measured. The reversible character of the composite photosensitivity was fixed. The phenomenon of direct surface relief formation after laser beam illumination of composite films was described. The holographic gratings were recorded by different exposure (200 – 500 J/cm2) in the films with different concentration (8 and 20 wt. %) of copper salt. The film sensitivity dependence on polymer molecular weight was studied. Surface relief of the gratings was measured by AFM.
Photosensitive polyurethanes for optical record
The method of synthesis of photosensitive polyurethanes polymers on glycerine, toluenediisocyanate and Disperse Red 1 base has been described. Two types of polymers with different amount of Disperse Red 1 fragments in macromolecules were compared. Films of the polymers were obtained from solutions in organic solvents on glass substrate. The dry film thickness was in the range of 3,5 - 4.5 μm. The transmission spectrums of the films were studied. Possibility of formation of side product in the process of synthesis was observed. The photobirefringence measurements of polymers films were performed. Surface relief grating (SRG) formation was observed during polarization holographic recording pr…
LUMINESCENCE STUDY OF DETERGENT OPTICAL BRIGHTENERS IN THE CONTEXT OF DEVELOPING OPTICAL ENVIRONMENTAL SENSORS FOR WATER QUALITY CONTROL
Water quality and anthropogenic loads in many, but not all, cases are related. Some water quality monitoring programs analyse samples for the presence of Escherichia coli. These bacteria can come from humans and animals. Human‐attributable effluent contains optical brighteners (OBs) from detergents. A convenient and affordable optical quantitative method giving a linear luminescence outcome over several orders of detergent concentrations in the water solution is demonstrated. The proposed method uses the common presence of OBs in detergents. Detergent concentration in water can be used as a surrogate indicator of resultant anthropogenic loads in water bodies. The proposed optical method wit…
<title>Dot-matrix holographic recording in amorphous chalcogenide films</title>
We have developed PC controlled dot-matrix holographic recording system based on the CW diode pumped YAG:Nd SHG laser (wavelength 532 nm, power 30mW,) modulated electronically with TTL signals. Two-beam technique has been used with convergence angle 30o and PC controlled incident beam plane rotation 0-360o. Optical system consists of beam splitter, 40mm focus length forming cylindrical lens and 40mm focusing lens. Characteristic parameters of experimental equipment are following: spot size - 50-200 micrometers, direct laser writing area, limited by x-y positioning system, was 70mm x 70mm, number of writing head rotation positions up to 256 (8 bit), time of each exposure - 1-1000 msec. As th…
<title>Holographic recording in amorphous chalcogenide semiconductor thin films</title>
ABSTRACT The photoinduced changes ofoptical properties and holographic recording in amorphous chalcogenide semiconductor As-S- Se and As2S3 thin films have been studied. The possibilities of the practical applications of these materials as the photoresists for the production of the relief holograms and holographic optical elements are discussed. It is shown that theself-enhancement phenomenon of holographic recording in amorphous chalcogenide semiconductor films by light orthermal treatment can be used to increase the diffraction efficiency ofthe holograms.Keywords: chalcogenide semiconductors, amorphous films, photoresists, photoinduced processes, relaxation processes,self-enhancement of h…
Photoinduced direct surface relief formation in amorphous As40S15Se45 films
Abstract The surface relief grating formation in As40S15Se45 films under He–Ne laser wave-length λ = 0.6328 μm light influence was examined. The obtained experimental results showed the strong dependence of photoinduced surface relief depth on illumination dose and film thickness during holographic recording from film side as well as from glass substrate side. The surface relief grating profile over the thickness range 0.13
Photosensitivity of SiO2–Al and SiO2–Na glasses under ArF (193 nm) laser
Abstract Photosensitivity of SiO 2 –Al and SiO 2 –Na glass samples was probed by means of the induced optical absorption and luminescence as well as by electron spin-resonance (ESR) after irradiation with excimer-laser photons (ArF, 193 nm). Permanent visible darkening in the case of SiO 2 –Al and transient, life time about one hour, visible darkening in the case of SiO 2 –Na was found under irradiation at 290 K. No darkening was observed at 80 K for either kind of material. This investigation is dedicated to revealing the electronic processes responsible for photosensitivity at 290 and 80 K. The photosensitivity of both materials is related to impurity defects excited directly in the case …
Photoinduced mass transfer in amorphous As 2 S 3 films
The surface relief grating formation in amorphous As2S3 films strongly depends on the polarization state of recording beams. The surface relief grating formation efficiency of s-s and p-p recording beam combination can be essentially enhanced by additional illumination with orthogonal polarization. It is shown that the direction of mass transport on the film surface is determined by the direction of light electric vector (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced mass transport in amorphous As‐S‐Se films
Direct surface patterning due to photoinduced mass transport in amorphous As-S-Se films has been studied. Illumination of the films with two orthogonally (±45°) polarized beam interference pattern causes the formation of surface relief gratings on the films due to lateral mass transport regarding to light propagation direction. The obtained experimental results showed the dependence of photoinduced surface relief depth (Δh) on film thickness during holographic recording from film side as well as from glass substrate side. After constant exposure doses for the films with a thickness d 1 μm values of Δh do not depend significantly on the film thickness for recording from film side but decreas…
<title>Photo-induced structural changes in near-surface layers of chalcogenide semiconductors</title>
Photoinduced structural changes in near-surface layers of amorphous As-Se and As-S films have been investigated using the microhardness method. Microhardness via indentation depth data for as-deposited, illuminated and aged in ambient atmosphere films is presented. The results obtained show that photoinduced increase in microhardness of surface layers up to approximately 1 - 1.5 micrometer are more pronounced in comparison with deeper layers. Increase in microhardness of the investigated films under exposure to atmosphere was also observed. Atmosphere-induced effect was more pronounced in the case of As-S films. Photo- and atmosphere-induced effects in the near-surface layers were found to …
Photoinduced mass transport in azo compounds
The photoinduced changes of optical properties in azobenzene containing compound thin films were studied under influence of polarized and non-polarized 532 nm laser light. Under influence of light azo compounds experience trans-cis isomerisation process, that can be observed in the absorbance spectrum of the sample. If the light is linearly polarized, molecules align perpendicularly to the electric field vector and as a result photoinduced dichroism and birefringence is obtained. If a known lateral polarization modulation of the light beam is present, mass transport of the azobenzene containing compound occurs. By measuring the surface relief with a profilometer the direction of mass transp…
On thermal influence of laser beam irradiation on optical absorption of amorphous as-evaporated As2S3 films
Abstract Photoinduced changes of the optical absorption in amorphous as-evaporated As 2 S 3 thin films are studied. Before the measurements films were kept at dark for more than two years. The long storage time ensured that the relaxational structural changes caused by the deposition process were absent. As a light source a CW unfocused 488.0 nm Ar laser line was used. The intensity of the laser beam was varied from rather low intensity values up to intensities which raised the temperature of the films above the glass transition temperature. Based on the behavior of the saturation values of the absorption we were able to state that the exposed As 2 S 3 films started to polymerize at 63–69°C…
Optical grating recording in ChG thin film by electron beam
Abstract Recording capabilities of As Se S chalcogenide (ChG) glasses using electron beam (EB) lithography have been investigated in this study. After exposure with EB the thin films of these inorganic glasses can be etched in alkaline amine solvent with high selectivity. High resolution, smooth shaped structures have been fabricated using ChG thin films. Height of developed pattern can be controlled through changing applied electron dose.
Optical Properties of Composite Films Based on Copper Chloride in PMMA Matrix
The composite lms based on PMMA, CuCl2 and photoinitiator were prepared.Transmission spectra of the lms with and without photoinitiator were measured. The holo-graphic gratings were recorded, the sensitivity of the lms and surface structure of gratingswere studied. Microanalysis of the lms was performed in di erent part of structure elementsof grating.
Surface relief grating recording in azo polymer films
In this work holographic recording of surface relief grating in organic Poly(Disperse Red 1 – methacrylate) thin films was studied. In this compound azo dye is chemically bonded to monomers making mass transport very efficient in the presence of optical field gradient. Sample preparation was performed using different solvents and coating methods. In the obtained samples holographic recording was performed by solid-state diode pump laser with 532 nm wavelength. Polarization grating and surface relief grating formation was studied by diode laser with 660 nm wavelength. Diffraction efficiency's dependence on read-out laser beam polarization state was investigated. The depth of surface relief g…
<title>Bragg and asymmetric-relief reflection gratings in As-S-Se thin films</title>
Bragg and asymmetric-relief gratings and their formation in the amorphous As-S-Se films are discussed. Due to the high refractive index and its photoinduced change, the films are useful in holography. The thickness of the As0.4S0.15Se0.45 and As0.4S0.3Se0.3 films used in the Bragg gratings is optimized. The dependence of the dimaction efficiency of the asymmetric-relief gratings on the conditions of recording, chemical treating, and reading out (polarization and angle) is studied.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Optinių baliklių skalbimo priemonėse liuminescencijos tyrimas siekiant sukurti optinius aplinkosauginius vandens kokybės kontrolės jutiklius
Water quality and anthropogenic loads in many, but not all, cases are related. Some water quality monitoring programs analyse samples for the presence of Escherichia coli. These bacteria can come from humans and animals. Human-attributable effluent contains optical brighteners (OBs) from detergents. A convenient and affordable optical quantitative method giving a linear luminescence outcome over several orders of detergent concentrations in the water solution is demonstrated. The proposed method uses the common presence of OBs in detergents. Detergent concentration in water can be used as a surrogate indicator of resultant anthropogenic loads in water bodies. The proposed optical method wit…
Second harmonic generation in selenium-metal structures
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 fr…
Surface relief formation in amorphous chalcogenide thin films during holographic recording
Abstract This report present the studies of direct holographic recording of the surface relief gratings on amorphous As2S3 films by 532 nm laser light. By giving extra time for recording exposure (more than necessary for volume amplitude-phase optical recording, e.g. Kikineshi, 2000 [2] ), changes of surface relief in the resist material can be observed. This direct surface relief formation phenomenon during holographic recording is discussed here from the side of recording light polarization. Efficiency of the relief formation may also depend on softening temperature of the film material and this influence was studied as well by using additional incoherent light for extra exposure during r…
Surface relief grating formation in amorphous As40S15Se45 and As2S3 films under 0.532 μm wavelength illumination
In this research we have studied the influence of λ = 0.532 μm laser light illumination on the formation and properties of surface relief gratings in amorphous As2S3 and As40Se15Se45 films, as well as a bulk As2S3 sample. The surface relief grating formation was studied for a wide range of grating periods (∼1 – ∼80 μm) for the variable thicknesses of the samples. The examination of the relief depth, Δh, and its dependence on the grating period at constant exposures shows that the impact of sample thickness could manifest itself as a shift in the optimal grating period at holographic surface relief formation (As2S3) and affect the process itself.
Holographic Recording of Surface Relief Gratings on As40S60-xSex Thin Films
The studies of direct holographic recording of the surface relief gratings on amorphous As40S60−xSex thin films are presented. These gratings were created upon exposure to polarized laser beams of various wavelengths (λ = 473 – 650 nm). The orthogonally ±45° linearly polarized light beams were used for recording. The surface structure of the relief gratings was investigated by atomic force microscopy. The influence of laser beam wavelength and spatial frequency of the gratings recorded (grating period ?) on the surface relief gratings formation for every composition was examined.
Photoinduced mass transport in soft materials
The surface relief grating formation in amorphous As2S3 and azo-benzene polymer films strongly depends on the polarization state of recording beams. The surface relief grating formation efficiency of s-s and p-p recording beam combination can be essentially enhanced by additional illumination with orthogonal polarization. It is shown that the direction of mass transport on the film surface is determined by the direction of light electric vector.
Application of amorphous chalcogenide thin films in optical recording technologies
A solid immersion holographic method for the recording of refractive-index and surface-relief modulated gratings with a period of 0.2 µm–1 µm in amorphous films of chalcogenide semiconductors As2S3 and As-S-Se has been developed and studied. The angular selectivity of holographic recording in amorphous chalcogenide thin films can be improved significantly by a decrease of grating period. The possibility to use the amorphous chalcogenide films as a media for holographic recording and storage of information with high density is discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarization holographic recording in Disperse Red1 doped polyurethane polymer film
In this report holographic recording of polarisation and surface relief gratings in Disperse Red 1 (DR1) doped polyurethane polymer films was studied. In this material DR1 is chemically bounded to polyurethane polymer main chain. Polarization holographic recording was performed by two orthogonal circularly polarized 532 nm laser beams. Photoinduced birefringence is a precondition for polarization holograms recording, therefore a detailed study of a photoinduced birefringence and changes of optical properties was performed. The lasers with wavelengths of 375nm, 448nm, 532 nm and 632.8 nm were used as pumping beam for sample excitation. The photoinduced birefringence Δn was measured at 532 nm…
Intra-center and recombination luminescence of bismuth defects in fused and unfused amorphous silica fabricated by SPCVD
Abstract Photoluminescence (PL) of bismuth doped silicon dioxide excited by UV excimer lasers (ArF — 193 nm, KrF — 248 nm) and a green light laser diode (532 nm) is studied in a wide spectral band at temperatures ranging from 12 to 750 K. Two types of samples are investigated: unfused, 100 μm in thickness amorphous layer immediately deposited on the inner surface of silica substrate tube, and the same material after profusion resulted from tube collapsing to a rod by external heating. PL bands centered at 620–650 nm, 820 nm and 1400 nm wavelengths are observed in both fused and unfused samples. Under excitation by the green laser diode decay time constants for 650 nm (orange) and 1400 nm (N…
Azobenzene Containing Low-Molecular Weight Organic Glasses for Optical Recording
Abstract In this work photoinduced processes and holographic surface relief formation in azobenzene containing low- molecular weight organic glasses were studied. The molecular glasses due to trans-cis isomerisation and photo- orientation of molecules possess high sensitivity to the light irradiation and therefore they are promising media for holographic recording. Electric field of linearly polarized light causes an alignment of molecule dipoles perpendicularly to the electric field vector and this process is accompanied by an appearance of photoinduced optical anisotropy in organic glasses. The photoinduced birefringence and dichroism induced by 532 nm light was studied. Holographic recor…
<title>Amorphous chalcogenide thin films as a media for holographic recording</title>
The amorphous As2S3 and As40S15Se45 films as a recording media for optical holography and lithography were studied. The results on research of the transmission, surface-relief and Bragg reflection grating holographic recording and readout conditions are presented. The recording of transmission holographic gratings in As40S15Se45 films was performed by He-Ne (0.6328 μm) laser beam, while the redout of the diffraction efficiency was made at Bragg agle using diode (0.805 μm) laser lines. The Bragg reflection gratings in As2S3 films were recorded and studied by Ar+ laser line 0.5145 μm. The surface-relief modulated gratings with a period of 0.15 μm - 1 μm were recorded.© (2004) COPYRIGHT SPIE--…
<title>Holographic recording in polymer composites of organic photochromes and chalcogenides</title>
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. …
Holographic recording in amorphous chalcogenide thin films
Abstract Holographic recording by He–Ne laser (line 632.8 nm) light in amorphous As 0.55 Se 0.45 thin films for different film thickness and grating period was studied. A strong dependence of the diffraction efficiency of the gratings on the readout light wavelength (650 nm, 805 nm and 1150 nm) was observed. A decrease in diffraction efficiency for longer wavelengths is explained by a decrease in the photoinduced changes of refractive index. It is shown that high efficiency gratings can be recorded in As 0.55 Se 0.45 films with a thickness of ∼1 μm.
UV optical record and electron beam lithography in polymer films
Possibility of UV optical record and electron beam lithography in different type of organic polymer films was studied. Mechanisms of molecular structure changes: photoisomerization, destruction, cross-linking and oxidation have been discussed. The results of UV illumination of polyurethanes, polyacrilates, and some block-copolymers are described. The element analysis of polyisoprene block copolymer was performed before and after UV illumination, and the changes in transmission spectra of the polymer film were measured. The resolution of electron beam lithography on polymer films was studied. In the polyisoprene block copolymer film the oxidation polymerization was ascertain at UV-illuminati…
<title>Amorphous As-S-Se films for holographic recording</title>
The amorphous As40S15Se45 films as recording media for optical holography were studied. The results on research of transmission and Bragg grating holographic recording and readout conditions are presented. The recording of transmission holographic gratings was performed by He-Ne (0.6328 μm) or Kr+ (0.6764 μm) laser beam, while the readout of the diffraction efficiency was made at Bragg angle using He-Ne (0.6328 and 1.15 μm) or diode (0.805 μm) laser lines. It is shown that self-enhancement of Bragg grating reflectors is possible. The influence of thin film interference conditions on holographic recording parameters is demonstrated.© (2003) COPYRIGHT SPIE--The International Society for Optic…
<title>Application of amorphous chalcogenide thin films in optical recording technologies</title>
A review of the recent advances and developments in the practical application of amorphous chalcogenide materials is presented, focusing special attention to holography and lithography. The main functional principles and practical application of amorphous chalcogenide photoresists for production of the embossed rainbow holograms and holographic optical elements are discussed. The laser interference lithography can be used as a low-cost method for the exposure of large surfaces with regular patterns like subwavelength-gratings and microsieves. The surface-relief and reftactive-index modulated gratings with a period of about 50 nm and less can be fabricated by immersion holographic method. Th…
Optical method for determining optical brightener concentration in water solution
The field of environmental sensors has been developing driven by the Baltic Sea environmental considerations. The authors propose the use of optical methods for developing sensitive, selective and low cost approach to address water media emitted matter research. An optical method to detect the human anthropogenic load presence in water bodies by measuring minute optical brighteners (OBs) concentration in water due to the laundry effluent is demonstrated. The authors propose to use OBs as a conveniently and affordably detectable optical parameter to compare the levels of human impact on the water bodies studied.
<title>Relaxation processes in amorphous As-S and As-Se films</title>
The relaxation of optical, mechanical and chemical properties of as-evaporated amorphous As-S and As-Se films while storing them at room temperature is investigated. The AsxS1-x films with arsenic content 0.3 less than x less than 0.4 are found to undergo maximal changes. It is shown that the phenomenon of dark self-enhancement of holograms (an increase of diffraction efficiency over time without any special treatment) can be used as an efficient method for investigation of relaxation processes in the amorphous chalcogenide films. The changes of diffraction efficiency in amorphous As2S3 films have been measured as a function of aging time and recording light intensity. The relaxation proces…
Ultraviolet holographic recording in photopolymers
Norland Optical Adhesive (NOA) acrylate based photopolymers were studied as a medium for Bragg grating fabrication. NOA photopolymers have absorption maximum in near UV region, but they are transparent in visible light region. Photopolymers were irradiated by He-Cd laser 325 nm line interference patterns during holographic recording. In light irradiated regions photopolymerization takes place and volume grating can be recorded. Diffraction efficiency in dependence on sample thickness, recording beams polarization state and intensity was investigated on transmission mode. Enlargement of sample thickness allows to achieve better angular selectivity of diffracted beam, therefore thickness of p…
<title>Investigation of As<formula><inf><roman>2</roman></inf></formula>S<formula><inf><roman>3</roman></inf></formula>-Al films for dot-matrix holographic recording</title>
We have performed the investigation of dot matrix holographic recording in amorphous As2S3 chalcogenide films with different thickness on Al coated glass substrates. The control over the interference minimum of reflection during the evaporation process allowed obtaining As2S3-Al system with a minimum value of initial reflection in defined spectral region. The investigation of dependence of diffraction efficiency of holographic recording on both film thickness and initial conditions of reflectivity in the system was performed. The main advantage of this type of system is the possibility to increase optical sensitivity of material in predefined spectrum region for phase hologram recording.© (…
Holographic recording optimization in amorphous As-Se-S films
The holographic recording parameters of amorphous chalcogenide semiconductor (AChS) thin films under optimization depend on hologram type. So, using self-enhancement effect during recording and wet etching after recording enable possibility to decrease recording energy and increase of signal/noise ratio for embossed holograms. Choosing the appropriate light exposure permit us to achieve equal values of diffraction efficiency (DE) for different diffraction orders during fabrication of light splitting holographic optical elements (HOE). Changing film thickness and recording wavelength it is possible to find optimal conditions for high DE holographic gratings readable at infrared region of lig…
<title>Relief holographic recording in amorphous As-S-Se</title>
The relief-phase holographic gratings in amorphous As-S-Se thin films were recorded and studied. The holographic recording was performed by He-Ne laser (0.6328 μm). The influence of etching and cohernet self-enhancement processes on the formation of surface relief in amorphous As-S-Se thin films was studied.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Optical-field induced volume- and surface-relief formation phenomenon in thin films of vitreous chalcogenide semiconductors
In this report the study of direct recording of the surface relief gratings on amorphous chalcogenide thin (2.5-5μm) films is presented by three different recording setups. Recording was performed on As2S3 by 532nm wavelength laser light. Additionally the evolution of surface relief in dependence from the recording time and polarization has been investigated in detail. The mechanism of the direct recording of surface relief on amorphous chalcogenide films based on the photo-induced plasticity has been discussed.
Enhancement of photosensitivity in azo-epoxy resists for direct holographic recording
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/7 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged”
Luminescence of unfused 95%SiO2–5%GeO2 amorphous films with fluorine additive: No evidence for presence of GeODC(I) defects found
Abstract Photoluminescence (PL) of unfused amorphous germanosilicate films with fluorine additive is studied in 2–8.5 eV spectral range. Experiments are based on films deposited on silica substrates by means of the surface-plasma chemical vapor deposition (SPCVD). Films of about 100 μm in thickness with “high F” (~ 4.2 wt.%) and “low F” (~ 0.5 wt.%) fluorine content have been fabricated for the experiments. KrF (248 nm), ArF (193 nm) and F2 (157 nm) excimer lasers are used to pump PL. It is found that absorption and luminescence associated with germanium oxygen deficient centers (GeODCs) in “high F” and “low F” films differ. In the “high F” unfused film absorption coefficient of the band at…
Amorphous As–S–Se semiconductor resists for holography and lithography
Abstract The photo- and electron-beam induced changes in solubility of thin films of the amorphous chalcogenide semiconductors As–S–Se and As 2 S 3 have been studied. The possibilities of practical application of these materials as resists for the production of relief holograms and holographic optical elements are discussed. It is shown that the self-enhancement (SE) phenomenon of holographic recording in amorphous chalcogenide semiconductor films by light or thermal treatment can be used to increase the diffraction efficiency (DE) of the holograms.
Holographic recording in amorphous chalcogenide thin films
A review of the recent advances and developments in the practical application of chalcogenide materials is presented, focusing special attention on holography and lithography using amorphous chalcogenide thin films.
<title>Indentation creep and stress relaxation in amorphous As-S-Se and As-S films</title>
The indentation creep in as-deposited and photopolymerized As- S-Se and As-S films has been investigated. The results show pronounced relaxation of mechanical stresses in the films at room temperature. The relationship (sigma) equals B (epsilon) m between the deformation rate and the stress is observed and the values of the deformation rate sensitivity exponent m < 1 are found. The creep rate was found to be dependent on deposition conditions of layers, applied indentation load, structural state of the material and light irradiation during the creep test.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.