Stephan Logunov

Corning Incorporated | Corning

We report the results of fabricating fiber array unit (FAU) connectors using a near IR laser welding process, locking fibers in proper position on planar glass substrates and forming strong glass-to-glass bonds, followed by final assembly using lower coefficient of thermal expansion (CTE) epoxies. A thin metal film deposited on the glass substrate...

We report a quasi single-mode fiber setting an absolute low attenuation record of 0.1400 dB/km at 1560 nm or 0.1407 at 1550 nm. The fiber core is silica-based, doped with halides (Cl, F) and an alkali oxide (K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O). This core composition, along with...

Assemblies, optical connectors, and methods for forming fiber arrays using laser bonded optical fibers are disclosed. In one embodiment, a method of forming a fiber array includes placing an optical fiber on a surface of a substrate, directing a laser beam into the optical

A flow reactor for photochemical reactions comprises an extended flow passage (20) surrounded by one or more flow passage walls (22), the flow passage having a length and a light diffusing rod (30) having a diameter of at least 500 μm and a length, with at least a portion of the length of the rod (30) extending inside of and along the flow passage...

This paper describes a novel fiber designed to produce uniform illumination in angular space along its length. The mechanism of light extraction from the silica glass guiding region is due to nano-sized gas filled voids formed during fiber preform consolidation and fiber draw process. The resulting effect creates an aesthetically pleasing line or s...

Background and objectives: Hospital-acquired infections (HAIs) and multidrug resistant bacteria pose a significant threat to the U.S. healthcare system. With a dearth of new antibiotic approvals, novel antimicrobial strategies are required to help solve this problem. Violet-blue visible light (400-470 nm) has been shown to elicit strong antimicrob...

Despite their transformative role in our society, oxide glasses remain brittle. Although extrinsic post-processing techniques can partially mitigate this drawback, they come with undesirable side effects. Alternatively, topological engineering offers an attractive option to enhance the intrinsic strength and damage resistance of glass. Based on thi...

A method of sealing a workpiece comprising forming an inorganic film over a surface of a first substrate, arranging a workpiece to be protected between the first substrate and a second substrate wherein the inorganic film is in contact with the second substrate; and sealing the workpiece between the first and second substrates as a function of the...

Glasses with compressive stress profiles that allow higher surface compression and deeper depth of layer (DOL) than is allowable in glasses with stress profiles that follow the complementary error function at a given level of stored tension. In some instances, a buried layer or local maximum of increased compression, which can alter the direction o...

A method for sealing a liquid within a glass package and the resulting sealed glass package are described herein where the sealed glass package can be, for example, a dye solar cell, an electro-wetting display or an organic emitting light diode (OLED) display.

Fiber-based cylindrical light diffusers are often used in photodynamic therapy to illuminate a luminal organ, such as the esophagus. The diffusers are often made of plastic and suffer from short diffusion lengths and low transmission efficiencies over a broad spectrum. We have developed FibranceTM, a glass-based fiber optic cylindrical diffuser whi...

Disclosed is an optical fiber having a core with an alkali metal oxide dopant in an peak amount greater than about 0.002 wt. % and less than about 0.1 wt. %. The alkali metal oxide concentration varies with a radius of the optical fiber. By appropriately selecting the concentration of alkali metal oxide dopant in the core and the cladding, a low lo...

A sealing device and method are described herein that can be used to manufacture a hermetically sealed glass package. In one embodiment, the hermetically sealed glass package is suitable to protect thin film devices which are sensitive to the ambient environment (e.g., oxygen, moisture). Some examples of such glass packages are organic emitting lig...

Light diffusing optical fibers for use in ultraviolet illumination applications and which have a uniform color gradient that is angularly independent are disclosed herein along with methods for making such fibers. The light diffusing fibers are composed of a silica-based glass core that is coated with a number of layers including a scattering layer...

An illuminated color display panel having at least one light diffusing waveguide, and a transparent panel having at least one luminophore provided in a predetermined pattern on at least one major planar surface of the transparent panel is provided. Light from at least one light source is coupled to the waveguide and light from the waveguide is coup...

An illuminated color display panel having at least one light diffusing waveguide, and a transparent panel having at least one luminophore provided in a predetermined pattern on at least one major planar surface of the transparent panel is provided. Light from at least one light source is coupled to the waveguide and light from the waveguide is coup...

Light diffusing optical fibers for use in illumination applications and which have a uniform color gradient that is angularly independent are disclosed herein along with methods for making such fibers. The light diffusing fibers are composed of a silica-based glass core that is coated with a number of layers including both a scattering layer and a...

Light diffusing optical fiber bundles, illumination systems including light diffusing optical fiber bundles, and methods of affixing light diffusing optical fiber bundles to polymer optical fibers are disclosed. A light diffusing optical fiber bundle includes an optically transmissive jacket and a plurality of light diffusing optical fibers dispose...

Vacuum-insulated glass (VIG) windows (10) that employ glass-bump spacers (50) and two or more glass panes (20) are disclosed. The glass-bump spacers are formed in the surface (24) of one of the glass panes (20) and consist of the glass material from the body portion (23) of the glass pane. Thus, the glass-bump spacers are integrally formed in the g...

A light-diffusing element with high coupling efficiency to LED sources. The light-diffusing element may be a glass monolith that includes a plurality of internal voids. When light propagating through the monolith encounters the internal voids, it is scattered in a transverse direction and exits the lateral surface of the monolith to provide a broad...

Light diffusing optical fibers for use in ultraviolet illumination applications and which have a uniform color gradient that is angularly independent are disclosed herein along with methods for making such fibers. The light diffusing fibers are composed of a silica-based glass core that is coated with a number of layers including a scattering layer...

Light-coupling systems and methods that employ light-diffusing optical fiber are disclosed. The systems include a light source and a light-diffusing optical fiber optically coupled thereto. The light-diffusing optical fiber has a core, a cladding and a length. At least a portion of the core comprises randomly arranged voids configured to provide su...

Depth-sensitive fluorescent spectroscopy can be executed by directing UV radiation through a face of a laminated glass sheet to induce distinct fluorescence in respective target layers of the laminated glass sheet. The respective target layers define glass compositions and relative indices of refraction that permit formation of an externally-viewab...

Vacuum-insulated glass (VIG) windows (10) that employ glass-bump spacers (50) and two or more glass panes (20) are disclosed. The glass-bump spacers are formed in the surface (24) of one of the glass panes (20) and consist of the glass material from the body portion (23) of the glass pane. Thus, the glass-bump spacers are integrally formed in the g...

An illumination system that includes at least one light-diffusing optical fiber is disclosed. The illumination system includes at least one low-scatter light-conducting optical fiber that optically couples the at least one light-diffusing optical fiber to at least one light source. The light-diffusing optical fiber includes a light-source fiber por...

Disclosed is an optical fiber having a core with an alkali metal oxide dopant in an peak amount greater than about 0.002 wt. % and less than about 0.1 wt. %. The alkali metal oxide concentration varies with a radius of the optical fiber. By appropriately selecting the concentration of alkali metal oxide dopant in the core and the cladding, a low lo...

Systems and methods for coupling light into a transparent sheet. The systems include a light source and a light-diffusing optical fiber optically coupled to the light source. The light-diffusing optical fiber has a core, a cladding and a length, with at least a portion of the core comprising randomly arranged voids configured to provide substantial...

Light-coupling systems and methods that employ light-diffusing optical fiber are disclosed. The systems include a light source and a light-diffusing optical fiber optically coupled thereto. The light-diffusing optical fiber has a core, a cladding and a length. At least a portion of the core comprises randomly arranged voids configured to provide su...

Borosilicate glass swelling by laser irradiation is an unusual phenomenon. The height of raised hemisphere on the swelled glass surface can be approximately 10–15% of the 1–3 mm glass thickness. To understand the mechanism of glass swelling, the micro-structural information of swelled glasses is essential. Several transmission electron microscopy (...

Light diffusing optical fibers and methods for producing light diffusing optical fibers are disclosed. In one embodiment, a light diffusing optical fiber includes a core portion formed from silica glass and comprising a plurality of helical void randomly distributed in the core portion of the optical fiber and wrapped around the long axis of the op...

Raised features are formed on a transparent substrate having absorption of less than about 20% within a processing wavelength range. A portion of the substrate is irradiated with a light beam to increase the absorption of the irradiated portion of the substrate. Continued irradiation causes local heating and expansion of the substrate so as to form...

The paper reviews optical fibers with nano-engineered features and methods to fabricate them. These optical fibers have nano-engineered regions comprising of randomly distributed voids which provide unique properties for designing next generation of fibers. Discussion of impact of void morphology on fiber optical properties is presented, along with...

An illumination system generating light having at least one wavelength within 200 nm to 2000 nm range. The system includes a light source and at least one light diffusing optical fiber with a plurality of nano-sized structures (e.g., voids). The optical fiber is coupled to the light source. The light diffusing optical fiber has a core and a claddin...

We describe the design of thin, ~ 100-180 micron diameter, optical silica fibers for illumination. The fiber has a silica core with specially engineered scattering centers to scatter light through walls of the fiber across a wide wavelength range

Packages for elements, e.g., OLEDs, that are temperature sensitive are provided. The packages have a first glass substrate (12), a second glass substrate (16), and a wall (14) that separates the first and second substrates (12,16) and hermetically seals at least one temperature sensitive element (18,28,36) between the substrates (12,16). The wall (...

An illumination system generating light having at least one wavelength within 200 nm a plurality of nano-sized structures (e.g., voids). The optical fiber coupled to the light source. The light diffusing optical fiber has a core and a cladding. The plurality of nano-sized structures is situated either within said core or at a core-cladding boundary...

Systems and methods for performing photoreactions in a photoreactive material using scattered actinic light from at least one light-diffusing optical fiber are disclosed. The systems and methods include disposing a light-diffusing optical fiber relative to the photoreactive material. The light-diffusing optical fiber has a glass core, a surrounding...

A method for manufacturing a hermetically sealed package is provided, the method comprising the steps of: using a laser to heat a frit, disposed in a pattern between two substrates, such that the heated frit forms a hermetic seal which connects the substrates and further comprising: directing the laser to enter the frit pattern, then to trace the f...

Analysis of laser assisted frit sealing processes for high CTE > 5x10-6/°C (coefficient of thermal expansion) glasses was done. The method is based on the thermal fusion of two glasses with a low melting point glass frit. This method is used when thermal sensitive materials such as OLED (organic light emissive device) are present in the glass packa...

A laser assisted frit sealing method is described herein that is used to manufacture a glass package having a first glass plate (with a relatively high CTE of about 80-90.times.10.sup.-7.degree. C..sup.-1), a second glass plate, and a frit (with a CTE that is at least about 35.times.10.sup.-7.degree. C..sup.-1), where the frit forms a seal (e.g., h...

We describe the process of forming bumps on the surface of transparent glasses such as display glasses with moderate thermal expansion ∼3.2 × 10−6 K−1 and high coefficient of thermal expansion (CTE) glasses, e.g. soda-lime glasses with CTE ∼9 × 10−6 K−1 using high-power ultra-violet (UV) lasers at a wavelength where glass is transparent. We charact...

Packages for elements, e.g., OLEDs, that are temperature sensitive are provided. The packages have a first glass substrate (12), a second glass substrate (16), and a wall (14) that separates the first and second substrates (12,16) and hermetically seals at least one temperature sensitive element (18,28,36) between the substrates (12,16). The wall (...

Glass frit seal with localized heating using near infrared laser can provide long-term hermeticity and good mechanical strength for OLEDs. In this report, some general characteristics of the frit sealing process are first discussed. Then the impacts offrit and glass substrate properties, such as CTE and strain points on the seal, will be presented....

A glass article having at least one edge of which at least a portion has been laser melted. The laser melted portion scatters light, thus enabling the glass article to be properly aligned. In some embodiments, the laser melted portion also provides a roughened edge having a coefficient of friction that facilitates handling of the glass article. The...

We describe a novel process of laser-assisted fabrication of surface structures on doped oxide glasses with heights reaching 10 - 13% of the glass thickness. This effect manifests itself as a swelling of the irradiated portion of the glass, and occurs in a wide range of glass compositions. The extent of such swelling depends on the glass base compo...

This paper reviews a technology for making nano-engineered optical fibers. Key features and advantages of nano-enginneered glass fibers are discussed. Fiber designs and their applications are presented.

Optical fibre coating degradation under high power is directly linked to power dissipated in the bend. Bend insensitive fibres have much weaker heating response to the same input power in the bend than more bend sensitive fibres. Fibre lifetime predictions under high power and bending also are impacted by fibre deployment and the properties of coat...

A method of encapsulating a display device between substrates with a glass frit. The method includes depositing a frit having an optical absorption .alpha. which is a function of wavelength onto a first substrate wherein the deposited frit has a height h, placing a second substrate in contact with the frit, sealing together the substrates by traver...

Methods are provided for laser patterning a partial depth surface portion of a glass body by controlling the amount of stress induced in the glass body. A laser beam is directed along an impinged path on the surface portion of the glass body to heat the glass body to form a swell. The glass body is then cooled and etched. The surface portion of the...

A method of minimizing stress in an OLED device laser sealing process using an elongated laser beam. A laser beam having an intensity distribution which decreases as a function of distance from the longitudinal axis of the beam is passed through a mask to create an elongated beam having a length-wise intensity distribution which decreases as a func...

Laser writing of waveguides in bulk glasses opens the opportunity for creating three-dimensional photonic devices. In order to become practical, the numerical aperture (NA) of these waveguides should be significantly higher than currently achievable of 0.1 - 0.15. One reason is that with higher NAs one can decrease the bending radii of the embedded...

We describe a novel process of laser-assisted fabrication of surface structures on doped oxide glasses with heights reaching 10 – 13% of the glass thickness. This effect manifests itself as a swelling of the irradiated portion of the glass, which occurs in a wide range of glass compositions. The extent of such swelling depends on the glass base com...

Microlenses are formed on a substrate having a first absorption within an operational wavelength range, and a second absorption outside the operational wavelength range, wherein the second absorption is greater than the first absorption. One or more waveguides are coupled with a processing light beam having a wavelength outside the operational wave...

Glass-based micropositioning systems and methods are disclosed. The micropositioning systems and methods utilize microbumps (40) formed in a glass substrate (12 or 100). The microbumps are formed by subjecting a portion of the glass substrate to localized heating, which results in local rapid expansion of glass where the heat was applied. The heigh...

A hermetically sealed glass package and method for manufacturing the hermetically sealed glass package are described herein. In one embodiment, the hermetically sealed glass package is suitable to protect thin film devices which are sensitive to the ambient environment. Some examples of such glass packages are organic emitting light diode (OLED) di...

Picosecond absorption spectroscopy was used in a study of stabilization of a primary ion-radical pair P +I − in reaction centers of purple bacteria Rb. sphaeroides. Measurements were made on samples with hydrogen bonds modified by isotopic substitution of H2O with D2O and by introduction of cryoprotectors into the structure of the reaction centers....

A method is proposed for monitoring the relative change in the duration of picosecond pulses. This method is based on second harmonic generation. It is shown that selecting pulses according to their duration in an absorption spectrometer raises the accuracy of recording of the kinetic curve and increases the time resolution of this method. The lase...

A method of minimizing localized heating of, or minimizing signal losses across a source of loss in, an optical fiber used in transmission of a high power optical signal at an operating wavelength. These methods include the steps of: providing an optical fiber which comprises either (i) a coating characterized by an absorbance of less than about 4....

A new technique to monitor germanium oxygen deficiency centre defects (GeODC) and their relation to the refractive index profile in Ge-Si optical fibre have been developed. This method is based on UV excited luminescence of GeODC in silica based optical fibres. The GeODC defect profiles are unique to the fibre refractive index (profile of GeO<sub>2...

As optical fiber penetrates further into the communications in- frastructure and comes closer to the home or business, higher optical power levels are expected. Several studies have shown that sharply bent optical fiber will fail prematurely when ex- posed to high optical power levels. In an extreme case, where the fiber is bent to a maximum bend s...

Optical fiber networks are being developed that require higher optical power levels. Examples include long haul communication with Raman amplification and fiber to the premises. Previous studies indicate that tightly bent optical fiber can mechanically fail when exposed to high optical power levels. In an extreme case where fiber is sharply bent an...

A variety of different types of light scattering (Rayleigh, Brillouin, Raman, and Mie scatterings), which may contribute to the transmission losses in the bulk of high-quality CaF2 monocrystals, have been investigated experimentally and theoretically. The angular distribution of Rayleigh and Mie scatterings in the visible spectral range has been me...

The invention provides an ultraviolet lithography method/system. The lithography method and system include providing a below 200 nm radiation source, providing a photolytically improved transmitting fused silica glass lithography optical element, transmitting below 200 nm photons through said photolytically improved transmitting fused silica glass...

We have systematically analyzed the excess scattering in a relatively large index optical fiber operating in the single mode regime. A mathematical model based on the theory of scattering of plane waves from a randomly perturbed core-clad interface is presented that predicts excess scattering confined within a small angle in the forward direction....

A bridge fiber and a method of connecting two other dissimilar optical waveguide fibers is presented. The bridge fiber may be utilized to connect positive dispersion fibers or step index single mode fibers to compensative fibers, such as dispersion compensation fibers or dispersion-slope compensation fibers.

Glasses in the Ca--Al--Si system are useful in forming optical components for use in telecommunication systems. The glasses include, in mole percent: SiO.sub.2 present in an amount of about 6 to about 60 percent, Ga.sub.2 O.sub.3, Al.sub.2 O.sub.3, or a combination thereof present in an amount of about 12 to about 31 percent, and CaO present in an...

The correlation between chemical effects of some typical optical fiber coating formulations and adhesion to glass was studied by the use of laser spallation. The technique was able to show verifiable differences between dissimilar materials and demonstrated a good correlation to adhesion values determined by mechanical peel testing, and to pullout...

In this paper we present the result of a sensitive experimental technique used to provide information about the limitations of using organic polymers for fiber-optic high power applications. Optical path adhesives are commonly used in fiber optics assemblies due to their mechanical and optical properties. However, their use in high power applicatio...

The failure of tightly bent optical fiber under high optical power is observed dynamically with fine time resolution and explained in terms of the behavior of the polymer coating and underlying glass. An abrupt rise in coating temperature stimulates the viscoelastic deformation of the glass. The abrupt bending of the glass is explained by the abili...

The heating effect in highly bent single-mode optical fibres under high power conditions was studied. It was found that heating of the coating depends on the bend radius and the type of telecommunication fibre used. The detected heating only occurred at bend diameters much smaller than that recommended for normal deployment.

We describe the performance of a fiber-optic power-limiting component. The passive device is dynamically responsive to the input signal and has been shown to attenuate continuous-wave power with a dynamic range of up to 9 dB at 150 mW of input power at 1550 nm. The limiting threshold is approximately 30 mW from 1530 to 1565 nm and less than 10 mW a...

Scattering losses for fused silica were measured over a wide wavelength range (193-800 nm) using different laser sources. The data indicate that scattering centers are smaller than ~ 12 nm, and scattering is consistent with Rayleigh type even at 193 nm. Scattering losses scale with wavelength as 1/lambda4, and scattering loss at 193 nm was found to...

A double frequency overtone of the fundamental NH bond related vibration was found to dominate the optical loss in the 1.5–1.6 μm range in high index GeSiON-based planar waveguides deposited by plasma-enhanced chemical vapor deposition using hydrogen-based precursors. The fundamental NH bond-related absorption and its double frequency overtone we...

An optical signal limiter is provided for limiting transmission of a continuous wave optical signal that exceeds a preselected threshold power level. The limiter includes a body having input and output ends that is formed at least in part from a material having a negative thermal index coefficient of between about -0.5.times.10.sup.-4 .degree.C..su...

An accelerated radiation damage testing method for an optical sample includes disposing the optical sample inside or external to an optical cavity and injecting a predetermined number of light pulses into the optical cavity at a selected wavelength and at spaced intervals. Each light pulse injected into the optical cavity produces a train of pulses...

A theoretical and experimental study of photothermal behavior in a commercially available optical path adhesive is described. Photothermal effects were examined for cw and pulsed laser radiation (∼1 µs) at 1550 nm. A fiber-optic backreflection technique was used to measure the thermo-optic glass transition temperature of the adhesive. This transiti...

We present the results of two-pump and probe femtosecond experiments designed to follow the relaxation dynamics of the lowest excited state (S(1)) populated by different modes. In the first mode, a direct (S(0) --> S(1)) radiative excitation of the ground state is used. In the second mode, an indirect excitation is used where the S(1) state is popu...

The method of cavity ringdown spectroscopy (when a tunable pulsed optical parametric oscillator was used) was extended for the loss evaluation in thin films (2–20-µm thickness). The technique was applied in two key telecommunication wavelength ranges of 1260–1330 and 1480–1650 nm. The measurement sensitivity was determined to be 50 ppm (5 × 10⁻⁵)....

form only. Three experimental approaches for detection of optical losses in thin films for the telecommunication wavelength region are discussed. These techniques are cavity ring down spectroscopy, photothermal and propagation loss methods. Results for thin film loss evaluation in various applications are shown.

It was previously found that by removing the negative charge of Asp85 in bacteriorhodopsin (bR), either by protonating it (as in deionized bR) or by mutation to Asn, the decay time of the retinal excited state increases from 0.5 ps to either 1.5 or 10 ps. The two decay components result from the presence of all-trans and 13-cis,15-syn (13-cis) reti...

Using time-resolved optical hole (oh)-burning techniques with femtosecond lasers, the time dependence of the spectral diffusion of the oh is examined for both the CdS quantum dot (QD) and the CdS/HgS/CdS quantum dot quantum well (QDQW) nanoparticles. It is found that the nonradiative relaxation of the optical hole is at least 3 orders of magnitude...

The relaxation dynamics of charge carriers in 4 nm CdS colloidal quantum dots are studied by means of picosecond time-resolved fluorescence and femtosecond transient absorption experiments. We also studied the effects of the adsorption of viologen derivatives as electron acceptors on the surface of these particles. From these experimental measureme...

Retinal photoisomerization dynamics are studied at both room temperature and 20 K in wild-type bacteriorhodopsin using femtosecond pulses. We were able to resolve the decay at 20 K into two components with the dominant component having a similar lifetime to that observed at room temperature. This strongly suggests that the retinal lifetime at physi...