Abstract:
PROBLEM TO BE SOLVED: To provide an optical fiber for decreasing optical fiber loss to the lowest level.SOLUTION: An optical fiber includes a silica-based core having a first dopant for selecting from a group comprising germania, fluorine and mixtures thereof as well as a second dopant containing an alkali metal oxide composed of KO in a peak concentration of 20-1,000 ppm. The concentration of the alkali metal oxide varies with a radius of the optical fiber. The concentration of the alkali metal oxide dopant in the core and a clad is properly selected so that the core has the refractive index profile which is the peak relative refractive index ΔMAX of more than 0.2% with the cladding.
Abstract:
PROBLEM TO BE SOLVED: To provide a low loss optical fiber and a method and an apparatus for manufacturing the same by appropriately selecting the concentration of alkali metal oxide dopant in a core and cladding.SOLUTION: There is provided the method for manufacturing the optical fiber in which a first glass rod is formed, having peak concentration of 20-1,000 ppm of alkali metal oxide comprising K0 and the first glass rod is inserted into a centerline hole of an optical fiber preform to form a composite preform.
Abstract:
A method for manufacturing a hermetically sealed package is provided, 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.
Abstract:
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 -0.5x10-4° C.-1 and -4.0x10-4 ° C.1 and an absorption coefficient of between 1.0 to 5.0 dB/cm at wavelengths between 980-1650 nm. The limiter also includes collimating fibers mounted on the input and output ends to minimize low power signal losses across the limiter body. It may be installed at a junction between two optical fibers and is preferably formed from a curable adhesive having the aforementioned negative thermal index coefficient to obviate the need for separate bonding materials and joining steps during the installation of the limiter. The optical limiter is reusable and with a recovery time of 1-5 milliseconds advantageously prevents power surges in optical circuits from damaging sensitive optical components by limiting the amplitude of such surges within 0.2-0.5 milliseconds.
Abstract:
An optical device (30) which utilizes a photothermal optical effect to achieve switching or attenuation includes a waveguide defined by a waveguide core (36) and a surrounding cladding (34), wherein the polymer waveguide core (36) includes a region (38) consisting of a photothermally responsive material having an absorption coefficient at a switch wavelength or attenuation wavelength that is higher than an absorption coefficient at a signal wavelength. Switching devices include an optical splitter circuit having a branch (36B) that includes the photothermally responsive material, and either a multiplexer for introducing light at the switch wavelength into the optical circuit or a light source (40) focused at the photothermally responsive material. Attenuating devices include a Mach-Zehnder type interferometer having a branch that includes the photothermally responsive material and either a multiplexer for introducing light at the attenuation wavelength into the optical circuit or a light source focused at the photothermally responsive material.
Abstract:
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 function of distance from the axis of the beam and a substantially constant width-wise intensity distribution. The elongated beam is traversed over a line of frit disposed between two substrates. The tails of the length-wise intensity distribution provide for a slow cool down of the frit as the beam traverses the line of frit.
Abstract:
A method and apparatus is provided for measuring the below 300nm internal transmittance of an optical material (12) comprising measuring the transmittance of a below 300nm light source (14) through at least two different pathlengths (16, 16') within a single sample of the material. The below 300nm light is transmitted through two opposing surfaces of the sample , the two opposing surfaces being spaced apart in a non-parallel relationship. The invention provides improved measurements for below 300 nm optical microlithography.