Abstract:
Disclosed is an optical waveguide fiber preform which is an assembly of one or more core rods (14) surrounded by a plurality of clad rods (10). The clad rods (10) have a central portion (12) and a surrounding layer (22), in which the refractive index of the central portion is lower than that of the surrounding layer. The preform is drawn into an optical waveguide fiber that has a two component clad layer. Proper choice of the central portion (12) and surrounding layer provide a waveguide fiber that is endlessly single mode. Alternative embodiments include fibers containing dopants that enhance fiber photosensitivity or which provide stress-induced or asymmetric-refractive-index-induced birefringence in the waveguide fiber.
Abstract:
A method of writing a light guiding structure (26) in a bulk glass substrate (4) including selecting a bulk glass substrate (4) made from a soft silica based material. An excimer laser beam (5) is focused at a focus point (3) within the substrate while translating the focus relative to the substrate along the scan path. The laser beam (5) is moved at a scan speed so as to induce an increase in the refractive index of the material along the scan path relative to that of the unexposed material, while at the same time incurring very little laser induced breakdown of the material along the scan path. Various optical devices, including waveguides, can be made in this way.
Abstract:
Stress-induced photoelastic birefringence compensates for intrinsic birefringence of cubic crystalline structures (12) in deep ultraviolet (less than 200 nm) microlithographic imaging systems (10). Both the photoelastic birefringence and the intrinsic birefringence are expressed in a tensor format simplified by the symmetries of cubic crystalline structures. The stress-induced photoelastic birefringence can be sized to individually compensate for intrinsic birefringence exhibited in the same optical elements or preferably to collectively compensate for the cumulative effects of intrinsic birefringence in other optical elements in the lithography system.
Abstract:
A method of determining parameters of plurality of thermal cycles to achieve a set glass strain level includes providing a plurality of input parameters for a glass substrate and a plurality of parameters for a plurality of thermal cycles. The method also includes iteratively modifying at least one of the pluralities of thermal cycle parameters so the glass strain is not greater than the set glass strain level after a final thermal cycle is completed. An aspect of the method usefully enables a user to determine from the material parameters and processing sequences of the glass manufacturer and further entities that may further process the glass (e.g., the glass manufacturer's customers) whether a particular glass strain can be achieved; and if not the example embodiments allows the manufacturer to calculate changes in the customers' processes to meet the desired glass strain.
Abstract:
The invention relates to fused silica having low compaction under high energy irradation, particularly adaptable for use in photolithography applications.
Abstract:
An isotopically-altered, silica based optical fiber is provided having lower losses, broader bandwidth, and broader Raman gain spectrum characteristics than conventional silica-based fiber. A heavier, less naturally abundant isotope of silicon or oxygen is substituted for a lighter, more naturally abundant isotope to shift the infrared absorption to a slightly longer wavelength. In one embodiment, oxygen-18 is substituted for the much more naturally abundant oxygen-16 at least in the core region of the fiber. The resulting isotopically-altered fiber has a minimum loss of 0.044 dB/km less than conventional fiber, and a bandwidth that is 17 percent broader for a loss range between 0.044-0.034 dB/km. The fiber may be easily manufactured with conventional fiber manufacturing equipment by way of a plasma chemical vapor deposition technique. When a 50 percent substitution of oxygen-18 for oxygen-16 is made in the core region of the fiber, the Raman gain spectrum is substantially broadened.
Abstract:
The invention provides a method of making a crystal direction of the optical calcium fluoride crystal. In a preferred embodiment, the below 194 nm transmitting optical element is a oriented calcium fluoride lens. In a preferred embodiment, the below 194 nm transmitting optical element is a oriented calcium fluoride beam splitter.
Abstract:
The present invention includes a composite optical waveguide fiber. The composite optical waveguide fiber includes a first optical waveguide fiber. The first optical waveguide fiber has a first diameter and a first outermost layer having a first coefficient of thermal expansion. The composite optical waveguide fiber further includes a second optical waveguide fiber coupled to the first optical waveguide fiber. The second optical waveguide fiber has a second diameter and a second outermost layer, the second outermost layer having a second coefficient of thermal expansion. Wherein the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion. Wherein the first diameter is greater than the second diameter.
Abstract:
An active photonic crystal device for controlling an optical signal is disclosed. The device includes a planar photonic crystal (100) with a defect waveguide (102) bounded on the top and bottom by an upper cladding region (106) and a lower cladding region (104). An optical signal propagating in the defect waveguide (102) is confined in the plane of the photonic crystal (100) by the photonic bandgap, and in the direction normal to the photonic crystal (100) by the upper clad region (106) and the lower clad region (104). The propagation of the optical signal in the defect waveguide (102) is controlled by varying the optical properties at least one of the upper clad region (106) or the lower clad region (104). The variation of the optical properties of the controllable regions may be achieved using a thermo-optic effect, an electro-optic effect, a stress-effect, or a mechano-optic effect, or by moving a material into or out of the controllable region.