摘要:
A method for making an optical attenuating device comprising an optical waveguide having a core doped with a transition metal and a cladding. The transition metal is deposited in the core during a core blankmaking process. The transition metal doped core is exposed to gaseous hydrogen in a furnace to significantly increase the attenuation of the device.
摘要:
Optical waveguide core compositions comprising a core containing two dopants in a silica based glass, wherein one of the dopants is titania. The core composition serves to suppress the presence of Ti.sup.-3 and to preserve refractive index profile shape throughout the preform manufacturing process.
摘要:
A method for forming a GeO.sub.2 -doped SiO.sub.2 glass article by depositing glass particles to form a porous preform and then drying and sintering the porous preform. A precursor of SnO.sub.2 is also present in the reactant stream used to form the particles, whereby the reaction produces particles of glass that contain GeO.sub.2, SiO.sub.2 and SnO.sub.2. The presence of SnO.sub.2 in the particles reduces the reaction of GeO.sub.2 with chlorine to form GeCl.sub.4 during the drying step. The GeCl.sub.4 that would have formed would have either escaped from the porous preform or caused GeO.sub.2 to be re-deposited in an undesirable portion of the preform. The retention of GeO.sub.2 in the article is therefore enhanced.
摘要:
An optical fiber with a non-circular cross-section is realized by creating a void having the desired cross-section in a housing and filling the void with an optical material. This structure is then collapsed to solidify it and drawn to desired dimensions. The optical material may be rods, soot or ground material.
摘要:
This invention relates to production of high purity fused silica glass doped with titania through oxidation or flame hydrolysis of a gaseous mixture and containing rutile crystals comprising a vaporizable, silicon-containing compound. Titanium-2-ethylhexyloxide, titanium cyclopentyloxide, and a titanium amide, or a combination thereof, constitute the operable titanium-containing compounds.
摘要:
An achromatic fiber optic coupler of the type wherein first and second single-mode optical fibers, each having a core and a cladding, are fused together along a portion of the lengths thereof to form a coupling region. A matrix glass of lower index than the fiber claddings surrounds the coupling region. The fiber diameters are smaller in the coupling region than in the remainder of the fibers. The refractive index n.sub.2 of the cladding of the first fiber is different from the refractive index n.sub.2 ' of the cladding of the second fiber, the difference between the refractive indices n.sub.2 and n.sub.2 ' being such that the coupler exhibits very little change in coupling ratio with wavelength over a band of wavelengths.
摘要:
An optically-active air-clad fiber (30) includes a core (34, 84) that facilitates doping with an ion optically excitable and having a three-level optical transition when pumped at a first end (28) of an optical cavity (46) by a multimode pump source (72) at a pump wavelength (64) for lasing at a signal wavelength (66) different than the pump wavelength (64) at a second end (29) of the optical cavity (46), the core (34, 84) having a refractive index, wherein the core (34, 84) is transformed from the first end to proximate the second end (29) thereof such that the optically-active fiber (30) is multimode at the pump wavelength proximate to the first end (28), and is single-mode at the signal wavelength proximate to the second end (29). An air-clad (36, 86) surrounds at least one portion of the core (34, 84) and has a lower effective refractive index than the refractive index of the core (34, 84).
摘要:
This invention relates to production of high purity fused silica glass doped with titania using titanium chelates. Useful chelates include titanium acetylacetonate, and titanium ethyl acetoacetate among others.
摘要:
A single mode optical waveguide fiber having low, non-zero dispersion over a pre-selected wavelength range is disclosed. The refractive index profile of the core is characterized in that the core includes a plurality of distinct regions, each having an index profile, and a radius or width. By adjusting the index profile sizes and shapes of the plurality of core regions, a waveguide fiber may be made having a set of properties tailored for a high performance telecommunication system. In particular, dispersion slope can be maintained less than 0.05 ps/nm.sup.2 -km and absolute magnitude of total dispersion maintained in the range of 0.5 to 3.5 ps/nm-km over a pre-selected wavelength range. The zero dispersion wavelength is outside the pre-selected wavelength range and the cut off wavelength and mode field diameter are controlled to target values.
摘要:
Disclosed is a mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d. The modifier comprises a modifier core having a refractive index n.sub.1. Surrounding the modifier core is first cladding layer having a refractive index n.sub.2 that is less n.sub.1. On the surface of the first cladding layer is a second cladding layer having a refractive index n.sub.3 which is less than n.sub.2. The modifier is tapered intermediate its ends whereby it has a large diameter end and a small diameter end. The diameters of at least the core and first cladding layer at the large diameter end are greater than the corresponding diameters at the small end. The diameter D.sub.1 of the first cladding layer at the large diameter end is greater than d. An axially disposed hole in the large diameter end receives a fiber which is held in such alignment with the mode field modifier that it is in light coupling relationship with the modifier core. The mode field of a signal coupled from the fiber to the mode field modifier expands as it propagates though the tapered portion of the modifier to the small diameter end. An in-line coupler between two optical fibers is effected by connecting together in axial alignment two such mode field modifiers with their small diameter ends adjacent one another.