Abstract:
An active tap for use in an optical multiple access network. The tap comprises a semiconductor substrate (11) in which the electronics associated with an active parallel path are fully integrated. These include an optical detector (28), amplifiers (30) and a light emitter (29) formed using standard semiconductor fabrication techniques. A section of fiber (15), disposed within a groove (20) in the substrate, is provided with a pair of longitudinally spaced discontinuities (43, 44) for deflecting a portion of the incident signal onto the detector and for redirecting the output from the light emitter along the through-path.
Abstract:
An optical coupler and method of making thereof. The coupling ratio of the coupler is polarization-insensitive. The optical coupled described herein is made from single-mode optical fibers (12, 14). Each optical fiber has a length of nearly exposed core (20, 22) which is fused to the exposed core of the other optical fiber while the fibers are maintained in parallel juxtaposition with one another without twisting (24). By creating a fused core coupler from single-mode optical fibers in which the cores are in parallel juxtaposition with one another, the coupling ratio of the subject invention does not change with changes in polarization of light passing through each single-mode fiber and, thus, is polarization insensitive.
Abstract:
A crystalline fiber in which a core crystal fiber for transmitting infrared rays is provided in a cladding crystal pipe having a smaller refractive index than the core crystal.
Abstract:
A fiber optic data distribution system for transferring data between a plurality of terminals (72, 74, 76, 78). Each terminal is connected to a dedicated portion of separate fiber optical material (111a, 111b, 111c, 111d) and may be uniquely addressed by encoding the optical signal with a distinct address code. Optical signals may be supplied from a central processing unit (67) to one or more terminals (72, 74, 76, 78). Alternatively, an optical signal may be supplied by a terminal (72, 74, 76, 78) and transmitted to another terminal (72, 74, 76, 78), or the central processing unit (67).
Abstract:
An optical fiber is disclosed for operating single polarization, single-mode at wavelength λ. The fiber core (15, 21) is surrounded by cladding having the refractive index lower than the average refractive index of the core. The core is characterized in that it comprises a plurality of transparent laminae (16,17,23,24,31,32,37,38), each having a refractive index different from that of the adjacent laminae. The thickness of each lamina is equal to or less than wavelength λ.
Abstract:
Novel waveguides employing diacetylenes are present together with processes for their production. Such articles comprise diacetylenes and polymers formed from diacetylenic species, which polymers are amendable to close geometric, steric, structural, and electronic control. Accordingly, it is now possible to design formulate and employ new diacetylenic waveguideing polymers to provice non-linear optic, devices having surprising efficiencies. According to a preferred embodiment of the invention, diacetylenes which are crystallizable into crystals having a non-centro-symmetric unit cell may form single crystals or may be elaborated into a thin film upon a substrate by the Langmuir-Blodgett technique. Such films may, optionally, be polymerized either thermally or by irradiation for use. According to other preferred embodiments, diacetylenes are covalently bonded to substrates through the employment of silane species and subsequently polymerized to yield non- linear optic devices having high structural integrity in addition to high efficiencies and effects.
Abstract:
Single mode, single polarisation fibres are produced by the introduction of anisotropy into an optical fibre of otherwise arbitrary geometry and arbitrary but guiding refractive index profiles. The anisotropy, which may be induced by the application of transverse stress to the optical fibre, is sufficient to establish conditions under which one mode of linearly polarised light "leaks" from the fibre. In the case of step-profile optical fibres, having a core (10) and a cladding (11), the anisotropy may be such that one mode of propagation of light is completely eliminated from the fibre. Alternatively, in such fibres, the anisotropy may be such that the leakage of the unwanted mode from the fibre is gradual, so that the fibre effectively attenuates that mode, thereby eliminating the propagation of that mode when the fibre has a sufficient length.
Abstract:
An optical fiber tap which is especially useful as a node in a local area network, especially a ring topology local area network. The tap, which does not interrupt the physical continuity of the fiber, has an open position and a closed position. In the open position, a signal passing down the optical fiber (14, 122) passes through the tap without alteration. In the closed position, a signal passing down the optical fiber is extracted through a first bend (16) which is put into the fiber by the tap; the extracted signal, or an electrical counterpart thereof, is processed and a counterpart of the extracted signal, or a new signal obtained by operating on the extracted signal, e.g. in a data processor, is injected into the fiber through a second bend (24) which is put into the fiber by the tap. The tap may also contain an attenuator (32) between the signal extractor and injector, so that only that signal injected by the tap propagates down the fiber beyond the tap.
Abstract:
Wavelength filtering in the optical spectrums is accomplished by a fiber optics device mechanically separated from the device carrying the broad spectrum of wavelengths. The filter elements may be linear or loop shaped, and preferably utilize lateral coupling between fiber elements. Individual filter elements may be ganged for increased selectivity. The filters of the present invention have typical line widths of .01A.degree. to 1A.degree. in the .2 to 3 micron region.
Abstract:
Dispositifs optiques ayant des fibres optiques supportees de maniere rigide et leur procede de fabrication, ou une ou plusieurs fibres optiques (20, 26, 68, 78) sont en interface avec un materiau de support rigide (24, 30, 72, 74) par restructuration moleculaire des zones de la surface d'interface des fibres et du materiau de support. La fibre optique supportee de maniere rigide peut etre fabriquee en assemblant une portion de la surface exterieure longitudinale de la fibre (20, 26, 68, 78) en juxtaposition avec un materiau de support rigide (24, 30, 72, 74) ayant un point de fusion inferieur a celui de la fibre. Cet assemblage peut etre chauffe pour permettre un ramollissement partiel du materiau de support (24, 30, 72, 74) le long de la surface exterieure de la fibre (20, 26, 68, 78) pour permettre la fusion des deux. L'assemblage peut alors etre refroidi en ramenant sa temperature en dessous du point de fusion du materiau de support (24, 30, 72, 74) pour obtenir un assemblage a fibre optique consolide comprenant une fibre optique ayant fusionne avec un materiau de support rigide. Divers dispositifs optiques peuvent etre formes a partir de combinaisons de ces fibres optiques supportees de maniere rigide.