摘要:
A method of modifying birefringence properties of a waveguide formed within a carrier, the method comprising the steps of inducing a stress anisotropy in the waveguide and effecting a differential decrease in a first refractive index of one mode in the waveguide with respect to a second refractive index of another mode of the waveguide.
摘要:
A method of creating an optical filter for selectively filtering an optical signal transmitted through the filter, the method comprising: constructing a Bragg grating in an optical element coupled to an optical path way for the transmission of the optical signal to suppress background radiation; and adjusting the coupling so as to produce a selective transmission spectrum in according with predetermined requirements.
摘要:
Various technologies and techniques are disclosed that relate to providing interactive television by synchronizing content to live and/or recorded television shows. Content is synchronized without the use of in-band triggers. A broadcast stream is received, and search/action pairs are received from a transmission path, such as from the Internet or user. When the search criteria are found in the broadcast stream, the associated action is performed and the content is synchronized with the show. An application programming interface is used to facilitate synchronization, and includes a set search method, a search function template method, and a clear search method. The set search method initiates searching of the broadcast stream and registers one or more callback methods for performing the associated action when the match is found. The search function template serves as the template for registering the callback methods. The clear search method clears the system resources from the search.
摘要:
An optical fiber being optically transmissive at a predetermined wavelength of light λ and comprising a plurality of coaxial layers. Each layer having an optical path length that varies radially, the coaxial layers being arranged to give the fiber a refractive index profile which, in use, causes sufficient Fresnel diffraction of the light such that it is guided in the fiber. The refractive index of a cladding region (60) is intermittently suppressed by controlling heating of the preform tube, thus forming a chirped saw-tooth profile (70). The optical fiber may include a lens. In this case, each of the layers has an optical path length that increases gradually outwardly by substantially n×λ/2 (n: integer).
摘要:
The invention relates to a method of producing a preform for a holey optical fiber, and more particularly, to a method of producing polymer holey optical fiber using novel capillary and cane designs that allow a construction of complex holey structures. The capillaries may have a complex internal structure including multiple holes, holes of non-circular shape, off-center holes, holes of different sizes, or any combination of these. The canes may have a complex external shape to define interstitial holes when the canes arc combined in a stack (see FIG. 1). The capillaries and canes may be made of different materials and combined within the same structure.
摘要:
A method of creating an optical structure within a photosensitive light transmissive material comprising the steps of: (a) exposing a selected region of the material to radiation at a wavelength selected to effect a refractive index change in the material; (b) terminating the exposure to the radiation at a selected fluence; and afterwards (c) exposing at least one portion of the selected region to UV radiation at a level sufficient to vary the refractive index of the material within the selected region to form the optical structure; wherein the fluence is selected such that the optical structure is substantially thermally stable without a requirement for post-processing annealing.
摘要:
This invention relates to a method of preparing a preform for an optical fibre, and more particularly to a method of preparing a preform for a polymer holey optical fibre. The invention provides a method of preparing a preform for manufacture of a polymer holey optical fibre comprising casting a preform body in a mould from a suitable material, said mould including at least one protrusion adapted to form a corresponding hole within the preform, and subsequently separating the preform body and mould. The invention also provides a method of preparing a preform for manufacture of a polymeric holey optical fibre comprising separately casting one or more elements of a preform in respective mould(s) from a suitable material, and separating said elements from said respective mould(s) and combining said elements to construct a preform having a plurality of holes therein, each hole being formed in an element or formed by the combination of two or more elements.
摘要:
A method of thermally poling a silica based waveguide (12) comprises exposing a region of the waveguide (12) to an electric field (for example, via capillary electrodes (22, 24) inserted into holes in the waveguide); directing a laser beam (18) into the region exposed to the electric field to effect localized heating of the region via direct absorption; and scanning the laser beam (18) over the region at a rate selected to avoid heating of the region above the glass transition temperature. Reversing the electric field while scanning the laser beam (18) allows the formation of periodic poled gratings. The waveguide (12) can comprise an optical fiber.
摘要:
An optical waveguide (1) has a grating structure (2) in which gratings of different orders are superimposed. When first and second order gratings are superimposed, input light is partially reflected by the first order component and partially coupled out of the waveguide by the second order component. The second order component can also be used to couple external light into the waveguide (1). The grating structure (2) has applications to free space couplers, optical sensors, and suppression of ripples in dispersion compensators.
摘要:
A single longitudinal mode narrow linewidth and low threshold all fiber laser arrangement is disclosed, constructed from a ring cavity, a gain portion in the ring cavity, an input-output coupling interposed within the cavity and pumping means connected to the ring cavity and to the grating such that, upon actuation of the pumping means, the arrangement acts as a laser.