摘要:
The invention relates to method and apparatus for transmitting an optical signal having optical energy substantially in a high order spatial mode. The optical waveguide, in one embodiment, includes a few mode fiber designed to have specific transmission characteristics for supporting the single high order spatial mode, and the few mode fiber transmits the single high order spatial mode. The optical waveguide, in one embodiment, has a dispersion and a dispersion slope for a given transmission bandwidth. Another aspect of the invention includes a method for transmitting an optical signal having optical energy substantially in a single high order spatial mode. The method includes the steps of providing a few mode fiber, which supports optical energy in the single high order spatial mode. In one embodiment, the single high order spatial mode is the LP02 spatial mode In another embodiment, the few mode fiber supports an optical signal having optical energy having less than twenty spatial modes.
摘要:
An optical waveguide supporting a plurality of modes including an absorbing annulus which attenuates a desired mode to a lesser degree than any other mode in the plurality of modes. In one embodiment, the absorbing annulus is disposed in the core of the waveguide. In another embodiment, the annulus is concentric about the core. In another embodiment, the annulus has a predetermined width and radius. In yet another embodiment the desired mode includes the LP02 mode.
摘要:
An optical waveguide supporting a plurality of modes including an annulus which attenuates a desired mode to a lesser degree than any other mode in the plurality of modes. In one embodiment, the annulus is disposed in the core of the waveguide. In another embodiment, the annulus is concentric about the core. In another embodiment, the annulus has a predetermined width and radius. In yet another embodiment the optical waveguide includes an annulus that is disposed at a radial position corresponding to a region in the core in which the desired mode has substantially no energy. In yet another embodiment the desired mode includes the LP02 mode. In another embodiment, the annulus includes a scattering material. In still another embodiment, the annulus includes a conductive dopant material. Another embodiment includes a sharp change of refractive index within the core. Still other embodiments include disposing a region of increased refractive index in the core of the waveguide to attenuate undesired modes. Another embodiment includes disposing a region of decreased refractive index in the core of the waveguide to attenuate undesired modes. Other embodiments include combinations of annuli. These combinations of annuli can include, for example, absorbing annuli, scattering annuli, annuli comprising conductive dopant material, regions of increased refractive index, and regions of decreased refractive index or any combination thereof.
摘要:
The invention relates to apparatus and methods for transforming a spatial mode of an optical signal. The apparatus includes an optical phase element for imparting a predetermined spatially selective phase delay to the optical signal, and a mask in optical communication with the optical phase element. The mask, in one embodiment, includes an optically attenuating region disposed in a predetermined spatial pattern. In one aspect of the invention, the optical signal is transformed from a first spatial mode to a second spatial mode. In another aspect of the invention, the mask includes an absorbing material arranged in a predetermined spatial pattern. In yet another aspect of the invention, the mask includes a scattering material arranged in a predetermined spatial pattern. The invention also relates to a method for transforming a spatial mode of an optical signal. The method includes the step of receiving the optical signal having a first spatial mode with an intensity distribution and a phase. The method further includes the steps of selectively spatially attenuating the intensity distribution of the first spatial mode of the optical signal, selectively spatially delaying the phase of the optical signal, and propagating the selectively spatially attenuated and delayed optical signal. The first spatial mode of the optical signal is substantially transformed into a second spatial mode.