Abstract: A heating device for an optical fiber may include a crucible body having an optical fiber receiving slotted passageway therein for receiving the optical fiber therein, and a heating element receiving passageway therein adjacent the optical fiber receiving slotted passageway and spaced apart therefrom. The heating device may include a respective electrically powered resistance heating element enclosed within the heating element receiving passageway for heating the optical fiber within the optical fiber receiving slotted passageway.

Abstract: An apparatus and method for tapering an optical fiber segment having an initial radial profile to substantially conform to a pre-specifiable desired radial profile for controlling mutually coordinated elongation and softening of different axial portions of the segment according to control parameters derivable based on a normalized axial coordinate reference by which points of the initial profile map to corresponding points of the desired profile. The softening and/or elongation may progress substantially in either a step-wise, time-discrete manner or time-continuously. The invention is useful for forming tapered fused couplers as well as for tapering individual fibers.

Abstract: A heating device for an optical fiber may include a crucible body having an optical fiber receiving slotted passageway therein for receiving the optical fiber therein, and a heating element receiving passageway therein adjacent the optical fiber receiving slotted passageway and spaced apart therefrom. The heating device may further include a respective electrically powered plasma heating element enclosed within the heating element receiving passageway for heating the optical fiber within the optical fiber receiving slotted passageway.

Abstract: A heating device for an optical fiber may include a crucible body having an optical fiber receiving slotted passageway therein for receiving the optical fiber therein, and a heating element receiving passageway therein adjacent the optical fiber receiving slotted passageway and spaced apart therefrom. The heating device may include a respective electrically powered resistance heating element enclosed within the heating element receiving passageway for heating the optical fiber within the optical fiber receiving slotted passageway.

Abstract: An apparatus and method for tapering an optical fiber segment having an initial radial profile to substantially conform to a pre-specifiable desired radial profile for controlling mutually coordinated elongation and softening of different axial portions of the segment according to control parameters derivable based on a normalized axial coordinate reference by which points of the initial profile map to corresponding points of the desired profile. The softening and/or elongation may progress substantially in either a step-wise, time-discrete manner or time-continuously. The invention is useful for forming tapered fused couplers as well as for tapering individual fibers.

Abstract: A filled-core optical fiber (100) spliced to conventional, solid core optical transmission fiber (175) and a related method of making the same are provided. The optical fiber (100) comprises a core region (140), a cladding ring (120) enclosing the core region (120), and an outer cladding layer (160). A fill hole (115) is formed in the optical fiber (100) which extends from an outer sidewall (110) to the core region (140). The fill hole (115) is for introducing optical material (165) into the core region (140). The optical material (165) is introduced into the core region (140) after opposing ends (121, 122) of the optical fiber (100) are spliced to the free ends (176, 176) of conventional, solid core optical transmission fiber (175). The optical material (165) is introduced into core region (140) after splicing to avoid damage to the optical material (165) due to exposure to high temperatures generated during splicing.

Abstract: A four-port optical filter is provided including two tapered optical fibers, each having a loop in the area of their tapered portions, which are located relative to one another to form a ring resonator. The optical filter has a low Q with a broadband filter response which is useful as a channel interleaver or de-interleaver for dense wavelength division multiplexing and other applications.

Abstract: A method and apparatus is provided for measuring the spatial temperature distribution of a flame emitted from a burner nozzle for use in the fabrication of tapered optical fibers and fused couplers so that the position of the burner can be calibrated to locate the optical fiber within the most thermally stable part of the flame during production.

Abstract: A four-port optical filter is provided including two tapered optical fibers, each having a loop in the area of their tapered portions, which are located relative to one another to form a ring resonator. The optical filter has a low Q with a broadband filter response which is useful as a channel interleaver or de-interleaver for dense wavelength division multiplexing and other applications.

Abstract: A suite of optical performance monitoring (OPM) methods, based on optical subcarrier multiplexing, are described by the invention. The strength of this approach lies in the simplicity of double sideband subcarrier signals and the fact that these signals travel the complete optical path with the baseband signal of interest. The subcarrier signals can be recovered using techniques described in the application and are immune to fiber dispersion induced fading.

Abstract: An optical data transmitter is described that includes a precoder that converts an input data signal to a binary precoded data signal and to a complementary binary precoded data signal. A delay element delays one of the complementary binary precoded data signal and the binary precoded data signal relative to the other by a time corresponding to less than one bit period of the binary precoded data signal. A differential amplifier converts the binary precoded data signal and the complementary binary precoded data signal to a four-level data signal and to a complementary four-level data signal. An optical data modulator modulates an amplitude of an optical signal applied to an optical input of the optical data modulator in response to at least one of the four-level data signal and the complementary four-level data signal to generate a modulated optical output signal.

Abstract: A suite of optical performance monitoring (OPM) methods, based on optical subcarrier multiplexing, are described by the invention. The strength of this approach lies in the simplicity of double sideband subcarrier signals and the fact that these signals travel the complete optical path with the baseband signal of interest. The subcarrier signals can be recovered using techniques described in the application and are immune to fiber dispersion induced fading.

Abstract: The present invention is a wide field of view electro-optic detector and locator of coherent light of unknown wavelength that includes a collecting optic that collimates incoming optical radiation, a common-path electro-optic polarization interferometer placed at an exit pupil plane, an imaging optic, a detector array placed one focal length away from said imaging optic, an image processor that processes the incoming signal in a manner that is independent of the phase of the modulation signal, and an output device. The preferred collecting optic includes a first lens, a field lens, and a collimating lens. The preferred interferometer includes a first polarizer, a liquid crystal variable phase modulator, a fixed phase retarder, and a second polarizer.