Abstract: A multiwavelength switch is provided. The switch includes at least one optical input for receiving an optical beam and at least two optical outputs. A dispersion element receives the optical beam from the optical input and spatially separates the optical beam into a plurality of wavelength components. A collimating element is provided for collimating the plurality of wavelength components. An actuatable optical arrangement receives the collimated plurality of wavelength components from the collimating element. The actuatable optical arrangement includes a digital micromirror device (DMD) from which at least one wavelength component is reflected at least twice before being directed to a selected one of optical outputs.

Abstract: A programmable encoder is provided that includes at least one optical input for receiving a modulated broadband optical signal and at least one optical output. A dispersion element receives the optical signal from the optical input and spatially separates the optical signal into a plurality of wavelength components. A collimating element is provided for collimating the plurality of wavelength components. An actuatable optical arrangement receives the collimated plurality of wavelength components from the collimating element. The actuatable optical arrangement includes a digital micromirror device (DMD) from which a programmably selected subset of wavelength components are reflected at least twice before being directed to a selected one of optical outputs to thereby encode the CDMA signal.

Abstract: An all-optical, optical cross-connect includes first and second pluralities of multiport optical devices. Each of the first plurality of multiport optical devices have at least one input port for receiving a WDM optical signal and a plurality of output ports for selectively receiving one of more wavelength components of the optical signal. Each of the second plurality of multiport optical devices have a plurality of input ports for selectively receiving one of more wavelength components of the optical signal and at least one output port for selectively receiving one of more wavelength components of the optical signal. At least one of the first or second plurality of multiport optical devices are all-optical switches that can route every wavelength component independently of every other wavelength component.

Abstract: An optical spectral detection device utilizing free space optical beam propagation is provided. The device includes at least one optical fiber input, at least one opto-electronic detection device, an optical element having an actuator with at least one tilt axis, and a diffraction element having a surface thereon. The device also includes an optical beam transfer arrangement positioned between the optical element and the diffraction element such that tilt actuation of the optical element elicits a proportional change in an angle of incidence of the optical beam onto the diffraction element, wherein the center of rotation for the angular change is the surface of the diffraction element. The spectral properties of the optical beam that are detected are selected by selectively positioning the optical element about at least one of the tilt axes.

Abstract: An all-optical, optical cross-connect includes first and second pluralities of multiport optical devices. Each of the first plurality of multiport optical devices have at least one input port for receiving a WDM optical signal and a plurality of output ports for selectively receiving one of more wavelength components of the optical signal. Each of the second plurality of multiport optical devices have a plurality of input ports for selectively receiving one of more wavelength components of the optical signal and at least one output port for selectively receiving one of more wavelength components of the optical signal. At least one of the first or second plurality of multiport optical devices are all-optical switches that can route every wavelength component independently of every other wavelength component.

Abstract: An optical wavelength routing device utilizes a free space optical beam propagating therethrough is provided. The device includes at least one optical fiber input, at least one optical fiber output, an optical element having an actuator with at least one tilt axis and a diffraction element having a surface thereon. The device also includes an optical beam-splitting element having spatially varying optical properties. An optical beam transfer arrangement is positioned between the optical element and the diffraction element such that tilt actuation of the optical element elicits a proportional change in an angle of incidence of the optical beam onto the diffraction element, wherein the center of rotation for the angular change is the surface of the diffraction element. Optical routing between the fiber input and the fiber output can be configured by the positioning of the optical element.

Abstract: A WDM optical transmission system is provided that operates at a plurality of channel wavelengths. The system includes at least three nodes at which any one or more of the channel wavelengths can be added or dropped. At least three optical transmission links interconnect the nodes. Each link includes a single waveguide over which travel oppositely-directed WDM signals having channel wavelengths that are interleaved with one another in a pairwise manner. A majority of the optical transmission links each have an optical span loss that corresponds to a level of coherent crosstalk between a reflected channel at a given wavelength co-propagating with a channel at the given wavelength prior to isolating one of the adjacent channels in a node that is less than a level of coherent crosstalk that would otherwise arise if a unidirectional transmission format were employed over a single waveguide in the same system.

Abstract: Polarization monitoring and control in a lightwave communication system is achieved by using an in-line polarimeter in conjunction with a polarization controller. The devices are readily compact, accurate and therefore capable of implementation in a variety of system applications. In one embodiment, a polarimeter and controller can be coupled together by a feedback loop between the polarimeter output and the controller input to provide “active polarization control” (APC).

Abstract: A compensation arrangement for addressing the problem of first-order and second-order polarization mode dispersion (PMD) in an optical fiber communication system includes separate, independent elements for each type of PMD. First-order PMD may be compensated using conventional techniques related to adjusting the transit time differential between the polarization states. The second-order polarization mode dispersion is compensated by recognizing the separate sources of second-order PMD (pulse broadening analogous to chromatic dispersion, additional pulse broadening due to optical filtering (narrowing), and coupling of a portion of the optical signal into the orthogonal polarization relative to the main pulse with a different transmit time. A chirped fiber grating with a variable temperature gradient, a complementary optical filter with variable spectral transmission and a polarizer, respectively, can be used to compensate for these three sources of second-order PMD.

Abstract: An optical switch includes at least one input port for receiving a WDM optical signal having a plurality of wavelength components, at least three output ports, and a plurality of wavelength selective elements each selecting one of the wavelength components from among the plurality of wavelength components. A plurality of optical elements are also provided, each of which are associated with one of the wavelength selective elements. Each of the optical elements direct the selected wavelength component that is selected by its associated selected element to a given one of the output ports independently of every other wavelength component. The given output port is variably selectable from among all the output ports.

Abstract: An all-optical, optical cross-connect includes first and second pluralities of multiport optical devices. Each of the first plurality of multiport optical devices have at least one input port for receiving a WDM optical signal and a plurality of output ports for selectively receiving one of more wavelength components of the optical signal. Each of the second plurality of multiport optical devices have a plurality of input ports for selectively receiving one of more wavelength components of the optical signal and at least one output port for selectively receiving one of more wavelength components of the optical signal. At least one of the first or second plurality of multiport optical devices are all-optical switches that can route every wavelength component independently of every other wavelength component.

Abstract: In accordance with the invention, an optical fiber Bragg grating comprises a length of gloss optical fiber having a core, a Bragg grating formed along the core, a glass cladding and a polymer coating on the cladding having an index of refraction matched to that the cladding. Such index matching can reduce the cladding mode loss by a factor of four over current levels. A preferred coating material comprises fluorinated urethane acrylate.

Abstract: A novel superfluorescent fiber source (SFS) has high power and broad bandwidth, and can advantageously be used in a variety of applications, e.g., optical coherent tomography systems, sliced spectrum optical fiber communication systems, and optical position sensing systems. The novel SFS comprises a first and a second length of rare earth-doped optical fiber, with an optical isolator therebetween. Light from a first pump source is provided to the first length of optical fiber, and light from a second pump source is provided to the second length of optical fiber. An optional reflector is disposed to reflect at least some upstream-propagating light back into the first length of optical fiber, whereby generation of long-wavelength amplified spontaneous emission (ASE) is facilitated. The long-wavelength ASE is transmitted through the optical isolator to the second length of rare earth-doped optical fiber, where broadband ASE is generated and the long-wavelength ASE is amplified.

Abstract: An optical switch includes at least one input port for receiving a plurality of channel wavelengths of an optical signal and a plurality of output ports. A plurality of wavelength selective elements are also provided, which each select a channel wavelength from among the plurality of channel wavelengths received at the input port. A plurality of optical elements are respectively associated with the plurality of wavelength selective elements. Each of the optical elements direct one of the selected channel wavelengths, which are selected by the associated wavelength selective element, to any one of the output ports independently of all other channel wavelengths and with a selectively variable degree of attenuation. The switch also includes a controller for adjusting a configuration of the optical elements to provide the channel wavelengths with the selectively variable degree of attenuation.

Abstract: In a WDM optical communication system that includes a plurality of nodes interconnected by communication links, a node is provided that includes a first plurality of transponders each generating and/or receiving an information-bearing optical signal at a different channel wavelength from one another. An optical coupling arrangement, which may include one or more reconfigurable optical switches, transfers the channel wavelengths between a link connected to the node and the first plurality of transponders. The arrangement is adaptable to reconfigure its operational state to selectively direct different ones of the channel wavelengths from the link to different ones of the transponders without disturbing the optical path through the node traversed by any other channel wavelengths. A communications and configuration arrangement is provided, which transfers data identifying the respective channel wavelengths at which the transponders operate from the transponders to the optical coupling arrangement.

Abstract: In a WDM optical communication system that includes a plurality of nodes interconnected by communication links, a node is provided that includes a reconfigurable optical switch having a plurality of input ports and at least one output port. The node also includes a plurality of transmitters that are each coupled to one of the input ports of the optical switch. Each of the transmitters generate an information-bearing optical signal at a different channel wavelength from one another. The reconfigurable optical switch is adaptable to receive at any of the input ports any of the channel wavelengths at which the plurality of transmitters operate and direct the channel wavelengths to the output port. At least one backup transmitter is coupled to one of the input ports of the optical switch. The backup transmitter includes a tunable laser tunable to any of the channel wavelengths at which the plurality of transmitters operate.

Abstract: An all-optical, optical cross-connect includes first and second pluralities of multiport optical devices. Each of the first plurality of multiport optical devices have at least one input port for receiving a WDM optical signal and a plurality of output ports for selectively receiving one of more wavelength components of the optical signal. Each of the second plurality of multiport optical devices have a plurality of input ports for selectively receiving one of more wavelength components of the optical signal and at least one output port for selectively receiving one of more wavelength components of the optical signal. At least one of the first or second plurality of multiport optical devices are all-optical switches that can route every wavelength component independently of every other wavelength component.

Abstract: In a WDM optical communication system that includes a plurality of nodes interconnected by communication links, a node is provided which includes an optical coupling arrangement having at least one input port for receiving a WDM signal and a plurality of output ports for selectively receiving one or more wavelength components of the WDM optical signal. The optical coupling arrangement is adaptable to reconfigure its operational state to (i) selectively direct any one of the wavelength components received on the input port to any of the output ports independently of any other of the wavelength components and (ii) selectively direct any combination of two or more of the wavelength components from the input port to at least two of the output ports that serve as WDM output ports. At least one optical WDM interface is optically coupled to a first of the WDM output ports.

Abstract: A refractive index grating according to this invention is a tilted grating in a single mode optical waveguide, with a photosensitivity profile that includes at least one “tuning region” in the waveguide core. Appropriate choice of the photosensitivity profile of the waveguide can result in a “supernull” in the LP01,f to LP01,b coupling. That is to say, the angular range of the tilt angle &thgr; over which the core mode coupling is essentially zero (i.e., <−30 dB) can be substantially increased, to more than 0.1°, or even 0.2 or 0.5°, as compared to the angular range obtainable without a “tuning region” in the waveguide core. The increased angular range provides for improved manufacturability of the grating. In preferred embodiments the grating has a large cladding loss (>20 dB) and bandwidth (>20 nm). A method of trimming a grating is also disclosed.

Abstract: Disclosed is an article that comprises an optical waveguide mode converter for converting light of wavelength &lgr; in a few-moded optical waveguide from a given guided mode (e.g., LP01,f) to another guided mode (e.g., LP02,b). The converter comprises a tilted refractive index grating in the core of the waveguide. Appropriate choice of the refractive index profile n(r), photosensitivity p(r) and tilt angle &thgr; makes possible substantial nulling of the coupling between some guided modes (e.g., LP01,f to LP01,b and LP01,f to LP11,b), and substantial maximization of the coupling between other guided modes (e.g., LP01,f to LP02,b). Mode converters according to the invention can be advantageously used in optical fiber communication systems in add/drop multiplexers.