Abstract: A multi-stage lasing semiconductor optical amplifier (SOA) device amplifies an optical signal. The multi-stage SOA includes at least two SOA stages coupled in series. Each SOA stage includes a semiconductor gain medium and a laser cavity including the semiconductor gain medium. The medium is pumped above a lasing threshold for the laser cavity, which clamps the gain of the medium. An optical signal propagating through the medium is amplified by the gain-clamped medium. The SOA stages are characterized by a design parameter which varies from stage to stage. In a preferred embodiment, the design parameter includes a noise figure and a saturable power, with both parameters increasing as the optical signal propagates from stage to stage. As a result, the multi-stage SOA can achieve better noise performance and higher power outputs compared to comparable SOAs of constant noise figure and saturable power.

Abstract: A package having one or more integrated circuit photonic devices in a hermetically sealed enclosure. The photonic devices may be sources or detectors of light. The sealed enclosure consists of a transparent window attached to a first level housing. The transparent window contains patterned electrically conductive traces for purposes of routing electrical signals to and from semiconductor chip, which is bonded to patterned window. A second level housing is attached to the first level housing, and aligned via mechanical features incorporated with the transparent window. The second level housing provides a receptacle for a plug having light waveguides or optical fibers that are aligned with the photonic devices when inserted into the receptacle. One or more pins are inserted through the plug and the second level housing to secure the plug in the receptacle to the hermetically sealed photonic devices, such as VCSEL's on an integrated circuit semiconductor.

Abstract: An N×N optical switching array device and system are disclosed. In one aspect, an optical switching device for communicating optical signals is provided. The device includes a plurality of optical inputs operable to communicate optical signals, a plurality of optical outputs optically coupled to the optical inputs and at least one thermo-optic array optically coupled to the plurality of optical inputs and the plurality of optical outputs. The device further includes an thermo-optical array operable to deflect an optical signal from one of the plurality of optical inputs to one of the plurality of optical outputs in response to a temperature differential.

Abstract: An optical device according to the present invention is disclosed which comprises a first optical fiber and a second optical fiber disposed adjacent to each other, the first fiber being optically configured to receive incident light; a polarization dependent reflector having a preferred axis; a common lens configured to optically couple the first and second fibers to the polarization dependent reflector; and a third optical fiber coupled to the polarization dependent reflector through a second lens. The device may be characterized in that the optical device is aligned such that incident light launched into the polarization dependent reflector is provided to the second fiber at both a predetermined angle and a predetermined polarization; and such that incident light launched into the polarization dependent reflector is launched into the third fiber at a predetermined polarization.

Abstract: A method and apparatus for multiplexing/de-multiplexing optical signals, comprising of a linear polarizer (450, fig. 4c), wave plates (452, fig. 4c), and a beam displacer/combiner (454, fig. 4c), wherein the wave plates (340, 342, 344, 346, fig. 4c) optically coupled to the linear polarizer (400, 402, 404, AB, fig. 4c), and the wave plates rotate both odd and even channel components of an optical beam between a linear and an orthogonal relationship depending on the propagation direction, and each of wave plate is of a selected length and index of refraction which together determine a free spectral range which corrresponds to a spacing between adjacent gridlines of a selected wavelength grid, and each of the wave plates is tuned to even symmetry with the selected wavelength grid and wherein the beam displacer/combiner (420, AB, 422 AB, 426, 428, FIG. 4c) displaces and combines orthogonally polarized odd and even channel components of an optical beam depending on a propagation direction.

Abstract: A data modifier including a trigger subsystem (140a) and a modification subsystem (160a). The trigger subsystem generates a trigger signal when it detects the presence of a user predefined pattern in an input data stream (112). The modification subsystem responds to the trigger signal by altering user specified portions of a first input datum of the input data stream to create a corresponding output datum (114) having a fixed, real-time delay with respect to the first input datum.

Abstract: In a semiconductor p-i-n photodiode an undoped absorption region (10) is epitaxially grown between two highly doped regions (14, 16). In prior art lattice matched InGaAs p-i-n photodiodes current epitaxial structures use low InP cap (16) doping (n∩2.5-6x1016/cm3), and nominally undoped (not intentionally doped, n∩1x10?13-5x1014/cm3?) InGaAs absorption regions (10). The shunt resistances of p-i-n photodiodes according to the present invention with intentional doping between n∩5x1017/cm3 and 1x1014/cm3, in the InGaAs absorption region (52, 60) are significantly increased over that of a standard structure (non-intentionally doped).

Abstract: Various aspects of thermal compensated Bragg grating filters are disclosed. In one disclosed aspect, an optical fiber having a Bragg grating therein is laid adjacent to a torsion member, and the two are then rigidly affixed between a torsion adjusting member and a compensating member. The torsion adjusting member may then be rotated, twisting the optical fiber around the torsion member, and thus applying torsion to the optical fiber containing the Bragg grating, and changing the period of the Bragg grating. A further disclosed aspect provides an optical fiber, containing a Bragg grating filter therein, which is rigidly affixed between a torsion adjusting member and a compensating member in an axis other than the compensating member's longitudinal axis. The torsion adjusting member may then be rotated to apply torsion to the optical fiber, and change the period of the Bragg grating. Another disclosed aspect comprises an optical fiber, containing a Bragg grating filter therein, and a compensating member having a desired thermal coefficient of expansion. The optical fiber is bent through a curve and affixed to the compensating member such that torsion is applied to the Bragg grating region of the optical fiber.

Abstract: In a semiconductor p-i-n photodiode an undoped absorption region (10) is epitaxially grown between two highly doped regions (14, 16) In prior art lattice matched InGaAs p-i-n photodiodes current epitaxial structures use low InP cap (16) doping (n˜25−6×1016/cm3), and nominally undoped (not intentionally doped, n˜1×1013−5×1014/cm3) InGaAs absorption regions (10) The shunt resistances of p-i-n photodiodes according to the present invention with intentional doping between n˜5×1017/cm3 and 1×1014/cm3, in the InGaAs absorption region (52, 60) are significantly increased over that of a standard structure (non-intentionally doped)

Abstract: A method and apparatus for compensating an optical filter is disclosed The device substantially maintains the selected center wavelength in the optical filter across a range of operating temperatures In an embodiment of the invention an optical filter is disclosed for filtering a selected channel among a plurality of multiplexed channels of an optical communication The optical filter includes an optical fiber and an elongate housing The optical fiber has a first side and a second side and a filter portion intermediate the first side and the second side, and the optical fiber for transmitting the multiplexed optical communication and the filter portion for filtering the selected channel The elongate housing includes exposed end portions through which the optical fiber extends The optical fiber is affixed at each exposed end portion The exposed end portions exhibit between them a negative coefficient of thermal expansion sufficient to generate strains on the filter to substantially stabilize a filtered wavelength to substantially correspond with the selected channel during temperature variations In an alternate embodiment of the invention the elongate housing is defined about a longitudinal axis and including a first anchor pad and a second anchor pad to which the filter portion is affixed At least one of the anchor pads is at least initially movable in a plane intersecting the longitudinal axis to vary a strain on the filter portion to tune a center wavelength of the selected channel In another embodiment of the invention an optical filter for filtering an optical signal is disclosed In still another embodiment of the invention a method for compensating an optical filter is disclosed

Abstract: A monolithic semiconductor device extends primarily along a vertical direction and includes the following layers. A first semiconductor layer and a second semiconductor layer form an active region between them. A third semiconductor layer is doped the same type as the second semiconductor layer but is lattice mismatched to the second semiconductor layer. The lattice mismatch results in unwanted electrical effects. An additional doping layer, preferably a delta doping layer, is located in close proximity to the interface between the second and third semiconductor layers. The delta doping layer mitigates the unwanted electrical effects introduced by the lattice mismatch. In a preferred embodiment, the device further includes a bottom mirror layer and a top mirror layer, which together form a laser cavity including the active region.

Abstract: A method, systems and apparatus for providing true-time-delayed signals using optical inputs is disclosed. In one aspect a system for providing optical true-time-delayed signals is provided. The system includes at least one optical source having emitting an optical signal having a predetermined wavelength, an optical waveguide optically coupled to the at least one optical source, and a diffraction element optically coupled to the waveguide, the diffraction element positioned along the waveguide at a predetermined distance.

Abstract: A laser apparatus (100), which generates laser light to be transmitted through an optical transmission system includes a laser (52) that emits light that is substantially linearly polarized, a housing (54) in which the laser is mounted, and a quarter wave retarder plate (102). The quarter wave retarder plate is disposed so that the emitted laser light passes through it prior to transmission of the emitted laser light through the optical transmission system. The quarter wave retarder plate causing the emitted light to become circularly polarized with a predefined handedness. The quarter wave retarder plate is also disposed so that light reflected back toward the laser passes through the quarter wave retarder plate a second time prior to reaching the laser, causing the reflected light to become linearly polarized with a linear polarization that is orthogonal to the polarization state of the light emitted by the laser.

Abstract: A method and apparatus for multiplexing/de-multiplexing optical signals is disclosed. The method and apparatus are applicable to a range of optical multiplexing techniques including, but not limited to: wavelength division multiplexing (WDM), dense wavelength division multiplexing (DWDM) and frequency division multiple accessing (FDMA). The disclosed devices do not require active components. The disclosed devices may be implemented with fiber or fiberless optical communication systems including telecommunications systems. The devices may be used on their own or as part of a larger system such as a multi-stage mux/demux, an optical switch, or router. Additionally, the devices are passively thermally stabilized with the result that their tuning is substantially invariant across a wide temperature range. The optical device includes a linear polarizer, at least one wave plate and a beam displacer/combiner. The wave plate optically couples to the linear polarizer and rotates both odd and even channel components of an optical beam between a linear and an orthogonal relationship depending on the propagation direction. The wave plate includes a primary and a compensating birefringent element with respective first and second lengths and first and second indices of refraction. The first and second lengths and the first and second indices of refraction together determinative both of a free spectral range for the at least one wave plate corresponding to a spacing between adjacent gridlines of the selected wavelength grid, and of a combined optical pathlength difference for the wave plate substantially invariant with temperature.

Abstract: A method and apparatus for the parallel optical processing of a plurality of optical beams within a single optical processing unit is provided. The optical processing unit may perform any of the functions associated with the following 3 port devices: a circulator, a demultiplexer, an interleaver, a multiplexer, a forward power tap, a reverse power tap, a power splitter, a polarization beam combiner and a polarization beam splitter. Access to the optical processing unit is provided by opposing bundles of optical fibers the input and output of which is directed from and to the optical function unit by lenses. Each triplet of optical fibers provides 3 ports of access to the optical processing unit. This allows multiple discrete optical beams each with unique optical parameters, e.g. wavelength, power, modulation, polarization, propagation direction, etc. to be individually delivered, to the optical processing unit on respective optical fibers, to be processed in parallel within the optical processing unit, and to be output individually on the appropriate ones of the optical fibers associated with each of the triplets. The performance of a given optical processing unit with respect to any optical beam delivered to it may be improved by coupling the appropriate ports of two or more of the triplets to effectively reintroduce to the optical processing unit via the appropriate port(s) of a second of the triplets at least a portion of a beam initially introduced to the optical processing unit through a selected port(s) of a first of the triplets.

Abstract: A portion of an optical device is disclosed. In one aspect of the present invention, the device comprises a cylinder formed about an axis having first and second ends, the second end being formed so as to define a segment of an inward-facing concave spherical surface. A module is provided defining a cylinder formed about the axis and having first and second ends and an optical element disposed therein about the axis. The first end of the module is formed so as to define a segment of an outward-facing convex spherical surface, and the convex surface is complimentary in shape to the concave surface. The complimentary concave and convex surfaces of the cylinder and the module are mated so as to allow the optical element to be aligned about a plane forming a predetermined angle with the axis.

Abstract: Thermally compensated wavelength division demultiplexers and multiplexers are disclosed. In one aspect, thermally compensated optical systems for use in an optical network are disclosed. The systems include a diffraction grating coupled to a grating mount having a temperature coefficient. The systems further include an optical fiber coupled to a fiber mount having a temperature coefficient and a lens assembly coupled to a lens mount. The lens mount is operable to position the lens assembly between the fiber mount and the grating mount and includes a substantially similar temperature coefficient to the fiber mount.

Abstract: A miniature dense wavelength division multiplexer (DWDM) is disclosed. A plurality of multi-window wavelength multiplexers (MWDM) are cascaded and optically coupled to form a tree, and each of the MWMDMs forming the tree comprises a microbend coupler. The forming of the MWDM tree is characterized by the absence of the bending of optical fibers external to the microbend couplers. A finished DWDM assembly measures less than 50 mm in width.

Abstract: The fiber optic devices disclosed include fiber optic coupler-isolator combinations. These combinations are especially applicable to fiber optic tapping and pumping arrangements. By integrating such devices into a housed subassembly, enhanced size and design characteristics are achieved. The first coupler (324) may be used for multiplexing a signal and a pump beam whereas the second (354) is used for monitoring. The isolator (318) receives and transmits the light to the couplers via slanted GRIN lenses.

Abstract: The invention relates to an attenuation device for attenuating electromagnetic radiation that is emitted by a board and an electric plug (6) inserted in a female plug (4), provided for the electric connection of a transceiver to a data processing device. The inventive device comprises a plug section (2) with which the attenuation device (1) is plugged into the female plug (4). Said plug section (2) consists of an attenuation material that absorbs the electromagnetic radiation emitted by the plug (6). The device is further provided with a gripping section (3) with which the attenuation device (1) can be manually actuated.