Abstract: A plasmon-based optical modulator comprises a substrate, a layer of high reflectivity material disposed over the substrate, a relatively thin dielectric layer disposed over a top major surface of the layer of high reflectivity material and a plurality of graphene strips disposed in parallel across a top major surface of the relatively thin dielectric layer, each graphene strip exhibiting a predetermined width w, with adjacent strips separated by a predetermined spacing s. A first electrical contact is coupled to the plurality of graphene strips and a second electrical contact is coupled to the layer of high reflectivity material, where the values of w, s, and voltage applied between the first and second electrical contacts determines a resonant wavelength of the plasmon-based optical modulator, with changes in the applied voltage changing between absorption and non-absorption of an applied optical input signal.

Abstract: A two-dimensional (2D) optical fiber array component takes the form of a (relatively inexpensive) fiber guide block that is mated with a precision output element. The guide block and output element are both formed to include a 2D array of through-holes that exhibit a predetermined pitch. The holes formed in the guide block are relatively larger than those in precision output element. A loading tool is used to hold a 1×N array of fibers in a fixed position that exhibits the desired pitch. The loaded tool (holding the pre-aligned 1×N array of fibers) is then inserted through the aligned combination of the guide block and output element, and the fiber array is bonded to the guide block. The tool is then removed, re-loaded, and the process continued until all of the 1×N fiber arrays are in place. By virtue of using a precision tool to load the fibers, the guide block does not have to be formed to exhibit precise through-hole dimensions, allowing for a relatively inexpensive guide block to be used.

Abstract: A compact, wavelength-stabilized laser source is provided by utilizing a specialty gain element (i.e., formed to include a curved waveguide topology), where a separate wavelength stabilization component (for example, a fiber Bragg grating (FBG)) is used one of the mirrors for the laser cavity. That is, the FBG takes the place of the physical “front facet” of the gain element, and functions to define the laser cavity in the first instance, while also utilizing the grating structure to impart the desired wavelength stability to the output from the packaged laser source. As a result, the FBG is disposed within the same package used to house the gain element and provides a wavelength-stabilized laser source in a compact form.

Abstract: A composite substrate includes a submount substrate of an alternating pattern of electrically insulative portions, pieces, layers or segments and electrically conductive portions, pieces, layers or segments, and a shaft, back or plate for supporting the alternating pattern of electrically insulative portions and electrically conductive portions. An active device having a P-N junction can be mounted on the submount substrate. The electrically insulative portions, pieces, layers or segments can be formed from diamond while the electrically conductive portions, pieces, layers or segments can be formed from a metal or metal alloy.

Abstract: A fiber-based optical amplifier is assembled in a compact configuration by utilizing a flexible substrate to support the amplifying fiber as flat coils that are “spun” onto the substrate. The supporting structure for the amplifying fiber is configured to define the minimal acceptable bend radius for the fiber, as well as the maximum diameter that fits within the overall dimensions of the amplifier package. A pressure-sensitive adhesive coating is applied to the flexible substrate to hold the fiber in place. By using a flexible material with an acceptable insulative quality (such as a polyimide), further compactness in the final assembly is achieved by locating the electronics in a space underneath the fiber enclosure.

Abstract: An optical amplifier module is configured as a multi-stage free-space optics arrangement, including at least an input stage and an output stage. The actual amplification is provided by a separate fiber-based component coupled to the module. A propagating optical input signal and pump light are provided to the input stage, with the amplified optical signal exiting the output stage. The necessary operations performed on the signal within each stage are provided by directing free-space beams through discrete optical components. The utilization of discrete optical components and free-space beams significantly reduces the number of fiber splices and other types of coupling connections required in prior art amplifier modules, allowing for an automated process to create a “pluggable” optical amplifier module of small form factor proportions.

Abstract: An OTDR system utilizes a laser source that is turned “on” and kept powered until its light reaches the end of the fiber span being measured (i.e., until the fiber span is fully illuminated). At any point in time after the fiber is fully illuminated, the laser source can be turned “off”. The return (reflected and backscattered) signal is directed into a photodetector of the OTDR, and is measured from the point in time when the fiber span starts to be illuminated. The measurements are made by sampling the return signal at predetermined time intervals—defined as the sampling rate. The created power samples are then subjected to post-processing in the form of a differentiation operation to create a conventional OTDR trace from the collected data.

Abstract: An OTDR system utilizes a laser source that is turned “on” and kept powered until its light reaches the end of the fiber span being measured (i.e., until the fiber span is fully illuminated). At any point in time after the fiber is fully illuminated, the laser source can be turned “off”. The return (reflected and backscattered) signal is directed into a photodetector of the OTDR, and is measured from the point in time when the fiber span starts to be illuminated. The measurements are made by sampling the return signal at predetermined time intervals—defined as the sampling rate. The created power samples are then subjected to post-processing in the form of a differentiation operation to create a conventional OTDR trace from the collected data.

Abstract: A two-dimensional (2D) optical fiber array component takes the form of a (relatively inexpensive) fiber guide block that is mated with a precision output element. The guide block and output element are both formed to include a 2D array of through-holes that exhibit a predetermined pitch. The holes formed in the guide block are relatively larger than those in precision output element. A loading tool is used to hold a 1×N array of fibers in a fixed position that exhibits the desired pitch. The loaded tool (holding the pre-aligned 1×N array of fibers) is then inserted through the aligned combination of the guide block and output element, and the fiber array is bonded to the guide block. The tool is then removed, re-loaded, and the process continued until all of the 1×N fiber arrays are in place. By virtue of using a precision tool to load the fibers, the guide block does not have to be formed to exhibit precise through-hole dimensions, allowing for a relatively inexpensive guide block to be used.

Abstract: A fiber-based optical amplifier is assembled in a compact configuration by utilizing a flexible substrate to support the amplifying fiber as flat coils that are “spun” onto the substrate. The supporting structure for the amplifying fiber is configured to define the minimal acceptable bend radius for the fiber, as well as the maximum diameter that fits within the overall dimensions of the amplifier package. A pressure-sensitive adhesive coating is applied to the flexible substrate to hold the fiber in place. By using a flexible material with an acceptable insulative quality (such as a polyimide), further compactness in the final assembly is achieved by locating the electronics in a space underneath the fiber enclosure.

Abstract: A multiport optical switch is used to controllably select a specific incoming optical signal that is to be processed by an associated optical channel monitor (OCM). The OCM includes a tunable optical filter and photodetector arrangement, and is configured to measure the optical spectrum of the incoming optical signal and extract information associated with the various optical channels forming the incoming optical signal (i.e., power, wavelength, OSNR, etc., per channel in the signal). The OCM also includes a processor that generates a pair of output control signals, a first signal to control the wavelength scanning process of the tunable optical filter and a second signal to control the setting of the multiport optical switch. The second signal may also be used to perform “detuning” of a selected input of the multiport optical switch, providing the ability to adjust the power level of an input signal prior to entering the OCM.

Abstract: A series combination of a shortwave pass (SWP) filter and a longwave pass (LWP) filter is provided in an arrangement where the filters are separately and independently controlled by voltages applied to the respective filters. The applied voltages modify the response profile of the associated filters, where changes in the voltage applied to the SWP filter changes its cut-off wavelength ?S and changes in the voltage applied to the LWP filter changes its cut-on wavelength ?L (the bandwidth of the combined arrangement between the span between ?L and ?S). The ability to independently tune both the SWP and LWP filters allows for the combined result of their series combination to modify both the center wavelength (CWL) and bandwidth (BW) of the overall filter resulting from their combination.

Abstract: A multiport optical switch (such as an N×1 switch) is used to controllably select a specific incoming optical signal that is to be processed by an associated optical channel monitor (OCM). The OCM includes a tunable optical filter and photodetector arrangement, and is configured to measure the optical spectrum of the incoming optical signal and extract information associated with the various optical channels (wavelengths) forming the incoming optical signal (i.e., power, wavelength, OSNR and the like for each channel). The OCM also includes a signal processing component that generates a pair of output control signals, a first signal to control the wavelength scanning process of the tunable optical filter and a second signal to control the setting of the multiport optical switch.

Abstract: An optical amplifier assembly for determining a parameter of an optical fiber configured to amplify an optical signal being propagated therethrough, the assembly comprising: at least one amplifier pump light source assembly configured to transmit light at a plurality of wavelengths into the optical fiber; a receiver configured to receive light that has propagated through at least part of the optical fiber; and a processor configured to determine the parameter of the optical fiber based on the received light.

Abstract: A micro splice protector for a fusion connection between a pair of optical fibers takes the form of a cylindrical sleeve of dimensions similar to that of the fusion splice itself, with an epoxy material used to encase the fusion splice within the sleeve. The sleeve is formed to exhibit an inner diameter only slightly greater than the outer diameter of the optical fibers, with the length of the sleeve typically formed to be only slightly longer than the stripped end terminations of the pair of fibers being spliced together. The cylindrical sleeve is formed of a rigid, but lightweight, material (e.g., stainless steel, fused silica) and an epoxy material is injected into the configuration to fill any gaps between the fusion connection and the inner surface of the sleeve. The result is relatively stiff fusion splice protector that is extremely small in size and well-suited for use in optical component packages where space is at a minimum.

Abstract: In a method for growing bulk SiC single crystals using chemical vapor transport, wherein silicon acts as a chemical transport agent for carbon, a growth crucible is charged with a solid carbon source material and a SiC single crystal seed disposed therein in spaced relationship. A halosilane gas, such as SiCl4 and a reducing gas, such as H2, are introduced into the crucible via separate inlets and mix in the crucible interior. The crucible is heated in a manner that encourages chemical reaction between the halosilane gas and the reducing gas leading to the chemical reduction of the halosilane gas to elemental silicon (Si) vapor. The produced Si vapor is transported to the solid carbon source material where it reacts with the solid carbon source material yielding volatile Si-bearing and C-bearing molecules.

Abstract: An electro-optic modulator for high voltage applications exhibits reduced corona and arcing by utilizing dielectric-coated electrodes in conjunction with a non-centrosymmetric crystal. The inclusion of an insulative coating (i.e., a dielectric material) on at least a portion of the electrodes reduces the possibility of arcing or corona, without requiring the application of any type of coating material directly on the crystal itself. Thus, the birefringent response of the crystal is not impacted by this coated electrode configuration of the present invention. In one configuration, the exposed surfaces of the electrodes are coated with an insulative material, while maintaining a direct contact between the electrodes and the surface of the crystal.

Abstract: A multiport optical switch (such as an N×1 switch) is used to controllably select a specific incoming optical signal that is to be processed by an associated optical channel monitor (OCM). The OCM includes a tunable optical filter and photodetector arrangement, and is configured to measure the optical spectrum of the incoming optical signal and extract information associated with the various optical channels (wavelengths) forming the incoming optical signal (i.e., power, wavelength, OSNR and the like for each channel). The OCM also includes a signal processing component that generates a pair of output control signals, a first signal to control the wavelength scanning process of the tunable optical filter and a second signal to control the setting of the multiport optical switch.

Abstract: A housing used for electronic devices includes a structural frame element formed of a metal matrix composite (MMC) for providing improved stiffness over other materials currently in use. The MMC is a metal matrix (formed of a material such as aluminum), with a reinforcing material (such as a glass fiber or ceramic) dispersed within the metal matrix. The composition of the reinforcing material, as well as the ratio of reinforcing material to metal, define the stiffness (resistance to bending) and/or strength (resistance to breaking) achieved, and various compositions may be used for different housings, depending on the use of the electronic device. The element may be configured as a structural frame member, or may be embedded within another material forming the structural frame element. In another embodiment, the MMC may be used to form various components of the complete housing, including the enclosure itself.

Abstract: A method and system of forming large-diameter SiC single crystals suitable for fabricating high crystal quality SiC substrates of 100, 125, 150 and 200 mm in diameter are described. The SiC single crystals are grown by a seeded sublimation technique in the presence of a shallow radial temperature gradient. During SiC sublimation growth, a flux of SiC bearing vapors filtered from carbon particulates is substantially restricted to a central area of the surface of the seed crystal by a separation plate disposed between the seed crystal and a source of the SiC bearing vapors. The separation plate includes a first, substantially vapor-permeable part surrounded by a second, substantially non vapor-permeable part. The grown crystals have a flat or slightly convex growth interface. Large-diameter SiC wafers fabricated from the grown crystals exhibit low lattice curvature and low densities of crystal defects, such as stacking faults, inclusions, micropipes and dislocations.