Abstract:
In accordance with the invention, nanoscale connectors particularly useful for connecting microscale devices comprise free-standing nanoscale conductors. The nanoscale conductors are conveniently fabricated in sets of controlled, preferably equal length by providing a removable substrate, growing conductive nanotubes or nanowires on the substrate, equalizing the length of the nanoscale conductors, and removing the substrate. Preferably the removable substrate is soluble, leaving a collection of free standing nanoscale connectors in suspension or solution.
Abstract:
A solder composition that bonds well to oxides and other surfaces to which solder bonding is conventionally difficult is provided. The solder is particularly useful for reliable bonding and packaging of optical components that often have oxide surfaces. The solder composition exhibits a microstructure containing a solder matrix in which is distributed fine, micron-scale islands of rare-earth-containing intermetallic particles. The existence of the islands makes the rare earth elements better available for bonding, and reduce the extent to which the rare earths are oxidized. Advantageously, the solder contains Au and/or Ag, in which the rare earth elements tend to have some solid solubility. Due to this solubility, the Au and/or Ag tend to provide some additional protection of the rare earths against oxidation, and thereby also provide accelerated dissolution of the rare earth into the molten solder.
Abstract:
The emission properties of aligned nanotube arrays are improved by truncating the ends of the nanotubes. Truncation provides nanotubes having a height within, for example, 30% of the average truncated nanotube height, as well as ends substantially free of end caps. The cap-free ends provide desirable field concentration, and the height uniformity increases the number of participating nanotubes.
Abstract:
In accordance with the invention, an optical switching device comprises a light-reflecting mirror containing a magnetic component coupled to a substrate. One or more programmable magnets are provided for moving the mirror by interacting with the magnetic component. The programmable magnets move the mirrors between or among selected positions and then maintain the mirror position without continuous power. Exemplary cross connects and 2×2 switches are described.
Abstract:
Many potential applications of CVD diamond film require the ability to remove a predetermined quantity of material from a surface of the film. We have discovered that such removal is advantageously accomplished by contacting the surface of the polycrystalline diamond film with a metal selected from Fe, Ni, Mn and Ti (preferably Fe and Mn, most preferably Mn), and maintaining the metal-contacted diamond film at a temperature in the range 600-1100° C. (preferably 800-1000° C.) without relative lateral motion between the film and the metal, for an effective time for removal of the quantity of material, exemplarily less than 100 hours. The metal can be in any appropriate form, e.g., a deposited layer, (including a patterned layer), a foil, or powder. We have also discovered that the local thermal conductivity of CVD diamond films typically increases with distance from the lower surface of an as-grown film. Thus, in applications such as heat spreading it will frequently be advantageous to remove some of the fine-grained, low thermal conductivity material adjacent to the lower surface of the as-grown CVD film. Such removal can be accomplished by means of the above-described technique.
Abstract:
A tunable chromatic dispersion compensator for optical communication systems is disclosed. An optical grating, such as a fiber Bragg grating, non-chirped, linearly chirped or non-linearly chirped, is coated on its outer surface with a coating have a variable diameter and strained is applied to the fiber. The fiber may be latchably strained so that the grating characteristics may be changed or tuned while avoiding use of a continuous power supply. Various optical networking applications using such dispersion compensating devices are also disclosed.
Abstract:
The invention is a reconfigurable optical grating device using force from programmable magnets to alter the mechanical strain, preferably a tensile strain, on the gratings so as to induce a latchable change in grating periodicity using a pulse or short-duration current. It includes apparatus for limiting the maximum strain applied to the grating so that the fiber does not fracture, and it provides strain without rotation or twisting of the fiber grating. In preferred embodiment it provides control of magnetic force so as to accurately obtain a predetermined amount of strain and hence wavelength shift in the grating with a minimal amount of electrical power. The inventive structure is useful, e.g. for wavelength division multiplexed optical communication system comprising wavelength channel add/drop devices and/or dynamically gain-equalized amplifiers.
Abstract:
An actuation device employing square-loop latchable magnetic material having a magnetization direction (polarization) capable of being changed in response to exposure to an external magnetic field is disclosed. The magnetic field is created by a conductor assembly with non-solenoid configuration. Once the magnetization direction of the material is so changed, the external magnetic field is no longer required to maintain the new magnetization direction. The latchable magnetic material is disposed on the mobile electrode of a switching device, and another magnetic material is disposed in spaced relation to the latchable magnetic material on a stationary electrode or surface. By applying an electrical current to a conductor assembly arranged proximate the latchable material, a magnetic field is created about the latchable magnetic material, to change the magnetization direction and thereby enable the attraction or repulsion of another magnetic material located on the stationary electrode. The resulting relative displacement of the mobile and stationary electrodes effects the selective connection or disconnection of electrical contacts carried on or associated with the respective electrodes of the actuation device without requiring additional power in order to maintain the switched state of the electrodes.
Abstract:
A programmable and latchable device for wavelength shifting and chromatic dispersion compensating is disclosed. An optical grating such as a Bragg grating, a nonchirped grating, or a linearly or non-linearly chirped grating, is magnetostrictively strained to alter the dispersion compensator characteristics. In a preferred embodiment, a gradient magnetostrictive body is bonded along its length to the fiber grating. In yet another preferred embodiment, a magnetostrictive body is bonded onto the length of the fiber grating, and a gradient generating, programmable and latchable magnet component is placed adjacent the magnetostrictive body. The body is then latchably strained to a desired level by controlling the extent of magnetization in the magnetostrictive material and the magnet so as to induce or enhance chirping characteristics in the grating. Various optical applications using such are disclosed.
Abstract:
A tunable optical grating device that can be digitally and latchably tuned comprises a length of waveguide including a grating region, and a movable body and fixed substrate attached to the waveguide proximal the grating region. The body is movable from a first position to at least a second position, and in some embodiments to a plurality of positions, along the length of the waveguide to apply a mechanical strain to the grating to shift the wavelength response of the device. The movable body is latchable between the various positions along the length of the waveguide to define a latchably tunable device so that a continuous supply of power is not needed to tune the device. The digitally and latchably tunable optical grating device is useful in WDM communication systems, particularly for adding or dropping channels and for dynamically gain-equalizing optical amplifiers.