Abstract: A metameric optical structure is disclosed having first optical structures comprising diffractive flakes having diffractive structures thereon, and a second optical structures having non-diffractive flakes which may have other special effect properties, such as color shifting. At one angle of incidence or one viewing angle, near normal. The hues match and at other angles they do not match. The diffractive flakes are preferably magnetically aligned so that the grating structures are parallel. Disclosed is also an image formed of at least a first region of diffractive flakes and a second region of non-diffractive flakes wherein the regions are adjacent one another and wherein one of the regions forms a logo, symbol or indicia that appears or disappears in dependence upon the angle of viewing.

Abstract: This invention discloses a magnet for use as a printing plate or printing head that is used for aligning flakes or particles in a paint or ink. A composite sheet or block of magnetizable material is selectively magnetized so that a magnet is formed within the sheet or block that has a shape of a predetermined image, logo, or indica. Dies are used to magnetize the magnetizable material and preferably the does contact the material to be magnetized. A pre-magnetized sheet such as a refrigerator magnet may be re-magnetized differently so that a magnetic image is encoded therein for use as a printing plate. Preferably the printing plate is flexible so that it can be formed to a curved surface of a cylinder or drum for printing. Conveniently these flexible magnets can be changed for other designs and placed on the same drum for use in printing.

Abstract: A financial instrument such as a banknote includes a substrate and a security authenticating device on the substrate, such as a visual or tactile security feature. To allow a holder of the banknote to authenticate the instrument, indicia is provided supported by the substrate for indicating the functionality of the visual or tactile feature. The indicia is reproducible by a photographic process, however the security feature is not reproducible in this manner. The indicia may include a legend at a first location bearing information related to one or more security features. Corresponding security feature location indicators are provided at other locations where the one or more security features are present. This essentially provides symbolic instructions on the banknote as to its security features.

Abstract: A two-step method of making of a security printed image is disclosed and includes coating of the surface of a substrate with a predetermined image shape with an ink containing flaked magnetic pigment in a predetermined concentration, exposing a wet printed image to a magnetic field to align magnetic particles in a predetermined manner, allowing the ink to cure, and coating the substrate with a second printed image on the top of the first image. The second printed image with the same or different image shape is printed with another ink containing clear or dyed ink vehicle mixed with flaked magnetic pigment in a low concentration, exposed to the magnetic field of the same or different configuration as the first printed image and cured until the ink is dry.

Abstract: An image is disclosed comprised of flakes in a carrier, such as an ink vehicle or a paint that can be aligned in a magnetic field. The flakes are aligned so as to produce one or more kinematic features such as a rolling bar that appears to move as the image is tilted. These images can provide security features on high-value documents, such as bank notes.

Abstract: A method for solder bonding a photodiode or an array of photodiodes to a substrate, the photodiode(s) tilted at a predetermined angle, uses a pair solder bumps placed on a photodiode chip opposite a corresponding pair of solder pads placed on the substrate. When the photodiode chip is placed on the substrate, with the solder bumps therebetween, the solder is melted and undergoes a reflow over the surface of the pads. The shape of the pads and the location of the solder bumps on the pads causes the surface tension of the solder to tilt the chip by pulling it to one side.

Abstract: A method for solder bonding a photodiode or an array of photodiodes to a substrate, the photodiode(s) tilted at a predetermined angle, uses a pair solder bumps placed on a photodiode chip opposite a corresponding pair of solder pads placed on the substrate. When the photodiode chip is placed on the substrate, with the solder bumps therebetween, the solder is melted and undergoes a reflow over the surface of the pads. The shape of the pads and the location of the solder bumps on the pads causes the surface tension of the solder to tilt the chip by pulling it to one side.

Abstract: An apparatus and method for determining a suitable location for catheterized delivery or infusion of medication are disclosed. The apparatus includes a probe having a rod coupled to a transducer. The transducer introduces an acoustic or incident wave into the rod. The wave travels through the rod to a tissue in a patient's mouth about the end of the rod, and at least part of the wave is reflected by the tissue back into the rod towards the transducer. The reflected wave contains information relating to the structure of the tissue beneath the probe's tip. The differences between successive oral readings are used to distinguish between different regions of tissue (e.g. containing bone tissue, tooth, ligament, etc.) and/or is used to analyze the density of a particular region, for finding a suitable location for inserting a drill/catheter.

Abstract: A portable dental system and method is disclosed for cleaning endodontic files and the like during a operation such as a root canal procedure. This allows a dentist to clean files in situ while performing the removal of root material. As the file is withdrawn from the patients mouth by the dentist, it can be inserted into a sealed container through the lid and can be cleaned ultrasonically and immediately withdrawn and reinserted into a patients tooth canal for further removal of tooth and root material. Debridement of the files ensures less likelihood the file will break within the canal; furthermore, since no passing off to or cleaning the tip by an assistant is required, there is less likelihood of inadvertent skin puncturing and infection of the dentist or assistant. The sealed disposable container housing a cleaning fluid is insertably removable from the base, which supports it and provides a source of ultrasonic energy thereto.

Abstract: Tuning to maximize the isolation provided by an optical isolator to one of a predetermined plurality of wavelengths is achieved by tilting the isolator with respect to an input beam of light. Further tuning to a peak response for a given wavelength is achieved by rotation of the isolator about its longitudinal axis while or after tilting. In the manufacture of the isolator a test beam is launched into an output port end directed toward the input end. Tilting, or tiling and rotating is initiated and light at the input end is measured while tilting/rotating. When the position is determined where the minimal amount of light is measured, the optical elements are glued or secured in place, thereby providing a way to alter the response of an isolator for a given wavelength of input light.

Abstract: The present invention relates to an in-line optical amplifier that can be coupled to optical fiber, wherein the amplifying medium has a substantially larger mode field than the optical fiber to which it is coupled. The present invention has realized a design to utilize a very high power pump launching a multimoded signal having approximately 1 W of pump power into a block of erbium doped glass having a mode field diameter orders of magnitude larger than the mode field diameter of erbium doped fiber. This invention provides a relatively inexpensive optical amplifier that is compatible for use in an optical fiber telecommunications system or for other uses. Advantageously, this invention provides a device that does not require unwieldy lengths of erbium doped fiber to form an amplifier. By using a block of glass having a rare earth therein, packaging, temperature stabilizing and temperature tuning of the amplifier also become practicable.

Abstract: A device serving as an optical switch or attenuator is disclosed, based on the insertion of a halfwave plate in a collimated beam space between two lenses. All beams have first been aligned to a same polarization state by standard polarization diversity techniques. Moving the halfwave plate into or out of the beam incident thereon enables switching the beams direction based on polarization. Partial insertion of the waveplate attenuates the beam through rotation of polarization state for part of the beam. Preferably, polarizers are used to improve extinction ratio and wavelength flatness.

Abstract: The present invention relates to an in-line optical amplifier that can be coupled to optical fiber, wherein the amplifying medium has a substantially larger mode field than the optical fiber to which it is coupled. The present invention has realized a design to utilize a very high power pump launching a multimoded signal having approximately 1 W of pump power into a block of erbium doped glass having a mode field diameter orders of magnitude larger than the mode field diameter of erbium doped fiber. This invention provides a relatively inexpensive optical amplifier that is compatible for use in an optical fiber telecommunications system or for other uses. Advantageously, this invention provides a device that does not require unwieldy lengths of erbium doped fiber to form an amplifier. By using a block of glass having a rare earth therein, packaging, temperature stabilizing and temperature tuning of the amplifier also become practicable.

Abstract: The invention relates to the design of laser collimators for free space through-the-air optical links. The laser collimator provides means for expanding the diameter of a light beam emitted from the end of a monomode optical fiber that has been optical coupled to a semiconductor laser diode and projecting through free space the expanded beam as a low divergence beam of substantially parallel rays. The laser collimators disclosed are compact, simple to make, and overcome many of the deleterious effects that result from the requirement that the air-glass surface terminating the end of the monomode fiber coupled to the semiconductor laser is not normal to the axis of the optical fiber. Means are also disclosed for increasing the divergence of the cone of light emitted from the tip of an optical fiber thereby enabling the construction of laser collimators with larger expansion ratios in a compact size.

Abstract: The invention discloses an optical deflection switch which uses the output focal plane of a lens more effectively. This is achieved by combining a tapered block of a light-transmissive material having a reflective surface and a second face, wherein the second face includes an input/output port and the reflective surface provides reflection of a beam of light passing through the input/output port into the tapered block with a first block of a light-transmissive material having a first face and a second face, wherein the first face includes an input port thereon for receiving a collimated beam of light and the second face is for providing total internal reflection of the beam of light in a first switching state and for acting as an output/input port for optical communication with the input/output port of the switching block when the total internal reflection is frustrated in a second switching state.

Abstract: A dental implant for anchoring in bone, wherein said bone comprises an outer cortical bone section and an inner cancellous bone section is made of a body of resorbable material such as coral, having a portion capable of being wedged into the cancellous bone. The body of coral has a generally cylindrical root portion, an emergent portion capable of being wedged into said outer cortical bone section, and a transgingival coronal portion being sized to extend beyond said emergent portion to end beyond a gingival layer, and an abutment portion and a head for retention of said prosthetic device at the other end, wherein said abutment portion meets said coronal portion at an interface beyond said gingival layer. The body of coral is substantially electroplated with a suitable plating material such as gold. At least some of the root portion is absent said plating material so as to allow the bone to enter the substantially plated body of coral to resorb and replace at least some of the coral.

Abstract: A sleeve for retaining a plurality of optical fibers in a close or contacting relationship is provided. The sleeve has a bore receiving a number of optical fibers. The internal surface of the bore is such that when that number of optical fibers are contained therein the bore surface defines a perimeter substantially equally spaced about the external surfaces of the optical fibers. Advantageously the sleeve of the present invention may be sealed about the plurality of fibers by vitrification or adhesive to support the fibers or fiber ends without causing unequally distributed stress in the fibers. Signal quality is thus better assured.

Abstract: The present invention relates to a coupling element for coupling between optical elements, for instance a ferrule encased fiber end and a lens, two lenses, or filter and lens assemblies, which provides a reliable joint with a determined spacing and angular orientation between them if needed. Advantageously, the coupling in accordance with the present invention does not obscure optical transmission through the coupling with an epoxy layer. A stand off element is provided which has opposite reference surfaces for joining the end faces of the optical elements and a central aperture, slot or equivalent open area for light transmission. In use the open area is aligned, for example with the fiber end and the desired port in the lens. Adhesive connection can be provided between the opposite surfaces of the stand off element and the coupling end faces of the optical elements. No epoxy is applied over the open area. Other securing methods such as external securing elements can be used.

Abstract: An optical filter is provided having first and second graded index (GRIN) lenses preferably disposed in a coaxial relationship so that they have a common optical axis. Each of the GRIN lenses has an end face providing a port at predetermined location. The ports are disposed on opposite sides of the optical axis and each of the ports is substantially equidistant from the optical axis, so as to be oppositely offset from the optical axis by a same amount. The filter also includes an optical interference filter disposed between other end faces of the first and second graded index lenses. By providing at least four spaced ports, equidistant from the optical axis, such that two ports form a first couplet on opposite sides of the axis from each other and such that two other ports form a second couplet on opposite sides of the axis from each other, wherein one of the ports of one couplet is optically coupled with one of the ports from the other couplet, an add and drop circuit may be realized.

Abstract: A useful device is provided for coupling or splitting optical signals from one port to another. The symmetry of a lens is utilized in a manner whereby two linear arrays of optical ports are disposed adjacent the optical axis of the lens equidistant from the optical axis of the lens. An at least partially reflecting optical element is disposed at a collimating end of the lens. Signals launched into one array of ports reflects back to the second array of ports at the same end. In another embodiment of the invention utilizing these two linear arrays of waveguides, two matched lenses having an element disposed between are used as a coupler/splitter. In this arrangement ports are positioned on opposite sides of the optical axis equidistant from it.