Abstract: The invention relates to a method of aligning magnetic flakes, which includes: coating a substrate with a carrier having the flakes dispersed therein, moving the substrate in a magnetic field so as to align the flakes along force lines of the magnetic field in the absence of an effect from a solidifying means, and at least partially solidifying the carrier using a solidifying means while further moving the substrate in the magnetic field so as to secure the magnetic flakes in the carrier while the magnetic field maintains alignment of the magnetic flakes. An apparatus is provided, which has a belt for moving a substrate along a magnet assembly for aligning magnetic flakes. The apparatus also includes a solidifying means, such as a UV- or e-beam source, and a cover above a portion of the magnet assembly for protecting the flakes from the effect of the solidifying means.

Abstract: A broadband, omnidirectional, multi-layer, dielectric reflector for an LED in a white light emitting device provides both near 100% reflectivity across the visible spectrum of light, and electrical insulation between the substrate and the electrical circuitry used to power and control the LED. When a sealant material, having a higher index of refraction than air, is used to protect the LED and the accompanying electrical circuitry, an aluminum reflector layer or substrate is provided to make up for the loss of reflectivity at certain angles of incidence.

Abstract: An optical device exhibiting a color shift upon rotation is disclosed. The optical device has a textured surface having a relief structure finer than a human eye resolution but large enough not to exhibit diffraction effects. The textured surface is coated with an interference thin film that exhibits a color shift with tilt. A uniform color seen at one angle of rotation changes to another uniform color when the optical device is rotated in its own plane. A method of manufacturing of such an optical device, as well as the use of the optical device as an optical security and authentication element, is also disclosed.

Abstract: A method and apparatus for field spectroscopic characterization of seafood is disclosed. A portable NIR spectrometer is connected to an analyzer configured for performing a multivariate analysis of reflection spectra to determine qualitatively the true identities or quantitatively the freshness of seafood samples.

Abstract: The invention provides a wavelength-controlled pump MOPA laser and a method of operation thereof. A monolithic semiconductor MOPA laser chip has a DFB-laser based MO (master oscillator) and PA (power amplifier) sections formed in a same monolithic waveguide, and separate MO and PA electrodes for individual control of current injection into the MO and PA sections. The laser wavelength is defined by the DFB grating and is kept fixed by suitably controlling the MO current to compensate for a thermal crosstalk from the PA section, or tuned by suitably changing the MO current or direct heating of the DFB region.

Abstract: A multicast optical switch uses a diffractive bulk optical element, which splits at least one input optical beam into sub-beams, which freely propagate in a medium towards an array of directors, such as MEMS switches, for directing the sub-beams to output ports. Freely propagating optical beams can cross each other without introducing mutual optical loss. The amount of crosstalk is limited by scattering in the optical medium, which can be made virtually non-existent. Therefore, the number of the crossover connections, and consequently the number of inputs and outputs of a multicast optical switch, can be increased substantially without a loss or a crosstalk penalty.

Abstract: A polarized light beam having a coherence length L can be depolarized by splitting the beam into orthogonally polarized sub-beams and delaying one of the sub-beams relative to the other by a length larger than L. This spatial delay is created by splitting the beam in a walk-off crystal and disposing in the optical path of one of the sub-beams a slab of an optically dense material, while allowing the other sub-beam to propagate outside and near the slab. The sub-beams remain parallel to each other, allowing another walk-off crystal to be used to recombine the sub-beams. A dual-core fiber ferrule and a microlens array can be used to combine fiber-coupled output beams of two laser diodes in a single compact walk-off crystal.

Abstract: An unaddressed device installed inline in a path of an MPLS network can communicate a packet from within the MPLS network to an upstream device without knowledge of the necessary MPLS labeling by sending the packet intentionally in the wrong direction: downstream. To communicate to an upstream device, the unaddressed device sends a packet downstream into the MPLS network on the opposite side and through the opposite outgoing port from that which would be used for a packet sent to the same device in a non-MPLS network. This behavior forces the MPLS network, when it next inspects the packet, to re-label it with the correct labeling to route the packet on a path back upstream to the recipient device. In this manner, the MPLS architecture is used to redirect or loop back packets from an unaddressed inline device to the upstream device.

Abstract: Multi-mode diode emitters are stacked in a staircase formation to provide a spatially-multiplexed output. Improved coupling efficiency is achieved by providing tilted collimated output beams that determine an effective step height of the stepped structure. Since the effective step height is dependent on the tilt angle, a variable number of emitters can be used inside packages having a same physical step height, while still attaining high coupling efficiency.

Abstract: An aberration corrector and a method to reducing a spherical aberration are disclosed. The aberration corrector has a radial, rotationally symmetric variation of refractive index including a term varying in proportion to a fourth degree of a distance from the optical axis. Since the spherical aberration causes a wavefront deviation proportional to the fourth degree of distance from the optical axis, the spherical aberration can be reduced by the aberration corrector when its thickness causes the exact amount of the phase delay corresponding to the wavefront deviation, but with an opposite sign.

Abstract: An array of laser diode emitters is used as an illumination source for a range imaging system. The laser diode emitters are disposed on a common substrate. When one of the emitters fails, the remaining emitters emit enough light to meet the output optical power specification. The emitters can be disposed with a tight spacing. The tight spacing facilitates packaging of the entire array into a compact single package on a common heat sink.

Abstract: Improved brightness and feedback multi-emitter laser diode modules and methods are provided. A plurality of laser diode emitters emit broad-area light beams in a beam direction. In cross-section, each beam is broad in its slow axis and narrow in its fast axis. Groups of downstream optical components collimate, shape, stack and direct the beams along a light path towards a beam spot (which may be fiber-coupled). After collimating, stacking and directing, the beams are Fourier transformed in the fast-axis through a lens feature having a fast-axis focal length less than about 3 millimeters. In some embodiments, the fast-axis focal length is between about 0.1 and 2.0 millimeters. Astigmatism may be introduced between the fast axis and the slow axis in the beams upstream of the lens feature and in accordance with the fast axis focal length of the lens feature. The emitters may receive feedback including wavelength locking feedback.

Abstract: A fiber coupled semiconductor device and a method of manufacturing of such a device are disclosed. The method provides an improved stability of optical coupling during assembly of the device, whereby a higher optical power levels and higher overall efficiency of the fiber coupled device can be achieved. The improvement is achieved by attaching the optical fiber to a vertical mounting surface of a fiber mount. The platform holding the semiconductor chip and the optical fiber can be mounted onto a spacer mounted on a base. The spacer has an area smaller than the area of the platform, for mechanical decoupling of thermally induced deformation of the base from a deformation of the platform of the semiconductor device. Optionally, attaching the fiber mount to a submount of the semiconductor chip further improves thermal stability of the packaged device.

Abstract: The invention relates to a method and apparatus for evaluating a network and for predicting network performance for a higher order modulation by analyzing network signals modulated using a lower order modulation format. A margin index may be generated for the current or projected modulation formats based on displacement vectors for received symbols to indicate a margin remaining before a codeword error occurs to alert the network operator of potential performance issues before actual codeword errors occur.

Abstract: The invention relates to a method of aligning magnetic flakes, which includes: coating a substrate with a carrier having the flakes dispersed therein, moving the substrate in a magnetic field so as to align the flakes along force lines of the magnetic field in the absence of an effect from a solidifying means, and at least partially solidifying the carrier using a solidifying means while further moving the substrate in the magnetic field so as to secure the magnetic flakes in the carrier while the magnetic field maintains alignment of the magnetic flakes. An apparatus is provided, which has a belt for moving a substrate along a magnet assembly for aligning magnetic flakes. The apparatus also includes a solidifying means, such as a UV- or e-beam source, and a cover above a portion of the magnet assembly for protecting the flakes from the effect of the solidifying means.

Abstract: A time-of-flight (TOF) sensor pixel is provided that performs in-pixel subtraction. The TOF sensor pixel includes a photodetector, a capacitor, and circuitry. The photodetector detects light pulses emitted at a clock frequency, after a time of flight, to provide a photocurrent. The capacitor integrates the photocurrent over an integration period, while the circuitry reverses a flow direction of the photocurrent through the capacitor at twice the clock frequency. At the end of the integration period, the capacitor provides a differential photocharge, corresponding to a capacitor voltage. The capacitor voltage is related to the time of flight of the light pulses and may be used to determine a distance to a target.

Abstract: A method and an apparatus for generating reference signatures in a cellular wireless communications system are provided. A first signature is obtained for a mobile communication unit at a first location. The first signature comprises first location information, a first timestamp, and radio frequency measurement information, but lacks identification information. The first signature is compared to signatures in a database, to identify a second signature having location information and a timestamp corresponding to the first location information and first timestamp. A reference signature is created by combining at least part of the first signature, such as the radio frequency information, with the second signature. The first signature is from an anonymized call. The second signature may be from an application operational on the communication unit, or from a social media website, and may comprise identification information for the communication unit or user.

Abstract: A high field of view, low height package and wafer-level packaging process are provided. The top surface of a first wafer has recesses defined by sidewalls, with a reflector, and a floor. The reflector is incident a horizontal light path form an edge-emitting diode on the floor, directing the light path vertically. A second optically diffusing wafer receives the vertically directed light. A vertical ring to surround each recess is wafer-level fabricated on one of the wafers. The vertical ring may have a high aspect ratio to increase light diffusion. The second wafer is connected above the first such that each vertical ring encloses its corresponding recess and such that the light vertically exits the optically diffusing media after spanning the height of the vertical ring. Diode electrical connections are provided for externally controlling the diode. Individual packages are separated by double-dicing the connected wafers between the recesses.

Abstract: An optical switch platform allowing dual and/or multicast optical switch geometries is disclosed. Only two waveguide arrays are used, one for the input, and one for the output. Multi-row waveguide array(s) can replace individual multiple single-row waveguide arrays for optical switch configurations employing a beam director configured to dispose a plurality of input optical beams in a multi-row pattern of optical beams at an angle-to-offset (ATO) optical element.

Abstract: A plurality of flakes are provided that can be used in ink or paint wherein the flakes are of a size that requires magnification to see their shape, in the form of polygons, such as squares, triangle or rectangles. A breaking or grinding process is used to break a foil into these shaped flakes and frames or walls are provided within the foil sheet so as to delineate the shapes and these lines provided by frames or walls will facilitate breakage in a preferred manner such that the flakes break into selected shaped polygons. Remnants are typically present along flake edges due to the grinding and breakage process however with magnification, one can see the resultant regular polygonal shape. To clearly see the remnants one requires increased magnification and the remnant itself provides a type of signature. It can be seen as a taggent within a taggent.