Abstract: An optical grating comprising a refractive index with a periodic pattern that includes a base period ?0; a periodic sampling of the base period, with a first period ?1 and a first duty cycle p1, thereby defining a single-sampled grating (SSG); and a periodic sampling of the SSG, with a second period ?2 and a second duty cycle p2. The resulting dual-sampled grating (DSG) can have a reflection spectrum containing reflection peaks. If two DSGs having different reflection spectra share a common interface, a tunable optical filter can be produced, where electrical or heating means can cause a reflection peak of one spectrum to be shifted to coincide with a reflection peak of the other spectrum, thereby filtering the corresponding wavelength. By inserting between the two DSGs a gain medium and a phase-tuning medium, a laser source structure is realized. Either device can be produced by etching or stacking methods.

Abstract: A method, apparatus and system for medium access control is provided. Time slots configured to include mini slots at the beginnings thereof. Devices are assigned time slot, mini slot combinations as transmission opportunities. A device can attempt to use a transmission opportunity when it has a packet to send, by beginning data transmission in its assigned slot and mini slot and potentially continuing the transmission up until the end of the assigned slot. If another device is already transmitting in the assigned slot, the device refrains from using its transmission opportunity. Higher priority devices can be assigned transmission opportunities corresponding to earlier mini slots within a slot. In some embodiments, multiple devices can be assigned the same transmission opportunity and a collision detection mechanism can be employed. In some embodiments, all devices detect if a slot is idle and advance the beginning of the next slot upon such detection.

Abstract: An optical fiber configured to improve the pump conversion efficiency of an L-band fiber amplifier which uses the multimode pump source. By directly absorbing multimode light including 915 nm, an active fiber core region co-doped with both erbium and ytterbium can provide gain to the L-band signals via stimulated emission. The unwanted C-band amplified spontaneous emission (ASE) light generate from this active fiber core region can be absorbed by another active fiber core region doped with erbium, then provides additional gain to the L-band signals. Active regions and cladding can be configured to match a given spatial mode of the optical signal. Signal-pump combiners with end-coupling or side coupling can be used.

Abstract: System and method for improving performance in an optical link. The optical link includes a plurality of communication channels for transmitting an optical signal. The method is performed by a link controller of the optical link. The method comprises determining a noise level of at least one channel of the plurality of channels, determining a launch power offset for the at least one channel and performing link commissioning based at least in part on the launch power offset.

Abstract: Methods, devices, and processor-readable media for scaling up graphical user interface (GUI) elements on a smart watch touchscreen based on the initial position of a stroke gesture, thereby facilitating selection, by a user, of a target GUI element. The user only needs to perform one stroke action to select the desired target. During the procedure, GUI elements of the main screen are scaled up to make target selection easier, and the GUI elements are automatically reset to their original size when the procedure is complete. To achieve this result, a “stroke with initial position” gesture is used to select a target.

Abstract: A pixel for creating an optical phase change includes a transparent electrical insulator, a first electrical conductor disposed on the transparent electrical insulator, the first electrical conductor comprising an antenna component and a connector component, an electrical insulator disposed on the first electrical conductor, a transparent semiconductor disposed on the electrical insulator, and a second electrical conductor disposed on the transparent semiconductor. The transparent semiconductor is sufficiently thick to prevent plasmonic resonance from occurring at an interface between the transparent semiconductor and the second electrical conductor.

Abstract: A method of beamforming by which a signal can be received into an array of channels, each of which is split into a real-part sub-channel and an imaginary part sub-channel. In each sub-channel, optical waves are used to carry the signal via waveguides. Each channel includes a real-part sub-channel where an optical wave is scaled by the real part of a complex number, and an imaginary part sub-channel, where a complementary optical wave is scaled by the complex part of the same complex number. When the complementary optical waves are received at the channel's output, they can be shifted by the phase of the complex number having defined their scaling. By processing a signal with a system operative to perform such method, the application of a different phase to each channel can result in a beamforming of the signal.

Abstract: A method of quantum key distribution making use of 2-qubit entanglement, by which one entangled qubit is sent from an operator O to Alice and the other entangled qubit is sent from operator O to Bob, making for key-sharing among three parties (multi-user quantum key distribution, i.e. MU QKD). Alice and Bob each measures a respective sequence of qubits randomly along either one of two states, records the measurements in a respective list, and encodes the bits in an encoded list. The encoded lists are sent to operator O for entanglement to be verified with the CHSH inequality. Bob's verified list is sent to Alice and vice-versa, allowing Alice and Bob to further verify correlation. Non-entangled bits are rejected until Alice and Bob have a similar key, being a reconciled quantum-based key as sought.

Abstract: Embodiments of the present disclosure generally provide for a method and apparatus for performing computations using mixed-mode memory elements having contents which are accessible via both optical and electrical interactions. In particular, an array of such elements are accessed through a “crossbar” array structure which includes both an optical crossbar array structure an electrical crossbar array structure. Applications to machine learning, e.g. neural network training, are also provided for.

Abstract: Methods of distributing a quantum-based cryptographic key to multiple network nodes. A multi-user quantum key distribution from one node to two further nodes can be extended to a binary tree structure where any further node can participate in quantum key distribution with its two child nodes. A key generated in a 3-node subgroup can be stitched with a key from of a parent 3-node subgroup, or a child 3-node group, and key confirmations can be provided through authenticated classical channels. Classical channels can also be used to communicate and relay membership updates, allowing a key operator at a binary tree's root node to update keys accordingly.

Abstract: Layers of a neural network can be implemented on an analog computing platform operative to perform MAC operations in series or in parallel in order to cover all elements of an arbitrary size matrix. Embodiments include a convolutional layer, a fully-connected layer, a batch normalization layer, a max pooling layer, an average pooling layer, a ReLU function layer, a sigmoid function layer, as well as concatenations and combinations. Applications include point cloud processing, and in particular of the processing of point clouds obtained as part of a LiDAR application. To implement elements of point cloud data as optical intensities, the data can be linearly translated in order to be fully represented with non-negative values.

Abstract: A method, apparatus and system for medium access control is provided. Time slots configured to include mini slots at the beginnings thereof. Devices are assigned time slot, mini slot combinations as transmission opportunities. A device can attempt to use a transmission opportunity when it has a packet to send, by beginning data transmission in its assigned slot and mini slot and potentially continuing the transmission up until the end of the assigned slot. If another device is already transmitting in the assigned slot, the device refrains from using its transmission opportunity. Higher priority devices can be assigned transmission opportunities corresponding to earlier mini slots within a slot. In some embodiments, multiple devices can be assigned the same transmission opportunity and a collision detection mechanism can be employed. In some embodiments, all devices detect if a slot is idle and advance the beginning of the next slot upon such detection.

Abstract: Some embodiments of the present disclosure provide a deep-learning-based framework for designing components of a downlink precoding system. The components of such a system include downlink training pilots and channel estimation based on receipt of the downlink training pilots. Another component involves channel measurement and feedback strategy at the user equipment. The components include a precoding scheme designed at the base station based on the feedback from the user equipment.

Abstract: A method to obtain a cache miss ratio curve where a memory blocks of a cache have variable block sizes. By stacking sets of counters, each set being for a different block size, a stack distance for variable block sizes can be obtained and used to determine a miss ratio curve. Such curve can then be used to select a cache size that is appropriate for an application without requiring excessive memory. Methods can be used for batches of request, can apply limits to block sizes, and rounding for intermediary block sizes, they can be used with pruning, and their space complexity can be held constant.

Abstract: For a given application, increasing the size of a cache is beneficial up to a certain point and the number of hits does not increase significantly with a greater cache size. This disclosure provides a method to determine a miss ratio curve, for a cache having data blocks with a time-to-live. A hashed value of a data block's key address can be used to generate a 2D HLL counter for storing expiry times of the data blocks. The 2D HLL counter can be converted to a 1D array, from which a stack distance can be calculated. A frequency distribution of stack distances can then be converted into a miss ratio curve, from which an appropriate cache size can be selected.

Abstract: The present invention relates to highly polarizable 3D organic perovskites of the general formula ABX3, prepared by introducing halogen functional groups in the A-site cation (in which the A and B sites are occupied by organic cations and the X site is a monovalent non-metallic counterion). The (DCl)(NH4)(BF4)3 crystal exhibits a strong linear electrooptic (EO) effect with an effective EO coefficient of 20 pmV?1, which is 10 times higher than that of metal halide perovskites. These 3D organic perovskites are solution processed and compatible with silicon, and illustrate the potential of rationally-designed all-organic perovskites for use in on-chip modulators, electro-optic devices, piezoelectric devices, or silicon photonics devices.

Abstract: An optical fiber comprises a core having an elliptical cross section and a cladding having a circular cross section. The core has an aspect ratio between 2 and 40. The core and the cladding have a common central axis with the core being enclosed by the cladding. The difference of a refractive index of the cladding to a refractive index of the core is between 1×10?2 and 1.5×10?1. A trench is located between the core and the cladding. The trench has a uniform width and encircles the core. The refractive index of the trench is lower than the refractive index of the cladding.

Abstract: A method is disclosed of mounting a heat sink through a printed circuit board to reach a component on the opposite side of a board. The heat sink is passed through a window in the board to contact a component at a predetermined pressure optimized for thermal performance at minimum stress. The heat sink is affixed in place on the printed circuit board using through-hole pins which can be soldered to maintain the heat sink's position and the predetermined pressure.

Abstract: In cloud computing, for various reasons such as load-balancing, hotspot elimination, server consolidation, energy and cost savings, and system maintenance, there is a need to migrate a virtual sub-network of virtual entities from a source network of servers to a destination set of servers. Existing migration methods are limited to the migration of VM memory and controller states, where network entities are migrated individually. Embodiments of this disclosure include systems and methods for the stateful live migration of a multi-layer network, while maintaining live state convergence and consistency, and preventing network connection losses, packet disordering and packet drops.

Abstract: According to a first aspect of the disclosure, methods are discussed in which a station (STA) sends a message to an access point, for example an associated access point, about a change in multi-AP coordination parameters. A STA, which may be a mobile STA, can be in a better position than the APs themselves, for detecting changes in conditions which can affect the effectiveness, or even the desirability of the multi-AP coordination. Accordingly the STA can send a message reporting detected conditions related to multi-AP coordination. In some embodiments, such a message can request for initializing multi-AP coordination, such a message can be in response to a triggering event detected by the STA. In response to such a triggering event, the STA can analyze the STA's service needs, and send the message about a change in multi-AP coordination parameters. A second aspect of the disclosure provides an AP-to-AP negotiation process for multi-AP coordination.