Abstract: A computer-implemented method comprising receiving a plural number of candidate parameter value sets in a specified order, each comprising a respective candidate parameter value for at least one parameter of an optimisation algorithm, wherein the number of candidate parameter value sets is based on a processing budget; for each candidate parameter value set in the sequence: applying the optimisation algorithm, with the at least one parameter set to the respective candidate parameter value, to a plurality of initial states of a model representing a system to generate corresponding candidate updated states, and evaluating each of the candidate updated states according to an optimality metric to generate a corresponding optimality score; selecting, as an estimated optimal state of the model, the candidate updated state having the highest optimality score; and outputting the selected estimated optimal state of the model to a user interface, network interface or other application.

Abstract: A method of performing a write operation in a holographic data storage system, in which schedule schedules at least one write operation across multiple non-contiguous write intervals, the write operation pertaining to a set of data to be stored in a region of a holographic recording medium. In each of the non-contiguous write intervals, the region of the holographic recording medium is exposed to an interference pattern caused by interference between a reference beam and an input beam carrying the set of data. The multiple non-contiguous write intervals have a total aggregate duration of sufficient length to cause a persistent state change in the exposed region, such that the set of data is recoverable from that region by the end of a final write interval of the multiple non-contiguous write intervals.

Abstract: In an optical data transfer system, a beam modulator is configured to embed a set of data in an input beam. A multimode optical waveguide network has an in-coupling region for receiving the input beam. The multimode optical waveguide network is configured to guide the input beam to an out-coupling region of the multimode optical waveguide network. A spatial coherent detector is configured to measure a phase and an amplitude of an output optical field at multiple locations. The output optical field is at least partially defined by the input beam and thus exhibiting distortion effects caused by the passage of the beam through the multimode waveguide network. Signal processing is applied to an output of the spatial coherent detector, in order to compensate for the distortion effects, and thereby recover, from the output of the spatial coherent detector, the set of data embedded in the input beam.

Abstract: A multimode optical waveguide network comprises a parent waveguide and a plurality of child waveguides. Each waveguide is a multimode optical waveguide having a first surface region, multiple second surface regions, and at least one guiding element attached to a surface of the waveguide or embedded within the waveguide, each second surface region of the parent waveguide optically coupled to the first surface region of a corresponding child waveguide. The guiding element(s) of the parent waveguide is arranged to guide a beam, from or to its first surface region, to or from any selected second surface region of its multiple second surface regions. The guiding element(s) of each of the waveguides is configurable for selecting the second surface region of that waveguide and/or responsive to at least one beam characteristic for selecting the second surface region of that waveguide via modulation of the at least one beam characteristic.

Abstract: A multimode optical waveguide network comprises a parent waveguide and a plurality of child waveguides. Each waveguide is a multimode optical waveguide having a first surface region, multiple second surface regions, and at least one guiding element attached to a surface of the waveguide or embedded within the waveguide, each second surface region of the parent waveguide optically coupled to the first surface region of a corresponding child waveguide. The guiding element(s) of the parent waveguide is arranged to guide a beam, from or to its first surface region, to or from any selected second surface region of its multiple second surface regions. The guiding element(s) of each of the waveguides is configurable for selecting the second surface region of that waveguide and/or responsive to at least one beam characteristic for selecting the second surface region of that waveguide via modulation of the at least one beam characteristic.

Abstract: Apparatus for performing vector-by-vector multiplication in an optical domain, comprising: a plurality of light signal generators, each arranged to emit a beam of light having a different respective carrier wavelength modulated with an input signal modelling a respective variable of a vector of variables; one or more sets of light modulator elements, wherein each light modulator element in each set is arranged to receive the beam of light modulated with a different one of said input signals, and apply a corresponding weight from a vector of weights in order to produce a weighted optical signal; a respective photosensor element for each of said sets; and one or more optical combining elements arranged to direct the weighted optical signals of each set onto the respective photosensor element and thereby produce a respective output in the form of an analogue electronic signal summing the weighted optical signals of the respective set.

Abstract: A system for performing optical vector multiplication, the system comprising one or more channels, each comprising: a light signal generator arranged to generate a respective optical signal; an optical vector multiplier arranged to receive a vector of optical signals including the respective optical signal, and multiply by a respective vector of weights in the optical domain, each optical signal having a modulated amplitude modelling a value of a respective variable from a vector of variables, and the weights modelling interactions between the variables; and a light detector arranged to detect an intensity of a resulting output of the respective optical vector multiplier by incoherent detection, thereby generating an analogue intensity signal taking only take positive values; and a respective differentiator configured to subtract a respective DC offset signal from the analogue intensity signal, to produce a respective analogue electronic output signal on a scale having positive and negative values.

Abstract: A server system comprising processing devices, disks and a storage fabric, all arranged to operate according to a storage fabric protocol in order to communicate between the processing devices and the storage devices over the storage fabric, wherein the storage fabric is settable with a mapping determining which of the processing devices are allocated to use which of the storage devices in providing said services to the client systems. The system comprises a control function arranged to dynamically adapt the mapping in response to either: (i) failure or other downtime of one of the processing devices, storage devices, a component of the storage fabric or a connection in the storage fabric; or (ii) a current demand for the services from the client systems.

Abstract: In an optical data transfer system, a beam modulator is configured to embed a set of data in an input beam. A multimode optical waveguide network has an in-coupling region for receiving the input beam. The multimode optical waveguide network is configured to guide the input beam to an out-coupling region of the multimode optical waveguide network. A spatial coherent detector is configured to measure a phase and an amplitude of an output optical field at multiple locations. The output optical field is at least partially defined by the input beam and thus exhibiting distortion effects caused by the passage of the beam through the multimode waveguide network. Signal processing is applied to an output of the spatial coherent detector, in order to compensate for the distortion effects, and thereby recover, from the output of the spatial coherent detector, the set of data embedded in the input beam.

Abstract: A server system comprising processing devices, disks and a storage fabric, all arranged to operate according to a storage fabric protocol in order to communicate between the processing devices and the storage devices over the storage fabric, wherein the storage fabric is settable with a mapping determining which of the processing devices are allocated to use which of the storage devices in providing said services to the client systems. The system comprises a control function arranged to dynamically adapt the mapping in response to either: (i) failure or other downtime of one of the processing devices, storage devices, a component of the storage fabric or a connection in the storage fabric; or (ii) a current demand for the services from the client systems.

Abstract: A method of performing a write operation in a holographic data storage system, in which schedule schedules at least one write operation across multiple non-contiguous write intervals, the write operation pertaining to a set of data to be stored in a region of a holographic recording medium. In each of the non-contiguous write intervals, the region of the holographic recording medium is exposed to an interference pattern caused by interference between a reference beam and an input beam carrying the set of data. The multiple non-contiguous write intervals have a total aggregate duration of sufficient length to cause a persistent state change in the exposed region, such that the set of data is recoverable from that region by the end of a final write interval of the multiple non-contiguous write intervals.

Abstract: A storage library system comprises a plurality of slots for storing items, a plurality of rails, and a robot for interacting with said items. The robot has at least two foot arrangements each having a respective gripping mechanism for releasably engaging that foot arrangement with the rails. The robot also has a transfer mechanism for moving the robot, while a first one or more of the foot arrangements remains engaged with a first of the rails, from a first position in which one or more of the foot arrangements is in abutment with a second of the rails to a second position in which one or more of the foot arrangements is in abutment with a third of the rails. The robot also has an end-effector for interacting with the items in the slots.

Abstract: Examples are disclosed that relate to encoding data on a data-storage medium. The method comprises obtaining a representation of a measurement performed on the data-storage medium, the representation being based on a previously recorded pattern of data encoded in the data-storage medium in a layout that defines a plurality of data locations. The method further comprises inputting the representation into a data decoder comprising a trained machine-learning function, and obtaining from the data decoder, for each data location of the layout, a plurality of probability values, wherein each probability value is associated with a corresponding data value and represents the probability that the corresponding data value matches the actual data value in the previously recorded pattern of data at a same location in the layout.

Abstract: In an optical data transfer system, a beam modulator is configured to embed a set of data in an input beam. A multimode optical waveguide network has an in-coupling region for receiving the input beam. The multimode optical waveguide network is configured to guide the input beam to an out-coupling region of the multimode optical waveguide network. A spatial coherent detector is configured to measure a phase and an amplitude of an output optical field at multiple locations. The output optical field is at least partially defined by the input beam and thus exhibiting distortion effects caused by the passage of the beam through the multimode waveguide network. Signal processing is applied to an output of the spatial coherent detector, in order to compensate for the distortion effects, and thereby recover, from the output of the spatial coherent detector, the set of data embedded in the input beam.

Abstract: A method of performing a write operation in a holographic data storage system, in which schedule schedules at least one write operation across multiple non-contiguous write intervals, the write operation pertaining to a set of data to be stored in a region of a holographic recording medium. In each of the non-contiguous write intervals, the region of the holographic recording medium is exposed to an interference pattern caused by interference between a reference beam and an input beam carrying the set of data. The multiple non-contiguous write intervals have a total aggregate duration of sufficient length to cause a persistent state change in the exposed region, such that the set of data is recoverable from that region by the end of a final write interval of the multiple non-contiguous write intervals.

Abstract: A holographic data storage system comprises an emitter system, a holographic recording medium, and an input waveguide network formed of one or more multimode optical waveguides. The holographic recording medium has multiple recording regions, each optically coupled to a corresponding one of multiple out-coupling regions of the input waveguide network, the holographic data storage system arranged to persistently write data of an input beam, received at any one of the out-coupling regions, to the corresponding recording region. A controller is coupled to at least one of the emitter system and at least one controllable guiding element of the input waveguide network and controls at least one optical characteristic of the input beam or the at least one guiding element, so as to guide the input beam from an in-coupling region to any selected one of the multiple out-coupling regions. Similar waveguide networks are provided for carrying reference and output beams.

Abstract: A system for estimating values of a vector of variables that optimize a function comprising a weighted sum of interactions between the variables; the system comprising a plurality of parallel hardware channels, each arranged to model a contribution of a respective variable to the function, each channel comprising: a signal generator configured to generate a signal modelling a value of the respective variable; a splitter arranged to supply the signal to each of the channels; interaction logic configured to multiply the vector of signals by a vector of weights modelling an interaction between the respective variable and the vector of variables, thereby generating a feedback signal representing the contribution of the respective variable; and a feedback path to return the feedback signal to the signal generator configured to adapt the signal in dependence on the feedback signal, wherein each channel is implemented only using optical components and/or analogue electronic components.

Abstract: A holographic data storage system comprises an emitter system, a holographic recording medium, and an input waveguide network formed of one or more multimode optical waveguides. The holographic recording medium has multiple recording regions, each optically coupled to a corresponding one of multiple out-coupling regions of the input waveguide network, the holographic data storage system arranged to persistently write data of an input beam, received at any one of the out-coupling regions, to the corresponding recording region. A controller is coupled to at least one of the emitter system and at least one controllable guiding element of the input waveguide network and controls at least one optical characteristic of the input beam or the at least one guiding element, so as to guide the input beam from an in-coupling region to any selected one of the multiple out-coupling regions. Similar waveguide networks are provided for carrying reference and output beams.

Abstract: An apparatus comprising: a crystal; a wire pair formed of a first wire connected so as to receive a first alternating current, and a second wire connected so as to receive a second alternating current substantially antiparallel to the first alternating current in the first wire, and located adjacent the first wire such that a localized electromagnetic filed is created in a region local to the wire pair via constructive electromagnetic interference between the first wire and the second wire in the region local to the wire pair and destructive electromagnetic field interference between the first wire and the second wire outside of the region local to the wire pair; and a colour centre located within the crystal in the region local to the wire pair.

Abstract: An apparatus comprising: a crystal; and a colour centre located within the crystal and adapted to receive: a magnetic field, such that a projection of the magnetic field onto a colour centre axis of the colour centre causes a change in an electron spin resonance frequency of the colour centre, and an electromagnetic signal having a frequency that substantially matches the electron spin resonance frequency of the colour centre as changed by the projection of the magnetic field onto the colour centre axis.