Abstract: A method of writing voxels to a substrate using a laser writing system comprises forming a first voxel at a first position in a substrate using a first laser pulse; detecting light emitted or scattered by the substrate as a result of forming the first voxel; determining whether the detected light satisfies a predetermined constraint; and, when the detected light does not satisfy the predetermined constraint, adjusting an amplitude of a second laser pulse. Light emission or scattering from the substrate as a result of forming a voxel is related to the properties of the formed voxel. By monitoring such emission or scattering, it is made possible to compensate for variations in performance of the laser writing system. Also provided herein are a laser writing system and computer program product which implement the method.

Abstract: A method of writing data to a transparent substrate comprises forming a first voxel by focusing a first laser pulse on a first location in a transparent substrate; and forming a second voxel by focusing a second laser pulse on a second location in the transparent substrate. The first laser pulse and the second laser pulse have different amplitudes, resulting in the first and second voxels having different strengths. Also provided are a system useful for implementing the method; an optical data storage medium obtainable by the method; and a method of reading data from the optical data storage medium.

Abstract: A method for forming birefringent voxels comprises simultaneously generating a first seed pulse and a first data pulse. The first seed pulse and the first data pulse are spatially-separated laser pulses having different amplitudes. The first seed pulse is focused at a first seed location, and the data pulse is focused at a first data location. The first seed location and the first data location are separated by a predetermined distance along a scan path, with the first seed location being ahead of the first data location. Subsequently, a second seed pulse and a second data pulse are generated, and focused at a second seed location and second data location, respectively. The second seed and data locations are separated by the predetermined distance. The second data location is the same as the first seed location, resulting in formation of a birefringent voxel.

Abstract: A switching network for effecting point-to-point communication between nodes has a time-varying switching configuration, which causes successive activation and deactivation of multiple channels of the switching network, a first of the channels connecting, when activated, a transmitter node and a first receiver node, and a second of the channels connecting, when activated, the transmitter node and a second receiver node.

Abstract: A switching network for effecting point-to-point communication between nodes has a time-varying switching configuration, which causes successive activation and deactivation of multiple channels of the switching network, a first of the channels connecting, when activated, a transmitter node and a first receiver node, and a second of the channels connecting, when activated, the transmitter node and a second receiver node.

Abstract: A switching network for effecting point-to-point communication between nodes has a time-varying switching configuration, which causes successive activation and deactivation of multiple channels of the switching network, a first of the channels connecting, when activated, a transmitter node and a first receiver node, and a second of the channels connecting, when activated, the transmitter node and a second receiver node.

Abstract: In various examples there is a communications network comprising a plurality of nodes connected via an interconnection medium to form a receive-from-many communications network. The network has a synchronisation mechanism which synchronizes a signal frequency of the nodes. The network has at least one store holding signal amplitude data of signals previously sent between specified pairs of nodes of the communications network. An amplitude controller uses the stored data to adjust amplitudes of signals communicated between at least one of the pairs of nodes of the communications network.

Abstract: A wavelength switchable laser is described which has a multi-wavelength laser source configured to generate signals at different wavelengths. The wavelength switchable laser has a wavelength selector with a plurality of electro-optical switches, each electro-optical switch being configurable to transmit or block output of one of the signals from the multi-wavelength source according to the wavelength of the signal.

Abstract: In various examples there is a communications network comprising a plurality of nodes connected via an interconnection medium to form a receive-from-many communications network. The network has a synchronisation mechanism which synchronizes a signal frequency of the nodes. The network has at least one store holding signal amplitude data of signals previously sent between specified pairs of nodes of the communications network. An amplitude controller uses the stored data to adjust amplitudes of signals communicated between at least one of the pairs of nodes of the communications network.

Abstract: A method of checking messages from a network of communication sources includes initially testing the signal strength of a plurality of communication sources, storing the identity of the communication sources with the two strongest signals, and alternatively entering a sleep mode and a wake-up mode, the wake-up mode synchronized to the communication source with the strongest signal. The method further includes testing the signal strength of one additional communication source, switching synchronization to the additional communication source if said source presents a signal stronger than the signal of a stored communication source with the strongest signal, and replacing the identity of any stored communication source if an additional communication sources tested in sequence presents a signal stronger than the signal of said stored communication source.

Abstract: A method of checking messages from a network of communication sources includes initially testing the signal strength of a plurality of communication sources, storing the identity of the communication sources with the two strongest signals, and alternatively entering a sleep mode and a wake-up mode, the wake-up mode synchronized to the communication source with the strongest signal. The method further includes testing the signal strength of one additional communication source, switching synchronization to the additional communication source if said source presents a signal stronger than the signal of a stored communication source with the strongest signal, and replacing the identity of any stored communication source if an additional communication sources tested in sequence presents a signal stronger than the signal of said stored communication source.

Abstract: A vehicle locating unit with improved power management. A receiver receives a signal from a network of communication sources. A signal strength monitoring subsystem determines which of the communication sources are transmitting the strongest signals. A power management subsystem is responsive to the signal strength monitoring subsystem and is configured to alternatively enter sleep and wake-up modes, synchronize the wake-up mode to the communication source transmitting the strongest signal, and test the signal strength of at least one additional communication source according to a predefined sequence.

Abstract: A vehicle locating unit with a receiver for receiving a signal from a network of communication sources, a transponder activated when a communication source sends a message to the receiver, and a power supply regulating circuit for regulating a nominal input voltage and powering the receiver and the transponder. A protection circuit is responsive to an injected input voltage and configured to clamp the injected (high level) input voltage at a predetermined maximum voltage.