A memory controller component includes transmit circuitry and adjusting circuitry. The transmit circuitry transmits a clock signal and write data to a DRAM, the write data to be sampled by the DRAM using a timing signal. The adjusting circuitry adjusts transmit timing of the write data and of the timing signal such that an edge transition of the timing signal is aligned with an edge transition of the clock signal at the DRAM.

The present disclosure provides an optical communication drive circuit and method, an optical communication transmitter, an optical communication system, and a vehicle. The optical communication drive circuit includes a clock circuit and a modulation circuit. The clock circuit is configured to output a clock signal with an initial frequency signal as an input under control of information to be transmitted. The clock signal includes alternating first and second frequency signals, the first frequency signal and the second frequency signal having different frequencies and being generated based on the initial frequency signal; and the modulation circuit is configured to modulate an optical signal by the clock signal to obtain a modulated optical signal.

A system and method for synchronizing clocks. The system may include a master device having a reference clock and slave devices whose clocks may be synchronized with the reference clock. The master device may drive a light transmitter (e.g., LED) to produce a light pulse with each clock cycle of the reference clock. The light pluses may be distributed by a transmissive medium, such as a low cost optical fiber.

A charging apparatus for a handheld electronic device includes a housing configured to removably attach to the handheld electronic device. The housing includes at least one electronic logic board, and an accessory station configured to store and charge at least one accessory item of the handheld electronic device. The electronic logic board includes a coil configured to wirelessly provide or accept power to and from the handheld electronic device. A software installed on the electronic logic board is configured to control a power transfer between at least two of the following: the accessory item, the accessory station, the housing, and the handheld electronic device. The housing includes a magnetic material configured to removably attach to a corresponding magnetic material of the handheld electronic device.

A storage system includes a protective housing member configured to mate with a handheld electronic device. The protective housing member includes a charging area formed between a surface of the protective housing member and a surface of an accessory item of the handheld electronic device. The charging area is configured to charge the accessory item of the handheld electronic device. The charging area is powered by at last one power component of the protective housing member or at least one power component of the handheld electronic device. The storage system further includes at least one integrated circuit which is either a component of the handheld electronic device or a component of the protective housing member.

[Problem] To synchronize timings of transmitting and receiving a pulse signal (1 PPS signal) at a constant interval between communication apparatuses even in a case where an optical fiber connecting the communication apparatuses fluctuates in an optical characteristic and an optical fiber length. [Solution] The time synchronization system 20 transmits and receives a pulse signal at a constant interval between a local apparatus L (apparatus L) and a remote apparatus R (apparatus R) connected through the two-core bidirectional optical fibers F1 and F2 to synchronize time. A propagation delay amount τ1 in the fiber F1 is calculated, from a proportional relationship between T1 and T2 and a proportional relationship of τud and τ1, where T1 represents a propagation delay time difference between a pulse signals P1 and P4 of an identical wavelength λ.sub.1 returned after transmitting a pulse signal P1 of wavelength λ.sub.1 and a pulse signal P2 of wavelength λ.sub.2 different from λ.sub.1 to the remote apparatus R, T2 represents a propagation delay time difference between the pulse signal P1 of wavelength λ.sub.1 and a pulse signal P3 of wavelength λ.sub.2, and τud represents the round-trip delay time between the apparatuses L and R. The pulse signals P1 and P2 are transmitted with a time difference td corresponding to a difference between the current and last calculated propagation delay amounts τ1 being set so that the difference is zero.

A storage system includes a protective housing member configured to mate with a handheld electronic device. The protective housing member includes a charging area formed between a surface of the protective housing member and a surface of an accessory item of the handheld electronic device. The charging area is configured to charge the accessory item of the handheld electronic device. The charging area is powered by at last one power component of the protective housing member or at least one power component of the handheld electronic device. The storage system further includes at least one integrated circuit which is either a component of the handheld electronic device or a component of the protective housing member.

A method for entropy scaling in quantum random number generators, comprising dividing one spatial mode into multiple spatial modes, delaying each spatial mode, and recombing the spatial modes; detecting first temporal states with synchronisation to a photon generation time and encoding the first temporal states into first time bins; detecting second temporal states in an arbitrary clock, and encoding the second temporal states into second time-bins. The method comprises dividing a source of single photons into two paths in a first beam splitter and recombining the two paths in a next beam splitter, repeatedly, in a cascade of n beam splitters, consecutive beam splitters being separated by a length of fiber, yielding a number I=2.sup.n of temporal states for each photon; detecting first temporal states by measuring a photon rate in a temporal window selected to measure photon arrival times, with synchronisation to a generation time of the photons, and encoding the first temporal states into first time bins, a number of the first temporal states being I=2.sup.n; detecting second temporal states by measuring a photon rate in the selected temporal window, in absence of synchronisation to the generation time of the photon, and encoding the second temporal states into second time-bins, a number of the second time bins being N.sub.v; thereby generating a state space for each photon of N.sub.v×I.

A system for transceiving data based on a clock transition time is provided. A transmitting device included in the system includes at least one first transmitting circuit configured to transmit data via a wired channel by changing a clock transition time based on the data, wherein the at least one first transmitting circuit includes a skew controller configured to output a skew clock generated by controlling a duty ratio and a skew of an input clock, and a phase-difference modulator configured to output a transmission signal including information about the data generated by changing a transition time of the skew clock based on the data.

A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.