Abstract:
The present disclosure relates to the field Quantum Key distribution (QKD) and discloses an apparatus (100) and method (300) for adjusting the phase modulator's modulating signal time reference in a phase-based QKD system. The QKD system comprises a pulse generator (10) that generates optical pulses and a phase modulator (20) that modulates the phase of each of the pulses. The apparatus (100) comprises a beam splitter/tap (112), a 1-bit delay interferometer (110), two photodetectors (106,108), and a processing device (104). The splitter feeds the phase modulated optical pulses to the interferometer (110). Two photo detectors are connected to the constructive and destructive output legs (110a,110b) of the interferometer (110). The photo detectors' output are then converted to digital signals and fed to the processing device (104). The processing device (104) measures the average power at both the legs of the interferometer (110) to detect delay between optical signal and modulating signal and adjusts the delay to accurately align the phase modulator (20) with the pulse generator (10).
Abstract:
Methods, systems, and devices for quantum key distribution (QKD) in passive optical networks (PONs) are described. A PON may be a point-to-multipoint system and may include a central node in communication with multiple remote nodes. In some cases, each remote node may include a QKD transmitter configured to generate a quantum pulse indicating a quantum key, a synchronization pulse generator configured to generate a timing indication of the quantum pulse, and filter configured to output the quantum pulse and the timing indication to the central node via an optical component (e.g., an optical splitter, a cyclic arrayed waveguide grating (AWG) router). The central node may receive the timing indications and quantum pulses from multiple remote nodes. Thus, the central node and remote nodes may be configured to communicate data encrypted using quantum keys.
Abstract:
The present invention relates to an IM-DD optical transceiver working with a double-sideband (DSB) and single-sideband (SSB) hybrid signaling. A multicarrier signal using a subcarrier interleaved configuration is transmitted from at least one transmitter towards at least one receiver through at least one optical fiber link. A respective first quality performance of each subcarrier transmitted in a DSB modulation format is compared to a respective second quality performance of each subcarrier transmitted in a SSB modulation format. The modulation format amongst DSB and SSB is respectively selected for each subcarrier as to achieve the better quality performance. A selective filling of each subcarrier can then be obtained in order to get a multicarrier signal free of CD-induced fading dips even after its transmission through the fiber link and an optical-to-electrical conversion at the receiver side.
Abstract:
An RFID reader (500) with a software radio that is aesthetically pleasing and powered using existing electrical systems comprising a component housing (102), a microprocessor (106), a communications protocol IC (108), an RFID interrogator integrated circuit (112), a power source (104), a light source (908), a heat removal means (114) and one or more than one antenna (110) connected to the microprocessor for communicating RDIF data and control data over a non-standard protocol.
Abstract:
The present disclosure discloses a method and an apparatus for hybrid multiplexing/de-multiplexing in a passive optical network, the method comprising steps of: dividing N first intermediate frequency sub-bands averagely into M clusters, wherein each of the clusters contains K first intermediate frequency sub-bands and N=M*K , and wherein each of the K first intermediate frequency sub-bands carries a baseband digital electrical signal; selecting, by a software defined first intermediate frequency multiplexer, the baseband digital electrical signals of K first intermediate frequency sub-bands from the N first intermediate frequency sub-bands for software defined frequency division multiplexing and forming a cluster; and frequency division multiplexing, by an analog hardware cluster multiplexer, analog electrical signals of the M clusters on a second intermediate frequency sub-band. The hybrid analog radio over fiber scheme according to the present disclosure achieves the balance between the software defined intermediate frequency multiplexer and the hardware cluster multiplexer and multi-stage frequency division multiplexing, and has very high cost effectiveness and configuration flexibility.
Abstract translation:本公开公开了一种在无源光网络中进行混合复用/解复用的方法和装置,所述方法包括以下步骤:将N个第一中频子带平均划分成M个簇,其中每个簇包含K个第一中间 频率子带和N = M * K,并且其中K个第一中频子带中的每一个携带基带数字电信号; 由软件定义的第一中频复用器从用于软件定义的频分复用的N个第一中频子带选择K个第一中频子带的基带数字电信号并形成一簇; 以及通过模拟硬件集群多路复用器对第二中频子带上的M个簇的模拟电信号进行频分复用。 根据本公开的混合模拟无线电光纤方案实现了软件定义的中频复用器与硬件集群复用器和多级频分复用之间的平衡,并且具有非常高的成本效益和配置灵活性。
Abstract:
Die Erfindung bezieht sich u. a. auf einen Injektionsmodulator (10) zur Modulation optischer Strahlung (P) mit einem optischen Wellenleiter (20) und einer Diodenstruktur (30), die zumindest zwei p-dotierte Halbleiterabschnitte (110), zumindest zwei n-dotierte Halbleiterabschnitte (210) und mindestens einen schwach oder undotierten Zwischenabschnitt (300) zwischen den p-dotierten und n-dotierten Halbleiterabschnitten (110, 210) aufweist, wobei die p-dotierten Halbleiterabschnitte (110) - in Längsrichtung (L) des Wellenleiters (20) gesehen - gegenüber den n-dotierten Halbleiterabschnitten (210) versetzt angeordnet sind und die Diodenstruktur (30) in einem resonanzfreien Abschnitt des Wellenleiters (20) angeordnet ist, in dem - von Wellenleiterdämpfung abgesehen - die Strahlungsintensität der im Wellenleiter (20) geführten Strahlung (P) konstant ist. Erfindungsgemäß ist vorgesehen, dass die p-dotierten Halbleiterabschnitte (110) auf einer Seite des Wellenleiters (20) - in Längsrichtung (L) des Wellenleiters (20) gesehen und bezogen auf die Wellenleitermitte - liegen, die n-dotierten Halbleiterabschnitte (210) auf der anderen Seite des Wellenleiters (20) liegen und der Zwischenabschnitt (300) im Bereich der Wellenleitermitte liegt, sich die Halbleiterabschnitte (110, 210) jeweils quer zur Wellenleiterlängsrichtung (L) in Richtung der Wellenleitermitte des Wellenleiters (20) erstrecken und die p-dotierten Halbleiterabschnitte (110) - in Längsrichtung (L) des Wellenleiters (20) betrachtet - jeweils mit den n-dotierten Halbleiterabschnitten (210) überlappungsfrei sind.