Bit-rate-variable and order-switchable optical multiplexing of high-speed pseudorandom bit sequence using optical delays

2010 ◽  
Vol 35 (18) ◽  
pp. 3042 ◽  
Author(s):  
Xiaoxia Wu ◽  
Jian Wang ◽  
Omer F. Yilmaz ◽  
Scott R. Nuccio ◽  
Antonella Bogoni ◽  
...  
Keyword(s):  
High Speed ◽  
Bit Rate ◽  
Optical Multiplexing ◽  
Optical Delays

scholarly journals Systematic Performance Comparison of (Duobinary)-PAM-2,4 Signaling under Light and Strong Opto-Electronic Bandwidth Conditions

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 81
Author(s):  
Ramón Gutiérrez-Castrejón ◽  
Md Ghulam Saber ◽  
Md Samiul Alam ◽  
Zhenping Xing ◽  
Eslam El-Fiky ◽  
...  
Keyword(s):  
Optical Networks ◽  
High Speed ◽  
Performance Comparison ◽  
Sampling Point ◽  
Bit Rate ◽  
Performance Limits ◽  
Specific System ◽  
Rate System ◽  
Modulation Formats ◽  
Modulation Format

We present a systematic comparison of PAM-2 (NRZ), Duobinary-PAM-2, PAM-4, and Duobinary-PAM-4 (duo-quaternary) signaling in the context of short-reach photonic communications systems using a Mach–Zehnder modulator as transmitter. The effect on system performance with a relaxed and constrained system’s opto-electronic bandwidth is analyzed for bit rates ranging from 20 to 116 Gb/s. In contrast to previous analyses, our approach employs the same experimental and simulation conditions for all modulation formats. Consequently, we were able to confidently determine the performance limits of each format for particular values of bit rate, system bandwidth, transmitter chirp, and fiber dispersion. We demonstrate that Duobinary-PAM-4 is a good signaling choice only for bandwidth-limited systems operating at relatively high speed. Otherwise, PAM-4 represents a more sensible choice. Moreover, our analysis put forward the existence of transition points: specific bit rate values where the BER versus bit rate curves for two different formats cross each other. They indicate the bit rate values where, for specific system conditions, switching from one modulation to another guarantees optimum performance. Their existence naturally led to the proposal of a format-selective transceiver, a component that, according to network conditions, operates with the most adequate modulation format. Since all analyzed modulations share similar implementation details, signaling switching is achieved by simply changing the sampling point and threshold count at the receiver, bringing flexibility to IM/DD-based optical networks.

Efficient and universal quantum key distribution based on chaos and middleware

2017 ◽  
Vol 31 (02) ◽  
pp. 1650264 ◽  
Author(s):  
Dong Jiang ◽  
Yuanyuan Chen ◽  
Xuemei Gu ◽  
Ling Xie ◽  
Lijun Chen
Keyword(s):  
Quantum Key Distribution ◽  
High Speed ◽  
Key Distribution ◽  
Secure Communications ◽  
Bit Rate ◽  
Chaotic Cryptography ◽  
Secret Keys ◽  
Middleware Technology ◽  
Universal Quantum ◽  
The Many

Quantum key distribution (QKD) promises unconditionally secure communications, however, the low bit rate of QKD cannot meet the requirements of high-speed applications. Despite the many solutions that have been proposed in recent years, they are neither efficient to generate the secret keys nor compatible with other QKD systems. This paper, based on chaotic cryptography and middleware technology, proposes an efficient and universal QKD protocol that can be directly deployed on top of any existing QKD system without modifying the underlying QKD protocol and optical platform. It initially takes the bit string generated by the QKD system as input, periodically updates the chaotic system, and efficiently outputs the bit sequences. Theoretical analysis and simulation results demonstrate that our protocol can efficiently increase the bit rate of the QKD system as well as securely generate bit sequences with perfect statistical properties. Compared with the existing methods, our protocol is more efficient and universal, it can be rapidly deployed on the QKD system to increase the bit rate when the QKD system becomes the bottleneck of its communication system.

Development of Ferroelectric Data Storage Test System for High-Density and High-speed Read/Write

2009 ◽  
Vol 1199 ◽  
Author(s):  
Yoshiomi Hiranaga ◽  
Kenkou Tanaka ◽  
Tomoya Uda ◽  
Yuichi Kurihashi ◽  
Yasuhiro Kimoto ◽  
...  
Keyword(s):  
Thin Film ◽  
Data Storage ◽  
High Speed ◽  
Test System ◽  
Control Technique ◽  
Recording Media ◽  
Bit Rate ◽  
Recording Medium ◽  
Storage Test ◽  
Nonlinear Dielectric

AbstractIn this study, we have developed ferroelectric data storage test systems based on scanning nonlinear dielectric microscopy (SNDM) to conduct various experiments concerning read/write capability. Nanodomain formation on ferroelectric recording media was studied using the data storage test system. A nanodomain dot array was successfully written on a single-crystal LiTaO3 recording medium. The diameter of the written dot was as small as 7 nm. Epitaxial-thin-film LiTaO3 recording media were also developed. Nanodomain dots with the diameter of 25 nm were written on the thin-film recording medium. In addition, a non-contact probe-height control technique was adopted to solve the problem of tip abrasion using higher-order nonlinear dielectric response detection method. Finally, a hard-disk-drive (HDD)-type ferroelectric data storage test system was developed for conducting read/write tests under conditions close to those of actual operation. Capabilities of reading at the bit rate of 2 Mbps and writing at the bit rate of 20 Mbps were confirmed using the HDD-type data storage test system.

scholarly journals Advancing High-Speed Transmissions over OCDMA Networks by Employing an Intelligently Structured Receiver for Noise Mitigation

2018 ◽  
Vol 8 (12) ◽  
pp. 2408 ◽  
Author(s):  
Kai-Sheng Chen ◽  
Yi-Chang Chen ◽  
Long-Guang Liao
Keyword(s):  
Interference Cancellation ◽  
High Speed ◽  
Noise Suppression ◽  
Optical Signal ◽  
Spectral Amplitude ◽  
Light Sources ◽  
Bit Rate ◽  
Noise Mitigation ◽  
Compact Structure ◽  
Code Division Multiple

We propose an intelligently structured receiver to achieve high-speed transmissions over optical code-division multiple access (OCDMA) networks. Employing spectral-amplitude coding (SAC) reduces multiuser interference (MUI) in OCDMA, but the network bit-rate is limited by phase-induced intensity noise (PIIN) coming from the incoherency of light sources. To mitigate PIIN, the receiver performs interference estimations and regenerations through consecutive stages. The MUI is removed by subtracting the estimated interference term from the received multiplexed signals. For PIIN variance, it is both dependent on and positively related to user number and bit-rate. Reducing the number of interference users allows the network to support transmissions with a higher speed under a given noise level. The proposed scheme has the advantages of all-optical signal processing and a compact structure. Additionally, the function of noise suppression is rarely studied in the existing MUI elimination schemes, such as serial interference cancellation (SIC) and parallel interference cancellation (PIC). The simulation results show the proposed receiver achieves significant increment in bit-rate than the conventional balanced detector in SAC–OCDMA networks.

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