scholarly journals Enhancing the heralded single-photon rate from a silicon nanowire by time and wavelength division multiplexing pump pulses

2015 ◽  
Vol 40 (11) ◽  
pp. 2489 ◽  
Author(s):  
X. Zhang ◽  
I. Jizan ◽  
J. He ◽  
A. S. Clark ◽  
D.-Y. Choi ◽  
...  
Author(s):  
Yuanhua Li ◽  
Xianfeng Chen

Single-photon frequency conversion for quantum interface plays an important role in quantum communications and networks, which is crucial for the realization of quantum memory, faithful entanglement swapping and quantum teleportation. In this chapter, we will present our recent experiments about single-photon frequency conversion based on quadratic nonlinear processes. Firstly, we demonstrated spectrum compression of broadband single photons at the telecom wavelength to the near-visible window, marking a critical step towards coherent photonic interface. Secondly, we demonstrated the nonlinear interaction between two chirped broadband single-photon-level coherent states, which may be utilized to achieve heralding entanglement at a distance. Finally, we theoretically introduced and experimentally demonstrated single-photon frequency conversion in the telecom band, enabling switching of single photons between dense wavelength-division multiplexing channels. Moreover, quantum entanglement between the photon pair is maintained after the frequency conversion. Our researches have realized three significant quantum interfaces via single-photon frequency conversion, which hold great promise for the development of quantum communications and networks.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Fabian Beutel ◽  
Helge Gehring ◽  
Martin A. Wolff ◽  
Carsten Schuck ◽  
Wolfram Pernice

AbstractQuantum key distribution (QKD) can greatly benefit from photonic integration, which enables implementing low-loss, alignment-free, and scalable photonic circuitry. At the same time, superconducting nanowire single-photon detectors (SNSPD) are an ideal detector technology for QKD due to their high efficiency, low dark-count rate, and low jitter. We present a QKD receiver chip featuring the full photonic circuitry needed for different time-based protocols, including single-photon detectors. By utilizing waveguide-integrated SNSPDs we achieve low dead times together with low dark-count rates and demonstrate a QKD experiment at 2.6 GHz clock rate, yielding secret-key rates of 2.5 Mbit/s for low channel attenuations of 2.5 dB without detector saturation. Due to the broadband 3D polymer couplers the reciver chip can be operated at a wide wavelength range in the telecom band, thus paving the way for highly parallelized wavelength-division multiplexing implementations.


Author(s):  
BHADRA ANAMIKA ◽  
SAHU VIKAS ◽  
SHRIVASTAVA SHARAD MOHAN ◽  
ANSHU ◽  
SANGHVI ANJALI S. ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Georg Rademacher ◽  
Benjamin J. Puttnam ◽  
Ruben S. Luís ◽  
Tobias A. Eriksson ◽  
Nicolas K. Fontaine ◽  
...  

AbstractData rates in optical fiber networks have increased exponentially over the past decades and core-networks are expected to operate in the peta-bit-per-second regime by 2030. As current single-mode fiber-based transmission systems are reaching their capacity limits, space-division multiplexing has been investigated as a means to increase the per-fiber capacity. Of all space-division multiplexing fibers proposed to date, multi-mode fibers have the highest spatial channel density, as signals traveling in orthogonal fiber modes share the same fiber-core. By combining a high mode-count multi-mode fiber with wideband wavelength-division multiplexing, we report a peta-bit-per-second class transmission demonstration in multi-mode fibers. This was enabled by combining three key technologies: a wideband optical comb-based transmitter to generate highly spectral efficient 64-quadrature-amplitude modulated signals between 1528 nm and 1610 nm wavelength, a broadband mode-multiplexer, based on multi-plane light conversion, and a 15-mode multi-mode fiber with optimized transmission characteristics for wideband operation.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Anurupa Lubana ◽  
Sanmukh Kaur ◽  
Yugnanda Malhotra

AbstractIn this work, we study and analyze the performance of Raman + Erbium-Ytterbium codoped fiber hybrid optical amplifier (HOA) for an ultradense wavelength division multiplexing (UD-WDM) system having 100 channels. The system has been investigated considering initial values of channel spacing and data rate of 0.1 nm (12.5 GHz) and 100 GB/s, respectively. Initially, the two important WDM system parameters—wavelength and channel spacing—have been selected and then optimization of the proposed HOA has been performed in terms of EYDFA length, pump power and Er+ concentration to achieve higher values of average gain, Q-factor and lower gain variation ratio. The optimized configuration of the HOA results in the achievement of higher value of average gain, Q-factor and gain variation ratio of 47 dB, 14 and 0.14, respectively, which confirms its viability for UD-WDM system applications.


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