Ultra-wideband discrete Raman amplifier optimization for single-span S-C-L-band coherent transmission systems

We experimentally compare the performance of two key ultra-wideband discrete Raman amplifier structures, a cascaded dual-stage structure and an in-parallel dual-band structure, in fully loaded S-C-L band coherent transmission systems over 70 km of single-mode fiber. Our results show that dual-band discrete Raman amplifier with minimized backreflections can effectively avoid unstable random distributed feedback lasing, reduce the noise figure, and therefore improve the transmission performance for signals at shorter wavelengths, versus the cascaded dual-stage structure. The average noise figure for S-band signals is 6.8 dB and 7.2 dB for the dual-band structure and cascaded dual-stage structure, respectively, while the average S-band Q2 factor is similarly improved by 0.6 dB. Moreover, the cascaded dual-stage discrete Raman amplifier requires guard bands around the 1485-nm and 1508-nm pumps as the signal and pump wavelengths overlap, which results in a bandwidth loss of ∼10 nm and reduces the potential net data throughput to 28.6 Tb/s for 30-GBaud DP-16QAM signals. However, the dual-band structure can utilize the bandwidth more effectively, which leads to a higher estimated net data throughput of 31.2 Tb/s

Sustainable economic development : concept, principles and management from Islamic perspective

The basic concern of development in Islamic economic system is on human welfare. This is in line with the very basic objective of Islamic jurisprudence (Shari’ah ) which puts important to the welfare of the people and their relief from hardship. Economic development should be consistent with this central objective of shari`ah. The center for development process in Islam relies on man as an economic agent. It is man to be educated on the entire development process by integrating sosial development, economic development and environmental conservation and protection. This paper attempts to explain the concept, principles and management of sustainable economic development from Islamic perspective. The paper would start by defining the concept of sustainable economic development and development goals. Next, the Islamic principles for sustainable economic development would be discussed, followed by the discussion on the management of sustainable economic development from Islamic perspective. In conclusion, the paper strongly suggests the economic development process to fully adhere to the Islamic principles as the key for sustainable development which covers both the material and non-material aspects of life. Keywords: Sustainable development, Economic development, management, Islamic economics, economic syste

Analysis of a distributed fiber-optic temperature sensor using single-photon detectors

We demonstrate a high-accuracy distributed fiber-optic temperature sensor using superconducting nanowire single-photon detectors and single-photon counting techniques. Our demonstration uses inexpensive single-mode fiber at standard telecommunications wavelengths as the sensing fiber, which enables extremely low-loss experiments and compatibility with existing fiber networks. We show that the uncertainty of the temperature measurement decreases with longer integration periods, but is ultimately limited by the calibration uncertainty. Temperature uncertainty on the order of 3 K is possible with spatial resolution of the order of 1 cm and integration period as small as 60 seconds. Also, we show that the measurement is subject to systematic uncertainties, such as polarization fading, which can be reduced with a polarization diversity receiver

High Power, Continuous-wave Supercontinuum Generation in Highly Nonlinear Fibers Pumped with High Order, Cascaded Raman Fiber Amplifiers

A novel method for efficient generation of high power, equalized continuous-wave supercontinuum source in an all conventional silica fiber architecture is demonstrated. Highly nonlinear fiber (HNLF) is pumped in its anomalous dispersion region using a novel, high power, L-band laser. The L-band laser encompasses a 6th order cascaded Raman amplifier which is pumped with a high power Ytterbium doped fiber laser and amplifies a low-power, tunable L-band seed source. The supercontinuum generated 35W of power with ~40% efficiency. The Supercontinuum spectrum was measured to have a high degree of flatness of better than 5 dB over 400 nm of bandwidth (1.3 - 1.7 micron, limited by spectrum analyzer range) and a power spectral density in this region of >50 mW/nm. The extent of the SC spectrum is estimated to be upto 2 micronComment: 6 pages, 5 figure

Machine learning-based Raman amplifier design

A multi-layer neural network is employed to learn the mapping between Raman gain profile and pump powers and wavelengths. The learned model predicts with high-accuracy, low-latency and low-complexity the pumping setup for any gain profile.Comment: conferenc

Applied constant gain amplification in circulating loop experiments

The reconfiguration of channel or wavelength routes in optically transparent mesh networks can lead to deviations in channel power that may impact transmission performance. A new experimental approach, applied constant gain, is used to maintain constant gain in a circulating loop enabling the study of gain error effects on long-haul transmission under reconfigured channel loading. Using this technique we examine a number of channel configurations and system tuning operations for both full-span dispersion-compensated and optimized dispersion-managed systems. For each system design, large power divergence was observed with a maximum of 15 dB at 2240 km, when switching was implemented without additional system tuning. For a bit error rate of 10-3, the maximum number of loop circulations was reduced by up to 33%