Four-wave mixing is one of the major degradation effects in fiber optic systems with dense channel spacing and low chromatic dispersion on the fiber. In the long-distance wavelength-division multiplexing (WDM) optical communication system, the cross talk generated from four-wave mixing in optical fibers limits the performance of the system, which can be controlled for non-linearity purposes in optical telecommunication, especially the channel wavelengths are set near the zero-dispersion wavelength of optical fibers. Hence, a very short fiber segment with an ultrahigh non-linearity is useful to support the FWM. In this paper, the experimental set-up of compact fiber ring laser based different lengths of nonlinear Bismuth-Erbium doped fiber (Bi-EDF, 181 and 215 cm) is employed by using four-wave mixing (FWM) method. These two gain nonlinear media have been successfully used to stabilize a dual-wavelength fiber laser with and without nonlinear photonic crystal fiber (PCF) at room temperature through the degenerate four-wave mixing effect for γ,and n2 estimation of non-linear parameters and FWM efficiency of optical fiber. The exclusive and practical benefits of using the high non-linear bismuth-erbium doped fiber (Bi-EDF) in implementing a FWM applications for non-linear PCF parameters are experimentally demonstrated. Besides, the FWM effect can be also employed for signal amplification, phase conjugation, wavelength conversion, and high-speed optical switching. Coupled interaction of Bi-EDF and PCF fiber in FWM scattering explain the unique feature of the proposed configuration.

Background: Intrauterine growth restriction (IUGR) refers to fetuses with an estimated ultrasonography weight below the 10% percentile. Hypoglycemia is a major concern in neonates with IUGR. Objective: To investigate the relationship between umbilical artery (UA) Doppler ultrasonography and neonate hypoglycemia and IUGR. Materials and Methods: This was a longitudinal follow-up study consisting of 114 neonates (gestational age of 28-40 wk) born with IUGR in the third trimester of pregnancy at Shahid Sadoughi Hospital, Yazd, Iran between May 2016 and October 2017. The neonates were assigned into three subgroups of normal UA Doppler, absent end-diastolic flow (EDF) in UA Doppler, and reverse EDF in UA Doppler. The blood glucose of the neonates was checked one, two, three, six, 12, 24 and 48 hr after birth, and the neonates were placed in the hypoglycemia or euglycemia groups according to guidelines. Results: Out of the 114 neonates included in the study, 75 (65. 8%) had normal UA Doppler, 29 (25. 4%) had absent EDF in UA Doppler, and 10 (8. 8%) had reverse EDF in UA Doppler. There was a significant difference in the mean blood glucose in the first hr between the normal UA Doppler group and the reverse EDF in UA Doppler group (p < 0. 01). Conclusion: Postnatal hypoglycemia in neonates with IUGR is associated with the result of UA Doppler ultrasonography during pregnancy.

Raman amplification of a 49 cm Bismuth oxide (Bi2O3) as a nonlinear gain medium based erbium doped fiber amplifier (EDFA) is reported in new and compact design in near infrared spectral regions. The bismuth glass host provides the opportunity to be doped heavily with erbium ions to allow a compact optical gain fiber amplifier design by using reduced fiber length and the 1480 nm low pump power around 150 mW. A extended Raman amplification bandwidth of 45 nm, from 1520-1565 nm (C-band window) wavelengths is empirically proposed in a backward and dualwavelength pumped Bi-EDF by employing 350 mW Raman pump in 1440 nm. Because of the short length gain medium as a nonlinear Bi-EDF, amplification of 3 dB is achieved over a C-band wavelength range. This simple C-band Raman amplifier based Brillouin and ASE backscattering was constructed to test the forward, backward and dual-wavelength pump laser and on-off gain. A peak gain of 1. 53 dB was obtained with a 3-dB bandwidth of 45 nm that the varieties of gain is 2. 02 dB around 1545 nm in backward pumping design. It array will be employ for sensing, spectroscopy and telecommunication systems.

Recently, a large set of electroencephalography (EEG) data is being generated by several high-quality labs worldwide and is free to be used by all researchers in the world. On the other hand, many neuroscience researchers need these data to study different neural disorders for better diagnosis and evaluating the treatment. However, some format adaptation and pre-processing are necessary before using these available data. In this paper, we introduce the SecondBrain as a new lightweight and simplified module that can easily apply various major analysis on EEG data with common data formats. The characteristics of the SecondBrain shows that it is suitable for everyday usage with medium analyzing power. It is easy to learn and accept many data formats. The SecondBrain module has been developed with Python and has the power to windowing data, whitening transform, independent component analysis (ICA), downloading the public datasets, computing common spatial patterns (CSP) and other useful analysis. The SecondBrain, also, employs a common spatial pattern (CSP) to extract features and classifying the EEG MI-based data through support vector machine (SVM). We achieved a satisfactory result in terms of speed and performance.