in this paper first we try to analysis the behavior ofthe soas in the optical networks and then have proposed anumerical simple model to simulate the behavior of thesemiconductor optical amplifiers. after that by employing thismodel as inline amplifier for a dwdm optical system, we havesimulated the transmission of 10 channels with bit rate 10 gb/sup to distance 3970 km with rz-dpsk modulation ...

A generic M-ary continuous phase modulation (CPM) scheme, with a modulation index of h = M 1 , can be decomposed into a continuous-phase encoder (CPE) followed by a memoryless modulator (MM), where the CPE is linear over the ring of integers modulo M (M being the code radix). Thus, for a binary CPM scheme, M = 2 while for a quaternary scheme, M = 4. By designing a channel encoder (CE), which is...

This work is the first demonstration of electrical modulation of surface energy to reversibly switch dynamic high-speed gas-liquid two-phase microfluidic flow patterns. Manipulation of dynamic two-phase systems with continuous high-speed flows is complex and interesting due to the multiple types of forces that need to be considered. Here, distinct stable flow patterns are formed through a multi...

A mono-component is a real-valued signal of finite energy that has non-negative instantaneous frequencies, which may be defined as the derivative of the phase function of the given real-valued signal through the approach of canonical amplitude-phase modulation. We study in this article how the amplitude is determined by its phase in a canonical amplitude-phase modulation. Our finding is that su...

Common-mode voltage (CMV) generated by the inverter causes motor bearing failures in multiphase drives.On the other hand, presence of undesired z-component currents in six-phase induction machine (SPIM) leads to extra current losses and have to be considered in pulse width modulation (PWM) techniques. In this paper, it is shown that the presence of z-component currents and CMV in six phase driv...

The frequency-domain mode comb of a Ti:sapphire femtosecond laser centered at 350 THz is broadened to 150 THz (full width at -30 dBc) by self-phase modulation in a single-mode optical fiber. By phase locking continuous-wave lasers to elements of the comb near 1064 and 778 nm, we measure the 104-THz frequency gap between these two lasers with a relative uncertainty of 2.7 x 10(-11) in 1 s.

We disclose the vertically aligned deformed helix ferroelectric liquid crystal whose Kerr constant (Kkerr≈130  nm/V2 at λ=543  nm) is around one order of magnitude higher than any other value previously reported for liquid crystalline structures. Under certain conditions, the phase modulation with ellipticity less than 0.05 over the range of continuous and hysteresis-free electric adjustment of...

This paper addresses the general problem of finding the combination of code rates and continuous phase modulation (CPM) parameters that have the best energy efficiency for a given spectral efficiency and demodulator complexity. More specifically, bit-interleaved coded modulation (BICM) with noncoherently detected M -ary Gaussian frequency shift keying (GFSK) is considered for the fading channel...

Abstract |We consider carrier phase and symbol timing synchronization for M-ary partial-response continuous phase modulation (CPM).We focus on developing a classical phase locked loop (PLL)-basedmethod that is robust even forM-ary partial-response CPMs, which has proven to be elusive thus far in the literature. A key part of our design is a simple yet ešective timing false lock detector, which ...

We present a comparison of two low-noise carrier-envelope offset (CEO) frequency stabilization methods studied using an ytterbium (Yb) fiber laser oscillator based on nonlinear amplifying loop mirror. first investigate the phase locking performance achieved with cross-gain modulation (XGM) via injection auxiliary low-power continuous-wave (CW) into gain medium. Amplification injected CW light c...