the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...

For the future of optical communication systems, Digital signal processing (DSP) is an enabling technology. This system is the most promising widely viewed in the next generation for long-haul transport systems. In past, the digital carrier phase estimation demonstration in coherent receivers has stimulated an extensive attention in coherent optical communications again. In this paper, the emer...

The important meaning of the optical fiber connector scratches detection was introduced based on wavelet packet and machine vision. To detect the optical fiber connector scratches by using the UltraPAC system, aiming at the scratches feature, the method of analyzing and extracting the scratches eigenvalue by using wavelet packet analysis and pattern recognition by making use of the wavelet neur...

A novel three-dimensional probing technique for microparts with high aspect ratios is proposed. In this technique, a particle trapped optically at the optical fiber tip is used as a probe for position detection. In order to confirm the feasibility of this method, this paper demonstrates numerical computations about the optical force exerted on the probe sphere and the behavior of position detec...

A novel microplasma generator based on ceramic chips has been developed and coupled with optical emission spectrometry through orthogonal detection. Stable microplasma was generated between two electrodes in the ingroove discharge chamber and the optical fiber was set in perpendicular to the gas outlet to collect emitted light. The emission signal of CN is surprisingly enhanced by reacting carb...

Non linear effects play a major role in hindering the progress of optical communication systems in terms of higher data rates and long haul transmissions. Maximum Likelihood Sequence Detection (MLSD) has been proposed to combat the nonlinear effects in optical channels. The main objective is to extract the original signal from the received signal which is distorted due to the non linear effects...

Signal optimization is affected during radio links between a transmitter and a receiver located in adjacent material media with differing optical densities. The optimization is carried out via the automated control theory method. The radio signal obtained after the optimization is coordinated with the two media's electrical characteristics simultaneously; and this enables low power and small an...

We propose and demonstrate tunable homodyne detection using nonlinear optical signal processing to automatically lock a “local” pump laser to an incoming 20-to-40-Gbaud QPSK data signal. Open eyes are obtained for both in-phase and quadrature components of the signal after ~200km transmission over SMF-28 and DCF fibers. The BER performance of the proposed homodyne detection scheme is also compa...

Hydrogen detection is essential for its implementation as an energy vector. So far, palladium is considered to be the most effective hydrogen sensing material. Here we show that palladium-capped hafnium thin films show a highly reproducible change in optical transmission in response to a hydrogen exposure ranging over six orders of magnitude in pressure. The optical signal is hysteresis-free wi...