We have demonstrated, the first time to our knowledge, a low-input intensity high-contrast (10:1) optical AND gate based on the differential gain (optical bistability) observed in an 850 nm GaAs vertical-cavity semiconductor optical amplifier (VCSOA). The input switching power is about 6 lW, which equals to the intensity of 16 nW=lm. It is about 2 orders of magnitude lower than in in-plane semi...

In this paper we have numerically analyzed terahertzrange wavelength conversion using nondegenerate four wave mixing (NDFWM) in a SOA integrated DFB laser (experiments reported both in MIT electronics and Fujitsu research laboratories). For analyzing semiconductor optical amplifier (SOA), we use finitedifference beam propagation method (FDBPM) based on modified nonlinear SchrÖdinger equation an...

We report a diode-pumped Yb:KYW amplifier delivering up to 27 mJ pulses at a repetition rate of 100 Hz and a spectral bandwidth of 5.5 nm, centered at around 1030 nm. The system is based on a double-head multipass amplifier configuration where the pump thermal load is distributed over two relatively thin laser crystals, which permits a sufficiently large number of passes with minimal passive lo...

We show, using nonlinearity management, that the optimal performance in high-bit-rate dispersion-managed fiber systems with hybrid amplification is achieved for a specific amplifier spacing that is different from the asymptotically vanishing length corresponding to ideally distributed amplification [Opt. Lett. 15, 1064 (1990)]. In particular, we prove the existence of a nontrivial optimal span ...

We present a transfer-matrix method capable of simulating the effects of nonuniform gratings on the filtering, amplification, and bistability characteristics of distributed feedback (DFB) semiconductor laser amplifiers. The linewidth enhancement factor is incorporated in a way that allows direct gaintuning of the bistability hysteresis. As an example, we compare a /4 phase-shifted DFB amplifier...

A linear, mathematical model of cochlear biomechanics is presented in this paper. In this model, active elements are essential for simulating the high sensitivity and sharp tuning characteristic of the mammalian cochlea. The active elements are intended to represent the motile action of outer hair cells; they are postulated to be mechanical force generators that are powered by electrochemical e...

We describe the principle of operation of an all-optical flip-flop based on dispersive bistability in a distributed feedback semiconductor optical amplifier. Cross-phase modulation controls the photonic bandgap and Bragg resonances of the amplifier, thereby shifting the hysteresis and switching thresholds to higher or lower powers. We give the details of a simple theoretical model that is used ...

Formulas for the noise figure, and the minimum uoisefigure of a multi-link distributed amplifier have been developed. In addition, a relatively simple approximation formula has been devised that predicts the minimum noise figure of a practicaf amplifier design with good accuracy np to frequencies of 9 GHz. Finafly, after the dependence of the noise characteristics on the circnit parameters is d...

This article proposed a simple self cascode RGC amplifier configuration to increase the gain and bandwidth. The cascode amplifier eliminates the miller capacitance between input and output and facilitates high gain, high input and output impedance with high bandwidth. However, the cascode amplifier requires relatively high supply voltage for proper operation and it decreases the output voltage ...

In this paper, based on the coupled-mode and carrier rate equations, a dynamic model and numerical analysis of a multi quantum well (MQW) chirped distributed feedback semiconductor optical amplifier (DFB-SOA)  all-optical flip-flop is precisely derived. We have analyzed the effects of strains of QW and MQW and cross phase modulation (XPM) on the dynamic response, and rise and fall times of the ...