XOR performance of a quantum dot semiconductor optical amplifier based Mach-Zehnder interferometer

Abstract

The performance of all-optical XOR gate based on quantum-dot (QD) SOA MZI has been simulated. The saturation power, optical gain and phase response of a QD SOA has been analyzed numerically using a rate equation model of quantum dots embedded in a wetting layer. The calculated response is used to model the XOR performance. For the parameters used here, XOR operation at ~ 250 Gb/s is feasible using QD based Mach-Zehnder interferometers. The speed is limited by the relaxation time from wetting layer to the quantum dots.

Performance Analysis of a High-Speed All-Optical Subtractor using a Quantum-Dot Semiconductor Optical Amplifier-Based Mach-Zehnder Interferometer

“…Many designs for a single subtractor or subtractor with adder have been proposed by using a semiconductor optical amplifier (SOA) and periodically-poled lithium niobate (PPLN) waveguide [4], micro-ring resonator [5], exploiting four-wave mixing (FWM) in a SOA [6], a SOA based-Mach-Zehnder interferometer (MZI) [7], a three-state system [8], a terahertz optical asymmetric demultiplexer (TOAD) [9], a single-slot waveguide [10], two SOAs [11], implementing nonlinear material [12], and a nonlinear directional coupler [13]. SOA with quantum-dot active region is a promising candidate for ultrafast operations [14][15]. The high output power, low threshold current density, ultra-fast response behavior, good temperature stability, and low noise level of the quantum-dot SOA (QD-SOA) have been demonstrated, and it has been emphasized that these elements can be utilized as building blocks of alloptical systems [17][18][19].…”

All-optical Data Extraction Based on Optical Logic Gates

“…In this paper, the suggested optical system based on SOAs shows the potential for high speed, and highly integrable and low power optical data computing. [4][5][6][7][8][9] . 지는 실제 시스템에 적용 가능한 기술들의 충분한 확보가 미 흡한 실정이다 [10][11][12][13] .…”

New Approach to Ultra-Fast All-Optical Signal Processing Based on Quantum Dot Devices

“…In particular, MZI with a SOA inserted in each arm is characterized by a high on-off contrast and the output converted signal consisting of the exact replica of the incident signal Agrawal (2002). All-optical logic operations are important for all-optical signal processing Sun (2005). Alloptical logic gates operation is based on nonlinearities of optical fibers and SOAs.…”

“…However, the disadvantages of optical fibers are weak nonlinearity, long interaction length, and/or high control energy required in order to achieve a reasonable switching efficiency Sun (2005). On the contrary, SOAs, and especially QD-SOAs, possess high nonlinearity, small dimensions, low energy consumption, high operation speed, and can be easily integrated into photonic and electronic systems Sun (2005), Hamié (2002), Kanellos (2007), Dong (2008). The major problems of the improving transmission optical systems emerge from the signal-tonoise ratio (SNR) degradation, chromatic dispersion, and other impairment mechanisms Zhu (2007).…”

“…We investigated theoretically different regimes of RZ optical signal operation for such a processor and carried out numerical simulations. We developed a realistic model of QD-SOA taking into account two energy levels in the conduction band of each QD and a Gaussian distribution for the description of the different QD size Ben-Ezra (2007), Ben-Ezra (2009), unlike the one-level model of the identical QDs recently used Berg (2004a), Sun (2005). We have shown that the accurate description of the QD-SOA dynamics predicts the high quality output signals of the QD SOA-MZI based logic gate without significant amplitude distortions up to a bit rate of about 100Gb/s for the bias current I = 30mA and 200Gb/s for the bias current I = 50mA being limited by the relaxation time of the electron transitions between the wetting layer (WL), the excited state (ES) and the ground state (GS) in a QD conduction band Ben-Ezra (2009).…”