Optical Amplifier Based Mach-Zehnder Interferometer Research Articles

Comparative study of all-optical INVERTER and BUFFER gates using MZI structure

Abstract In the paper, one input optical gates i.e., INVERTER and BUFFER have been designed using some basic assumption to analyze with the help of Semi-conductor Optical Amplifier based Mach–Zehnder Interferometer structure. The results are optimized by iterative process. The proposed design of optical gates presents low complexity, high scalability and more feasible to evaluate through digital Boolean analyzation. The digital Boolean analyzation is analyzed by some basic Boolean rules and assumptions which makes the design more digital so that it can be compatible for more than one input optical gates also. Optical Gate is designed to get constructive and destructive interference for pump and probe as they are injected into SOA simultaneously. The phase modulation is converted into intensity modulation which gives a Boolean result. The paper is optimized by Eye diagram, Q factor, wavelength spectrum and frequency chirp for both the gates. The comparative results of extinction ratio for both the gates have also been discussed. The design is supported by theoretical analysis, simulation tool (Optsim) and Boolean explanation. The proposed designs are constructed with same pattern which supports the same Boolean analysis.

Design and analysis of all-optical half-adder, half-subtractor and 4-bit decoder based on SOA-MZI configuration

In the paper, all-optical Boolean circuits implemented with a semiconductor optical amplifier based Mach–Zehnder interferometer, are simulated and analyzed at 10 Gb/s to extract a simple design rule. Authors propose the novel designs of half-adder, half-subtractor and 4-bit decoder for various results and also discussed the results at different bit rates. In the designs, one data acts as a pump generated through clock wave laser and another acts as a probe from mode lock laser. The designs consist of non-linearity in semiconductor optical amplifier using the cross gain modulation technique. Cross gain modulation refers to data on pump signal modulating the carrier density in semiconductor optical amplifier. At the same time, the gain variation indentation inverts the probe signal after passing through amplifier. Interferometer structure is used to convert the phase modulation into intensity modulation. The paper aims to achieve the goal through simulation and Boolean analysis in terms of gates, to provide simple design rule. Obtained results are very useful in the design of other more complex all-optical circuits that employ the given gates as the basic building block. The extinction ratio is the optimization criteria for all the three circuits at different values of pump power and bit rate of input pulse.

5 GHz all-optical binary counter employing SOA-MZIs and an optical NOT gate

We present an all-optical two-bit binary counter using two stages of optical T-flip-flop (T-FF) and an optical NOT Gate. The T-FF comprises a single semiconductor optical amplifier based Mach–Zehnder interferometer (SOA-MZI) and an external feedback loop. The NOT gate is realized by means of the cross gain modulation effect in an SOA. The proposed counter requires the minimum number of active components and just a single control signal as input. Featuring distinctive simplicity for reduced footprint and low power consumption, it is ideal for photonic integration and operation at multi-Gb s−1 speeds.

All-optical modulation format conversion from NRZ-OOK to PSK-Manchester using SOA-MZI

Proposed and demonstrated is an all-optical modulation format conversion from a non-return-to-zero on-off keying (NRZ-OOK) signal to a phase-shift keying (PSK)-Manchester format signal using a semiconductor optical amplifier based Mach-Zehnder interferometer (SOA-MZI). In the experiment, a 2.5 Gbit/s PSK-Manchester format signal was obtained from a NRZ-OOK signal and a 50 km error-free transmission of the converted PSK-Manchester format signal was achieved. In addition, the feasibility of the conversion at a higher data rate using SOAs with fast phase recovery was investigaged.

Jitter and Amplitude Noise Accumulations in Cascaded All-Optical Regenerators

This paper proposes and demonstrates a simulation model to systematically investigate jitter accumulations in cascaded all-optical 2R regenerators. The simulation results indicate that when the pattern dependence from the memory effect is minimized, the jitter accumulation depends critically on the degree of the regenerative nonlinearity. Studies of tradeoffs between the jitter from bandwidth limitation and the signal-to-noise-ratio degradation help identify the optimized regenerator bandwidth for various degrees of regenerative nonlinearity. The simulation then considers the pattern dependence from the memory effect and finds that it can severely degrade the cascadability of an optical 2R regenerator and can make it worse than that of a linear optical amplifier (optical 1R). The simulation results show good matches to the experimental results of an optical 2R regenerator based on a semiconductor optical amplifier based Mach-Zehnder interferometer. To overcome the jitter accumulation associated with the optical 2R regeneration, we experimentally demonstrate an optical 3R regenerator for optical nonreturn-to-zero signals with all-optical clock recovery. The experiments achieve more than 1000-hop cascadability for pseudorandom binary sequence 231-1 inputs with a 100-km recirculation loop using lab fiber. Field trial experiments then demonstrate a more than 1000-hop cascadability for a 3R spacing of 66 km and a 100-hop cascadability for a 3R spacing of 264 km.

A compact all-optical subcarrier label-swapping system using an integrated EML for 10-Gb/s optical label-switching networks

We propose a compact and simple all-optical subcarrier-multiplexed (SCM) label-swapping system employing an integrated electroabsorption modulation laser and a semiconductor optical amplifier based Mach-Zehnder interferometer wavelength converter. The experiments demonstrated error-free all-optical label swapping for the 155-Mb/s label and 10-Gb/s payload over two optical label-switching network nodes with less than 0.7-dB power penalty on the payload. The majority of the components in this SCM label-swapping system can be realized on a semiconductor platform (e.g., InP), which implies a step toward possible monolithic or hybrid integration of the all-optical label-swapping system in the future.

All-optical multi-wavelength conversion of 10 Gbit∕s NRZ∕RZ signals based on SOA-MZI for WDM multicasting

An all-optical multi-wavelength converter using a semiconductor optical amplifier based Mach-Zehnder interferometer is proposed and demonstrated. The proposed scheme can accommodate both NRZ and RZ format. WDM multicasting is confirmed by transmission experiment using conventional singlemode fibre before and after the multi-wavelength converter.

Self-starting photonic clock using semiconductor optical amplifier based Mach-Zehnder interferometer

A novel self-starting photonic clock device is proposed. The device generates photonic clock signals passively by utilising cross-phase modulation in a DC biased semiconductor optical amplifier based Mach-Zehnder interferometer (SOA-MZI) with optical feedback loop(s) and a continuous-wave laser source. Generation of a 950 MHz clock signal is demonstrated.

All-Optical OTDM Add/Drop Multiplexing using Semiconductor Optical Amplifier based Mach-Zehnder Interferometer with improved Extinction Ratio

Article All-Optical OTDM Add/Drop Multiplexing using Semiconductor Optical Amplifier based Mach-Zehnder Interferometer with improved Extinction Ratio was published on August 1, 2001 in the journal Journal of Optical Communications (volume 22, issue 4).

Simultaneous all-optical add and drop multiplexing of 40 Gbit/s OTDM signals using monolithically integrated Mach-Zehnder interferometer

A monolithically integrated semiconductor optical amplifier based Mach-Zehnder interferometer has been used to demonstrate for the first time simultaneous all-optical add/drop operations for 40 Gbit/s OTDM signals. The penalty for the add operation is 1.3 dB.