Rafael C. Figueiredo

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An ultrafast electro-optical amplified switch based on chip-on-carrier semiconductor optical amplifier with high optical contrast (33 dB) is presented. Switching times up to 115 ps with small overshoot were achieved by using the multi-impulse step injected current technique. These results are compared with previous preimpulse step injected current(More)
Based on a diode-laser model, this paper presents the equivalent electrical circuit above and below the transparency condition for a chip (unpackaged) semiconductor optical amplifier. The modeling and parameters extraction were obtained as a function of the bias current, achieving good agreement between theoretical and experimental results in a wide(More)
A simple heterodyne scheme with digital data acquisition and offline signal processing is introduced to obtain phase noise spectra and linewidths of monomode lasers. The data are analyzed using time-domain memorized signals, enabling the evaluation of parameters such as coherence time, phase noise, laser linewidth as a function of bias current, and the(More)
Experimental and simulated results of an amplified electro-optical spatial switch using pre-emphasis techniques are presented. A symmetrical thin-film resistor replaces the typical 47&#x00A0;<inline-formula><tex-math notation="LaTeX"> $\Omega$</tex-math></inline-formula> resistor used to match the impedance between the device (<inline-formula> <tex-math(More)
The present paper describes a microwave mount (up to 40 GHz) with fiber facility inside an optical table for chip tests. Semiconductor optical amplifier (SOA) switching times of a chip-on-carrier (unpackaged) SOA were tested with rise times below 100 ps. It could be useful for a variety of SOA and photonic devices tests for electro-optical high-speed(More)
We investigate some key requirements for PAM4 operation at 56 Gbaud focusing on short-reach intra-data center interconnect. We report simulated results of bandwidth limitations for transmitter and receiver sides components with and without pulse shaping, presenting the penalties imposed in each scenario. We also evaluate chromatic dispersion tolerance for(More)
We experimentally demonstrate single-wavelength 56-GBd PAM4 transmission at 1550 nm, without chromatic dispersion compensation in the optical domain, focusing on short-reach intra data center applications. We obtained an extended-reach of 33% employing low-complexity digital equalizers and maximum likelihood sequence estimation, achieving error-free(More)
Remote applications are becoming widely used in various fields such as industry, education, and security. This paper presents a low cost system to monitor and control laboratory instruments remotely by Short Message Service (SMS). The system has been designed using the National Instruments Laboratory Virtual Instrument Engineering Workbench (LabVIEW)(More)
The transient and steady state performances of optical space switches based on semiconductor optical amplifiers (SOAs) switching an optical carrier modulated in amplitude through several switching techniques and operating parameters were characterized. The analysis was focused on the switch's guard time, resulting from the sum of its rise time and ringing(More)
Experimental sweep frequency results of electro-optical conversion for a chip-on-carrier and for a packaged semiconductor optical amplifiers are presented up to the fifth harmonic. Influence from electrical bias current, spectral components, and input power are analyzed. The experimental results illustrate the influence of electrical parasitic elements in(More)