An all-optical Sampler for digitising Radio-over-Fibre transceivers

Abstract

In this paper it is proposed and designed an alloptical Sampler (o-Sampler) intended to be part of future optical Digitising Radio-over-Fibre (o-DRoF) transceivers. It is based on the Semiconductor Laser Amplifier Loop Mirror (SLALOM) configuration thus using the nonlinearities of a semiconductor optical amplifier (SOA) in cross-switching regime. The proof-ofprinciple is established by computer simulations using 500 MHz analogue signal and 2.5 GS/s sampling pulses both in the C-band. The proposed o-Sampler outputs real-time generated optical samples from an analogue RoF signal. The simulated device is rather compact, polarisation independent, potentially optically integrable and requires few mW of sampling peak power.

Sagnac loop incorporating a semiconductor optical amplifier without bias current to receive/modulate weak RF signals

“…This was feasible due to the partial recovery gain typical of resonant optical nonlinearity of SOAs. Even though it is not explored in this paper, the device here described may be implemented to simultaneously carry out the optical sampling [8].…”

Data regeneration for an all‐photonic digital radio over fibre

“…The attenuated signal of power P ′ S (t) is fed to the reshaping block that consists of a hard limiter [10][11][12][13][14] and Gaussian filter blocks. At the hard limiter block, if the input sampled power is greater than a threshold value given by P th , the output power value of the hard limiter, P L (t), is 'one', otherwise it is 'zero' [15] …”

“…The resulting retimed optical pulses are amplified by an erbium doped fibre amplifier (EDFA), denoted by G3 in Fig. 4b, and fed into an optical power limiter [12][13][14], the output of which is fed to an optical Gaussian filter (OGF2) to perform the pulse reshaping process. In the simulated model, the splitter, Sp, is 50/50 and in time stretching block T d is about 1.4 ps, the length of fibre L1 is about 100 m. The attenuation of fibre L1 is about 0.2 dB/km.…”

Laser Sintonizável em Regime Mode-Locking Harmônico (HML) em Cavidade em Figura-de-Oito

“…O estudo de um laser a fibra óptica pode ser direcionado para geração de pulsos ultracurtos na qual a duração no tempo pode variar na faixa de femto e pico segundos. Recentemente, a taxa de repetição de pulsos em GHz de lasers mode-locking tem atraído muita atenção e pode ser utilizado para muitas aplicações, incluindo comunicações ópticas de altas taxas, metrologia e amostragem óptica (optical sampling) na digitalização fotônica de sinais de telecomunicações [1,2].…”