High-speed pulse train amplification in semiconductor optical amplifiers with optimized bias current

Abstract

In this paper we have experimentally investigated the optimized bias current of semiconductor optical amplifiers (SOAs) in order to achieve the high-speed input pulse train amplification with high gain and low distortion. Variations of the amplified output pulse duration with the amplifier bias currents have been analyzed and it is found that compared with the input pulse duration, the amplified output pulse duration is broadened; as the SOA bias current decreases from the high level (larger than the saturated bias current) to the low level, the broadened pulse duration of the amplified output pulse initially decreases slowly and then rapidly. Based on the analysis, an optimized bias current of SOA for high-speed pulse train amplification is introduced. The relations between the SOA optimized bias current and the parameters of the input pulse train (pulse duration, power and repetition rate) are experimentally studied. It is found that the larger input pulse duration, the lower input pulse power or the higher repetition rate can lead to a larger SOA optimized bias current, which corresponds to a larger optimized SOA gain. The effects of assist light injection and different amplifier temperatures on the SOA optimized bias current are studied and it is found that assist light injection can effectively increase the SOA optimized bias current while SOA has the lower optimized bias current at the temperature 20°C than that at other temperatures.

Investigation of 2D-WH/TS OCDMA Code Stability in Systems with SOA-Based Device

“…The severity of gain recovery time on 2D-WH/TS OCDMA systems using SOAs is evident even at low data rates [10]. This is because of the nature of the code carriers' time-spreading.…”

Characteristics of ultrafast response induced by impulsive interference of excitons in a GaAs/AlAs multiple quantum well on a slightly strained buffer layer

“…The incompatibility between the strong optical nonlinearity and the ultrafast carrier/ exciton lifetime has been an important topic, and numerous types of investigations have been carried out to overcome it. For example, switching based on intraband carrier dynamics, 1,2) gain dynamics, 3,4) detuned Rabi splitting, 5) twophoton absorption, 6) photonic crystals, [7][8][9] metamaterials, 10) and the plasmonic effect [11][12][13][14] can be used to reduce the response time.…”