A Study Of Optical Packet Compressor Based On SOA's Switching Characteristics

Optical packet compress is a key technology in OTDM packet multiplexer. In this paper, an optical packet compressor scheme based on the switching characteristics of semiconductor optical amplifier (SOA) is demonstrated.By applying the multi-section model from the SOA's carrier rate equation and the optical power propagation equation derived from the optical packet compressor proposed in this paper. The changes of the peak chirp, the output extinction ratio and the ratio of full-width at half-maximum (FWHM) with the peak power and the wavelength of the input pulse are investigated at each stage compressor. The results show that the peak chirp of the output pulse improves when the peak power of the input pulse increases. it is extremely obvious at the first stage; the peak output chirp appears in parabola when the wavelength of the input pulse increases, and reach max at the wavelength of the peak gain. the ratio of FWHM and the output extinction ratio appear improve and degradation respectively when the peak input power increases; the output extinction ratio degrades mostly at the wavelength of the peak gain. Moreover, the ratio of FWHM and the output extinction ratio at different driving currents of the SOA are also analyzed. The results show that the ratio of FWHM and the output extinction ratio appear improve and degradation respectively when the driving current increases.The reduction of the pattern dependence associated with the adjacent pulses is achieved and consequently compression efficiency of the compressor is improved by adding continuous-wave holding signal or decreasing the driving current both scheme can reduce carrier recovery time. the advantages and disadvantages of two scheme are discussed.Detailed study is made on the SOA's switching effect under two conditions, pre-turn on switch only and pre-turn on and off simultaneously; At the second scheme, the compression efficiency affected by the times in which switch pre-turn on at the third stage compressor is investigated ; at the same time , the compression efficiency affected by the input signal rate is analyzed, point out that the compression efficiency is becoming deteriorated when signal rate increases.