Research Of Optical Phase Quantization Based On Phase Sensitive Amplifier

With the constant improvement of the level of informatization, the transmission pressure of optical communication system also increase. Using all-optical signal processing can avoid the photoelectric conversion, meeting the needs of high-speed signal processing. The functions of optical signal processing such as modulation, multiplexing , wavelength conversion and optical logic etc all have already been demonstrated, but there's lacking of optical phase quantization research. With the widely application of the phase modulation format signals, the problem of signal's phase ambiguity caused by the noise in transmission process needs to be resolved. Meanwhile, the erbium doped fiber amplifier in optical communication system will introduce the amplified spontaneous emission noise, which will lead to the degradation of the phase ambiguity signal. As an important part of all-optical signal processing, optical phase quantization based on phase sensitive amplifier can be applied to the optical signal amplitude and phase analog-digital conversion, it can also be used in the regeneration of the phase modulation signal. The paper focuses on the issue of optical signal quantization precision of phase quantification and taking further study on this point. Main work and research contents of the paper is as follows:1. The research foucuse on muti-wave interference to realize high precision optical phase quantization. Taking the in-depth analysis of the problems which existing in double-wave interference phase quantization method, such as the lower quantizationg accuracy, hard to control the power ratio of interfere waves. Based on this, multi-wave interferometric phase quantization method is proposed, with the introduction of high order harmonic to correct the quantified result of low harmonic, the higher accuracy quantization result can be reached. At the same time, the influence of phase quantization results caused by the phase,number and power ratio of the waves participating in interference are studied, and put forward a new method which separating the process of harmonics generation and interference to control the power ratio accurately and conveniently, in order to realize the higher accuracy of quantification. The paper has briefly analyzed the influence of the amplitude niose of the signal on quantizaiton accuracy, and improve the quantization accuracy by the signal's amplitude preprocessing.2. Multi-wave interference phase quantization is applied to the regeneration of phase modulation signal. Introducing the significance of regenerating phase modulation signal and using multi-wave interference phase quantization to regenerate QPSK signal. Compared with the current dual-wave interference regeneration results, the new method get better phase regeneration results, more flat phase transition curve and lower phase variance.