Investigation Of All-Optical Decision Based On Fiber Optic Parametric Amplification

In the high-speed long haul optical networks, the problem of the signal deterioration during the transmission must be solved. All-optical 3R regeneration, as is able to overcome the defects of electronic regeneration method, is an effective technology to eusure the transmission quality of the all-optical network (AON). All-optical decision is one of the key techniques to the realization of all-optical 3R regeneration. All-optical decision technique based on fiber optic parametric amplification (FOPA), with the ultrafast response and the abililty of processing multi-wavelength parallel signals at the same time, is considered as an important breakthrough point of multi-wavelength 3R regeneration. In this thesis, all-optical decision technique based on fiber optic parametric amplification is investigated, one novel method of multi-wavelength all-optical decision is also proposed.Based on the establishment of the theoretical models for the FOPA, the gain characteristics and input and output characteristics of the FOPA is analyzed. The optical switching characteristics of the FOPA using the intensity modulated clock pump is investigated, and a dual-channel 10Gb/s all optical modulation format conversion is demostrated experimentally to verify its performance.Single wavelength 10Gb/s all-optical decision based on the FOPA using the intensity modulated clock pump is investigated experimentally. The performance of the all-optical decision system is evaluated in detail through three parts of the input deteriorated signal including the wavelength, the transmission distance before regeneration and the signal to noise ratio (SNR). The results show that the Input signal quality is able to be improved after the all-optical decision as long as the input signal wavelength is within the range of 4nm from the pump wavelength; the input signal which is deteriorated by even 50km transmission can also be regenerated; a SNR enhancement of at least 8 dB can be obtained when the SNR of input signal is within 3-10dB.A novel scheme of multi-wavelength all-optical decision based on FOPA is proposed in order to reduce the interactions among the channels during the multi-wavelength 3R regeneration. The phase modulated clock pump instead of the intensity modulated clock pump is used in the FOPA to suppress interaction of different channels caused by the Kerr effects like cross-phase modulation (XPM). Meanwhile, the polarization state of the adjacent-channels are set to be orthogonal to further reduce four-wave mixing (FWM) effect among the channels. Asynchronous dual-wavelength 10Gb/s all-optical decision is demonstrated experimentally, and the SNR of the input signal that is deterioted through 30km transmission is successfully improved by 3-5dB after regeneration.