The Key Techniques Of FSK And Its Application In The OLS

With the rapid development of high-speed, large-capacity, high-spectral-efficiency optical communication system, the nonlinear effect in optical fiber become the fatal factor of restricting bandwidth and transmission distance of optical communication system increasing, the traditional method of modulation system cannot meet the higher requirements. With the advantages of high receiver sensitivity ,high nonlinear tolerance ,easy demodulating and its application in optical label switching that joining or extracting label information in the Carrier without affecting light intensity and other aspects of performance, Frequency Shift Keying (FSK) has become the hotspot in the large-capacity and long-haul optical communication technologies.Under the support of the Program for National Natural Science Fund Projects,863 and New Century Excellent Talents in University of Ministry of Education,the key techniques and its application in Optical Label Switching(OLS) of FSK is investigated theoretically and experimentally. The studies are carried out as the followings:(1) Analysis of the key techniques of FSKThe key techniques of FSK is discussed, we propose and demonstrate a novel scheme of high bit rate FSK transmitter, elaborate its implementation principle. Besides we analysis the influences of optical filter for FSK signal demodulation using VPI simulation tools, Simulation results show Gaussian filter whose bandwidth is 80GHz and the Gaussian order is 10 or higher has the best performance for demodulation.(2) Analysis of transmission characteristic of FSK and its application in Optical Label SwitchingWe use the high bite rate FSK transmitter mentioned above to simulate the receiver power penalty in different power, different dispersion compensation schemes (previous compensation, post compensation, hybrid compensation) after 80 km Single Mode Fiber (SMF) fiber links transmission. Besides the dispersion tolerance and frequency tolerance are analyzed. The simulation results show that there is best transmission characteristic when we induce the post dispersion compensation scheme, and the dispersion tolerance is 95ps/nm under 1 dB power penalty. The application in OLS of high bite FSK signal is verified experimentally and simulation. The influence of extinction ratio for the transmission characteristic is simulator investigated. Besides we experimentally demonstrate, a 100 km SMF transmission link with matching dispersion compensation module of a 40 Gb/s RZ-FSK signal with 2 dB penalty. Transparent wavelength conversion is achieved as well based on four-wave mixing in a Semiconductor Optical Amplifier (SOA), We experimentally demonstrate, to our knowledge for the first time, an ASK labeled 10Gbit/s FSK signal transmission over 85 km SMF transmission link with matching dispersion compensation module. The theory of high FSK signal applied to Optical Label Switching (OLS) is further improved.