| Summary: | 博士 === 元智大學 === 電機工程學系 === 90 === In this dissertation, we proposed and demonstrated four fiber optical CATV systems. First, we proposed a fiber to the home (FTTH) - broadband integrated services system by using Fabry-Perot (FP) laser diode, switched-star network architecture, one channel transmission, 1310/1550 nm wavelength-division-multiplexing (WDM) and bi-directional interactive transmission techniques. This proposed system simultaneously provides CATV, cable FM, and high-speed data line services over the single-mode fiber (SMF) at the subscriber. We successfully developed the more economic system, which makes the interactive broadband multimedia services more feasible in the future.
Second, we proposed and demonstrated a bi-directional interactive fiber optical CATV addressable system. It uses the relative-poor linearity of FP laser diode, WDM and CATV addressable techniques. The measured values of carrier-to-noise ratio (CNR), composite second order (CSO) and composite triple beat (CTB) can satisfy the fiber optical CATV system requirements in our proposed system. This proposed bi-directional communication system is new, simple, economic and suitable for fiber optical CATV architecture.
Third, we presented a directly modulated NTSC AM-VSB 74-channel bi-directional fiber optical CATV long-distance (over 110 km) transmission system in the 1550 nm region, which used high power 1550 nm digital distributed feedback (DFB) laser diode (20 mW), in-line erbium-doped fiber amplifiers (EDFAs), one channel transmission and superheterodyne techniques. Good CNR of 50 dB, CSO of 70 dB and CTB of 64 dB were obtained after 110 km of standard SMF transmission.
Finally, we presented a directly modulated 1550 nm NTSC AM-VSB 77-channel fiber optical CATV long-distance transport system using push-pull preamplifier and large effective area fiber (LEAF). Good performances of CNR 50 dB, CSO 62 dB and CTB 61 dB were obtained over a 100 km LEAF transport. Compared with a conventional externally modulated system, our proposed system does not require expensive externally modulated transmitter, sophisticated stimulated Brillouin scattering (SBS)-suppression and differential detection techniques, as well as CTB-predistortion circuit. This proposed directly modulated transport system is simpler and more cost-effective than the conventional externally modulated transport system.
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