OPTICAL TRANSCEIVER FOR GENERATING DUOBINARY CSRZ AND CSRZ-DPSK OPTICAL SIGNALS HAVING STRONG DISPERSION CHARACTERISTIC IN OPTICAL COMMUNICATION SYSTEM

摘要

PURPOSE: An optical transceiver for generating duobinary CSRZ(Carrier Suppressed Return-to-Zero) and CSRZ-DPSK(Differential Phase Shift Keying) optical signals having a strong dispersion characteristic in an optical communication system is provided to generate duobinary CSRZ optical signals and CSRZ-DPSK optical signals using a data encoder, an external modulator, and an electrical mixer and to diminish the optical spectrum bandwidth of an optical signal using the band-limiting of a low band pass filter. CONSTITUTION: An optical transceiver for generating duobinary CSRZ optical signals and CSRZ-DPSK optical signals is comprised of a data encoder(300), an electrical mixer(302), a low band pass filter(304), an amplitude adjuster(306), and an external Mach-Zehnder modulator(308). The data encoder(300) modulates an inputted binary data signal. The mixer(302) mixes two RF signals in an electrical signal domain. The low band pass filter(304) passes a low frequency band only. The amplitude adjuster(306) adjusts an RF input signal. The external Mach-Zehnder modulator(308) modulates an optical signal, inputted from an external luminous source, according to an inputted RF signal.