OPTICAL TRANSMISSION SYSTEM AND OPTICAL TRANSMITTER USED FOR IT

摘要

PROBLEM TO BE SOLVED: To provide an optical transmitter in which the number of subcarrier signals is increased without causing clipping or an optical modulation degree of each subcarrier signal is improved and to provide the optical transmission system using it. SOLUTION: Multipliers 112-11N are used to multiply element signals (g1 -gN) being sum signals of RF signals (e1 -eN) and DC signals (V1 -VN) to generate an accumulated signal hN. The accumulated signal hN is given to a semiconductor laser 120, in which the signal is converted into a light intensity modulation signal. Respective occupancy signals of N-sets of the RF signals (g1 -gN) are not overlapped with each other and not overlapped with harmonic frequencies produced by the multiplication of the RF signals. Thus, the number of the RF signals is increased without changing the optical modulation and clipping.