| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that when input power is small, an error in calculation of a signal to noise ratio becomes large as a transmissive spectrum width of an optical multiplexer/demultiplexer becomes narrow and this causes difficulty in correct system design although when power of a non-modulation optical carrier to an optical amplifier is large, approximate calculation can be performed, in an optical wavelength multiplex transmission system for modulating an optical carrier after amplification. <P>SOLUTION: In an optical wavelength multiplex transmission system in which an optical amplifier is arranged in a prestage of an optical modulator, a naturally emitted component to be generated from the optical amplifier is used to calculate a signal to noise ratio. Thus, reception sensitivity and permissible loss can be correctly obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT |
