WAVELENGTH MULTIPLEX COHERENT OPTICAL TRANSMISSION SYSTEM,申请号JP19890074248-传众专利搜索

WAVELENGTH MULTIPLEX COHERENT OPTICAL TRANSMISSION SYSTEM

申请公布号：JPH02252330(A)

申请号：JP19890074248

申请日期：1989.03.27

申请公布日期：1990.10.11

申请人：

NIPPON TELEGR & TELEPH CORP <NTT>

发明人：SUZUKI KAZUNOBU;NAKAZAWA MASATAKA;KIMURA YASURO

分类号：H04J14/00;H04B10/29;H04B10/299;H04B10/40;H04B10/50;H04B10/60;H04J14/02

主分类号：H04J14/00

摘要：PURPOSE:To miniaturize an amplification medium and to extend the transmission distance and capacity by inserting an optical amplifier made of a single mode optical fiber added with the rare-earth element Er excited by an output light of a semiconductor laser. CONSTITUTION:The output light of frequency stabilizing light sources 11a-17a becomes a wavelength multiplex signal light while being coupled through one optical fiber via optical modulators 21a-27a and a multiplexer 30a. Then the signal light is sent to a receiver side by a transmission optical fiber 31 and made incident into an Er added optical fiber amplifier 34 via a multiplexer 36. Then an output light of an Er fiber amplifier exciting light source 35 using a semiconductor laser having an oscillated wavelength in a range of 1.40-1.50mum is coupled via the multiplexer 36 and the light is stimulated and the amplifier 34 applies amplification operation. Then the amplified signal is inputted to coherent demodulation circuits 81a-87a via a demultiplexer 37a and photodetectors 71a-77a or the like and demodulated into an electric signal. Thus, the signals subject to wavelength multiplex are amplified in the lump, the transmission distance and the transmission capacity are expanded and the amplification medium is made small.