The linewidth of semiconductor lasers is one of the most important factors determining the performance of a coherent optical fiber communication system. The stringent linewidth requirement, typically 10−10 of the optical frequency, is a major obstacle in coherent optical fiber communication use. This study is concerned with relaxing the linewidth requirement by coding. The phase-shift-keying (PSK) heterodyne demodulation scheme with convolutional codes is used to illustrate the results.
© 1988 Optical Society of AmericaPDF Article