Abstract

In future multichannel optical networks equipped with high density wavelength division multiplex (HDWDM) or coherent systems the fluctuations of the transmitter laser frequencies must be small compared with channel spacing in the range of a few Gigahertz. Several frequency control techniques have been demonstrated to get an absolute and relative frequency stability [1],[2],[3]. In switched multichannel broadband communication systems additional expensive equipment is necessary to control all locally dispersed independent subscriber lasers. As an alternative in future it might be possible that the center frequency of a free-running laser diode is stable enough and no additional frequency control or only a simple control mechanism must be employed.

© 1993 Optical Society of America