Abstract

An ideal cw laser operates in a single mode at a well defined frequency. Real lasers often have many modes at slightly different frequencies. Mode competition associated with nonlinear processes can temporarily suppress all but one of these modes, while fluctuations can cause the laser to “hop" to a new frequency. This problem is particularly severe in diode lasers, where it is difficult to completely suppress unwanted modes. The resulting mode-partition noise degrades the performance of communication systems.¹ A description of the electric-field correlation function and power spectral density would help in both understanding existing systems and designing new systems.

© 1994 IEEE