Abstract

The relatively simple concept of analog transmission systems makes them attractive for applications such as fibre-optic distribution of CATV signals and fibre-optic links between central and base stations for wireless telephony. Directly modulated DFB laser diodes are the preferred transmitters for such systems, but the analog character requires a very high linearity of the electro-optic conversion. While the specific requirements depend on the system implementation, CATV systems generally require a small 2nd and 3rd order distortion in a frequency band from 50 MHz to 1.8 GHz. Fibre-optic links for wireless communication on the other hand have the information concentrated in a small bandwidth around e.g. 1.9 GHz and therefore only require a small 3rd order distortion in that band. A 'small' distortion means over 60 dB below the carrier.

© 1996 IEEE