A High Speed Comparator for Use in Optical Fibre Link Receivers

This paper describes the design methodology used to develop a high speed comparator for use in the regeneration of digital optical fibre communication systems. The comparator functions as a high gain amplifier block with excellent limiting characteristics and thus provides a compatible interface to the following E.C.L. decision gate. Accommodation of a large dynamic range of optical signal level eliminates the need for automatic gain control (a.g.c.) circuitry. Data rates up to 600 Megabits per second can be detected using the new device design.