Synchronous, asynchronous, data rate transparent fiber optic communications link

Abstract

An optical fiber communications link which by means of pulse-width-modulation (PWM) encoding supports either synchronous or asynchronous data transmission and operation over a wide range of data rates. The link utilizes a PWM encoder which accepts either synchronous (clock plus data) or asynchronous (data only) binary inputs and generates a PWM encoded waveform. This waveform is transmitted via an optical transmitter, optical channel (e.g., fiber optics) and optical receiver to the PWM decoder which reconstructs the binary inputs. The optical receiver contains a receiver circuit for assuring automatic gain control regardless of the duty cycle. In the synchronous mode of operation the unsymmetrical clock output is restored to symmetry by using a clock symmetry restoration technique.

Dependencies are inferred from the claim text.