Abstract: An optical information-bearing signal is regenerated by branching a portion off that signal while the remaining portion permanently bypasses the regeneration. The branched-off portion is converted into an electrical signal which is processed to regenerate, at a higher power level, the information in a manner which is dynamically invariant to a wide range of input level changes. The regenerated signal is superimposed upon the passed-through signal. A three-signal level encoding scheme is employed and the regeneration involves referencing the branched-off portion electrically against two thresholds in a manner which maintains a constant amplitude relation between the thresholds and the arithmetic average of the electrical signal representing the branched-off portion. The regenerating units are used in series and designed so that two or more in a row can drop out and still the signal can be regenerated by the next operational regeneration.