Optical repeater with phase error correction

Claim 2

A phase modulated pulsed carrier wave transmission system for conveying binary information in the form of pulses such that the significance of each signal pulse is represented by the phase of the carrier within the envelope of that pulse measured with respect to a reference wave of the same frequency as that of the carrier, comprising: a optical source of a signal pulse train having synchronizing pulses Interspersed at regular intervals with information pulses, said synchronizing pulses all having the same phase; and at least one optical repeater for regenerating said pulse train further comprising: at least one self-quenching super-regenerative oscillator to perform high level clipping; and means for transforming a portion of the phase jitter of the incoming pulses into amplitude jitter which is then eliminated by said high level clipping.

Claim 3

A transmission system according to claim 1 wherein the frequency of the carrier wave is within the optical range of frequencies.

Claim 4

A transmission system according to claim 5 wherein said first, second and third high level clippers are provided by self-quenching super-regenerative oscillators.

Claim 5

A transmission system according to claim 3 wherein said repeater further comprises a feedback loop including: a first Fabry Perot etalon whose fundamental resonant frequency is equal to the synchronizing pulse repetition frequency such that part of the incoming pulse train is incident normally upon it whereby portions of the locally constituted frequency wave are caused to emanate from said first Fabry Perot etalon with a periodicity equal to the synchronizing pulse repetition frequency, a proportion of which is used as an auxiliary trigger for said oscillator; and a second Fabry Perot etalon whose resonant frequency is equal to the overall pulse repetition frequency arranged such that a proportion of the output of said first Fabry Perot etalon is incident normally upon it whereby a reference wave with a periodicity equal to the overall pulse repetition frequency of the system is produced.

Claim 6

A transmission system according to claim 2 wherein said repeater includes: a first high level clipper stage optically coupled to said optical source for removing amplitude jitter from the incoming signal; a first source of first and second locally constituted signals; first means optically coupled to said first high level clipper and to said first source for superimposing said first locally constituted signal on the output of said first high level clipper and converting the phase angle separation between unlike incoming signal pulses from an original value to pi /2; a second high level clipper optically coupled to said firs means for removing amplitude jitter resulting from phase jitter in the output of said first high level clipper; second means optically coupled to said first source and to said second high level clipper for superimposing said second locally constituted signal on the output of said second high level clipper and reversing the relative phase separation between unlike signal pulses; a third high level clipper optically coupled to said second means for removing amplitude jitter resulting from phase jitter in the output of said second high level clipper; a second source of a third locally constituted signal; and third means coupled to said third high level clipper and said second source for superimposing said third locally constituted signal on the output of said third high level clipper and restoring the phase angle separation between unlike signal pulses to the original non-reversed value.