Patent ID: 8055137
Filing Date: 2011-11-08
Classification: H04B

Abstract:
1. A method for producing a phase coded non-return-to-zero (PC-NRZ) optical signal, the method comprising: providing an input optical signal; providing first and second drive signals, said first drive signal having a first data pattern of first and second signal levels, said second drive signal having a second data pattern, said second data pattern having third and fourth signal levels that toggle at least when said first drive signal changes from said first signal level to said second signal level; and modulating amplitude of said input optical signal with said first drive signal and modulating phase of said input optical signal with said second drive signal to produce said PC-NRZ optical signal, wherein said providing first and second drive signals comprises: applying a digital data signal to a data input port of a first digital flip-flop and thus producing said first drive signal at a normal output port of said first digital flip-flop; and applying an inverted output from said first digital flip-flop to a clock input port of a second digital flip-flop and thus producing said second drive signal at a normal output port of said second digital flip-flop, wherein an inverted output port of said second digital flip-flop is connected to a data input port of said second digital flip-flop.