Patent ID: 7558486

Claim:
An all-optical signal processing method comprising: delaying a first on-off-keying (OOK) signal by a delay that is substantially the same as a pulse width of the first OOK signal to generate a delayed first signal; delaying a second OOK signal by a delay that is substantially the same as a pulse width of the second OOK signal to generate a delayed second signal, wherein the first and second OOK signals are complementary is an inverse of the first signal so that when the first OOK signal is in a first state, the second OOK signal is in a second state and when the first OOK signal is in the second state, the second OOK signal is in the first state; modulating with a first nonlinear element a periodic optical signal with the first OOK signal when the first OOK signal is in the first state and with the delayed second signal when the first OOK signal is in the second state to generate a first modulated signal; modulating with a second nonlinear element the periodic optical signal with the second OOK signal when the first OOK signal is in the second state and with the delayed first signal when the first OOK signal is in the first state to generate a second modulated signal; phase shifting the second modulated signal π radians relative to the first modulated signal; and combining the first and second modulated signals to generate a-n a phase-shift-keying (PSK) output signal.