Patent ID: 8000605

Claim:
A method of combining N input NRZ optical data signals, each having an equal bit period and duty cycle, into one time-division multiplexed output signal, comprising: providing N synchronized input NRZ signals; shortening the pulse width of each input signal by reducing the duty cycle by a factor of 1/N while keeping the bit period the same; delaying said shortened input signals one from another by a fixed delay such that all N signals occur within one said bit period; and combining said delayed N shortened signals to form one multiplexed output signal, wherein N is an integer greater than 1 and is equal to the number of signals being combined; and wherein said shortening of the pulse width while keeping the bit period the same comprises: AND-ing the input signal with a gap clock signal, where said gap clock signal has a pulse width equal to 1/N of the bit period of the input signal, and a bit period equal to that of the input signal.