A New Scheme to Implement the Reconfigurable Optical Logic Gate in Millimeter Wave Over Fiber System

In this work, we employ two Mach-Zehnder modulators (MZM) to achieve a novel six kinds of reconfigurable optical logic gate in millimeter wave over fiber, in which one MZM is used to generate millimeter wave (mm-wave) signal and the other is used to attain optical logic gate. By adjusting the direct current (DC) bias voltage of the first MZM, a frequency doubling mm-wave signal can be obtained and no filter is needed. By controlling the radio frequency (RF) drive voltage and DC bias voltage of the second MZM, the phase of between upper and lower arms can be converted. By adjusting the phase of the first channel RF signal to
$(\pi /2,0)$
, setting the phase of the second channel RF signal to
$(0,\pi /2)$
and controlling the bias voltage to let the phase of the upper and lower to be
$\pi /2$
and
$\pi /4$
, respectively, OR logic gate can be obtained. To obtain AND, NOR, NAND, XOR and NXOR logic gate, we just need to get proper phase by adjusting the RF drive voltage and DC bias voltage of the second MZM. According to the simulation, the millimeter wave signal with a frequency of 50 GHz can be obtained, which has completed the logic operation.