Compact hybrid silicon nitride and lithium niobate nano-film photoelectronic reversible logic gate

Photoelectronic hybrid logic operation improves digit circuit efficiency without any additional photoelectric conversion, especially a photoelectronic reversible logic gate may reduce energy dissipation. In this paper, a compact photoelectronic reversible logic gate is proposed based on a hybrid silicon nitride and lithium niobate nano-film waveguide. Tow Mach-Zehnder modulators are cascaded together to construct the main part of the compact photoelectronic reversible logic gate. The whole length of the gate is only 4.4 mm, one hundredth of the length of the common proton exchange lithium niobate modulator. By operating at the wavelength of 1.55 mu m, the proposed Mach-Zehnder modulator only requires 4.9 V voltage to complete a full cross-coupling, which is well compatible with CMOS technology. It is demonstrated that at the wavelength range of 1.4 mu m to 1.6 mu m, the average insertion loss is 0.6 dB, the minimum crosstalk is -47 dB, and the maximum extinction ratio is 41 dB; in the voltage range of 4 V to 6 V, the average insertion loss is 0.63 dB, the minimum crosstalk is -26 dB, and the maximum extinction ratio is 22 dB. These features indicate that the photoelectronic reversible logic gates have good performances, bringing the photoelectronic logic gates into a new design parameter space and providing a possible solution for easing the electronic bottleneck.