All-optical AND and NAND gates based on cascaded second-order nonlinear processes in a Ti-diffused periodically poled LiNbO3 waveguide

Abstract

All-optical AND and NAND gates have been demonstrated in a Ti-diffused periodically poled LiNbO(3) channel waveguide which has two second-harmonic phase-matching peaks by cascaded sum-frequency-generation/difference-frequency-generation (cSFG/DFG) and sum-frequency-generation (SFG) processes. The conversion efficiency of signal to idler (AND gate signal) was approximately 0 dB in cSFG/DFG process. In the second SFG process, more than 15 dB extinction ratio between signal and dropped signal (NAND gate signal) has been observed.

Quasi-phase matched optical frequency comb generation through cascaded second order nonlinearity in a micro-ring resonator

“…According to Eqs. (6)(7)(8) and the related discussions, as long as Δ = m + n -p ≠ 0. the involved WGMs (m, n and p) always could be quasi-phase-matched given a suitable domain inverted open angle θ. For an odd Δ, θ = π, while for a even Δ = 2 n ×odd, θ = π/2 n .…”

“…Up to date, QPM optical switching [8], single photon detection [9] and nonlinear plasmonic or metamaterial frequency conversion [10,11] have been proposed or demonstrated from continuous wave to femtosecond pulsed lights [12]. It should be very attractive to further explore the QPM in optical frequency comb generation.…”

Simulation and Demonstration of Directed XOR/XNOR Logic Gates Using Two Cascaded Microring Resonators

“…In recent years, various optical directed logic circuits have been proposed and demonstrated, such as OR/NOR gate [19], AND/NAND gate [20], [21], etc. XOR/XNOR logic operations are indispensable in encoding and decoding schemes, parity checking, and data encryption/decryption, which has been attracted widespread attention in past years [22]- [25].…”

Interaction-free all-optical switching via the quantum Zeno effect

“…A necessary resource for such networks is all-optical switching, in which the state of a signal wave is switched in the presence of a control wave (pump). This is routinely achieved using direct coupling between the two waves in nonlinear materials, such as semiconductors [1], χ (3) fibers [2][3][4][5], and cascaded χ (2) waveguides [6][7][8][9][10]. A fundamental limit in these devices is due to the photon loss resulting from signal-pump coupling.…”