Ultracompact all-optical logic gates based on nonlinear plasmonic nanocavities

Abstract

Abstract:In this study, nanoscale integrated all-optical XNOR, XOR, and NAND logic gates were realized based on all-optical tunable on-chip plasmon-induced transparency in plasmonic circuits. A large nonlinear enhancement was achieved with an organic composite cover layer based on the resonant excitation-enhancing nonlinearity effect, slow light effect, and field confinement effect provided by the plasmonic nanocavity mode, which ensured a low excitation power of 200 μW that is three orders of magnitude lower than the values in previous reports. A feature size below 600 nm was achieved, which is a one order of magnitude lower compared to previous reports. The contrast ratio between the output logic states "1" and "0" reached 29 dB, which is among the highest values reported to date. Our results not only provide an onchip platform for the study of nonlinear and quantum optics but also open up the possibility for the realization of nanophotonic processing chips based on nonlinear plasmonics.

Ultracompact all-optical full-adder and half-adder based on nonlinear plasmonic nanocavities

“…These means that when three logic signals "1" do full-addition operation, the Sum bit "1" and Carry bit "1" were obtained. Therefore, excellent logic operations of full-adder were achieved with an ultralow operating threshold intensity of 7.8 MW/cm 2 , which is reduced by two orders of magnitude compared with previous reports [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. The feature size of this function device is determined to be <15 μm, which is reduced by three orders of magnitude compared with previously reported results [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

“…A large third-order optical nonlinearity was obtained for the multicomponent nanoAu:(IR140:MEH-PPV) cover layer on account of tremendous nonlinearity enhancement related to resonant excitation, slow-light effect, and field enhancement effect provided by plasmonic nanocavity modes, which cause an ultralow operating threshold power of 300 μW (corresponding to a threshold operating intensity of 7.8 MW/cm 2 ), reduced by two orders of magnitude compared with previous reports [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. The total size of this function device is determined to be lower than 15 μm, which is reduced by three orders of magnitude compared with previously reported results [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. The intensity contrast ratio between the two output logic states "1" and "0" was larger than 27 dB, which is among the highest values reported to date [20][21][22][23][24]…”

Unidirectional reflectionless light propagation at exceptional points

“…Tuning the geometry rather than the refractive index can reduce the difficulty in the experimental realization of such structures. Among different plasmonic waveguide structures, MDM plasmonic waveguides are of particular interest [108][109][110][111][112][113][114][115][116], because they support modes with deep subwavelength scale over a very wide range of frequencies extending from DC to visible [117] and are relatively easy to fabricate [118,119]. The waveguide widths w, w 1 , and w 2 are set to be 50, 20, and 100 nm, respectively ( Figure 9A).…”

Ultracompact on-chip photothermal power monitor based on silicon hybrid plasmonic waveguides

“…The silicon HPWG, which usually has a metal strip, a silicon core, and an silicon oxide (SiO 2 ) insulator layer between them, was proposed as a novel waveguide with nanoscale light confinement as well as relatively long propagation distance [46] and has become very popular for integrated nanophotonics in the past years [60][61][62][63][64][65]. Meanwhile, plasmonic structures and waveguides are also promising candidates for the application at mid-IR wavelength [66,67].…”