Nonlinear Coherent Light–Matter Interaction in 2D MoSe₂ Nanoflakes for All‐Optical Switching and Logic Applications

Abstract

A strong nonlinear optical response of 2D MoSe2 nanoflakes (NFs) through spatial self‐phase modulation (SSPM) and cross‐phase modulation (XPM) induced by nonlocal coherent light–matter interactions is reported. The coherent interaction of light and MoSe2 NFs creates the SSPM of laser beams, forming concentric diffraction rings. The nonlinear refractive index (n2) and third‐order broadband nonlinear optical susceptibility (χ(3)) of MoSe2 NFs are determined from the self‐diffraction pattern at different exciting wavelengths of 405, 532, and 671 nm with varying laser intensity. The evolution and deformation of diffraction ring patterns are observed and analyzed by the “wind‐chime” model and thermal effect. By taking advantage of the reverse saturated absorption of 2D SnS2 NFs compared to MoSe2, an all‐optical diode has been designed with MoSe2/SnS2 hybrid structure to demonstrate the nonreciprocal light propagation. Few other optical devices based on MoSe2 and semiconducting materials such as Bi2Se3, CuPc, and graphene have been investigated. The all‐optical logic gates and all‐optical information conversion have been demonstrated through the XPM technique using two laser beams. The proposed optical scheme based on MoSe2 NFs has been demonstrated as a potential candidate for all‐optical nonlinear photonic devices such as all‐optical diodes and all‐optical switches.

Degenerate and non-degenerate all-optical switches using violet phosphorus nanosheets

“…The obtained τ F value is inversely proportional to the light intensity I, which is consistent with the observations reported previously. 16,21,28 The measured τ F value of VP Ns is slightly shorter than the τ F of ∼0.7 s of BP Ns. 9 It is known to all that the nonlinear refractive index n 2 of the material can be directly inferred from the intensity dependence of the ring number in the complete ring pattern.…”

“…The obtained τ F value is inversely proportional to the light intensity I , which is consistent with the observations reported previously. 16,21,28 The measured τ F value of VP Ns is slightly shorter than the τ F of ∼0.7 s of BP Ns. 9…”

“…13,14 In the past decade, the SSPM effect has been observed in atomically thin two-dimensional (2D) nanomaterials, such as graphene, 15 transition metal dichalcogenides, 16 topological insulators, 17 and other types of nanomaterials. 9 Meanwhile, researchers have developed a variety of nonlinear photonic devices based on the superior coherence electronic nonlinearity of 2D nanomaterials, such as all-optical switches, 16 all-optical diodes, 18 all-optical information converters, 19 logic gates, 20,21 and nonlinear isolators. 22 In these applications of nonlinear photonic devices, all-optical switching performance is undoubtedly the most widely demonstrated.…”

Strong non-linear optical response of Sb2Se3 nanorods in a liquid suspension based on spatial self-phase modulation and their all-optical photonic device applications

“…From the following equation, L eff of the laser beam can be determined: 41,42 where z 0 = π ω 2 0 / λ , with ω 0 = 1/ e 2 being the beam radius; L 1 , L 2 are the distances from the focus ( f ) to the side of the quartz cuvette; and z 0 is the diffraction length. Therefore, the nonlinear refractive index of Sb 2 Se 3 can be determined from the formula 31 …”

“…Subsequently, the third order nonlinear susceptibility χ (3) total of Sb 2 Se 3 can be determined by 29,31 where c is the velocity of light in free space. As Sb 2 Se 3 is a layered material, the nonlinear susceptibility of a single layer has a significant role and can be determined by 29,31 χ (3) total = χ (3) singlelayer × N 2 eff …”