Electrical control of second-harmonic generation in a WSe2 monolayer transistor

Abstract

Nonlinear optical frequency conversion, in which optical fields interact with a nonlinear medium to produce new field frequencies 1 , is ubiquitous in modern photonic systems.However, the nonlinear electric susceptibilities that give rise to such phenomena are often challenging to tune in a given material, and so far, dynamical control of optical nonlinearities remains confined to research labs as a spectroscopic tool 2 . Here, we report a mechanism to electrically control second-order optical nonlinearities in monolayer WSe2, an atomically thin semiconductor. We show that the intensity of second-harmonic generation at the A-

Gate‐Tunable Resonant Raman Spectroscopy of Bilayer MoS2

“…[5,6] Such manipulation of physical properties through electrical control is important to deepen the understanding of the physics behind each phenomenon. Moreover, realization of possible new applications also benefits from the development of gate control, such as in the observation of gate-tunable memristive device.…”

Quantum localization issues in nonlinear frequency conversion and harmonic generation

“…[6][7][8] Another application of optical harmonic generation involves utilizing SHG as an optical probe to characterize interfaces and surface dynamics. [9][10] Contemporary work in the field has centred upon creating next-generation SHG materials 11 that exhibit significantly enhanced generation of optical harmonics using semiconductor metamaterials 12 , exciton-enhancment 13 , and atomic crystals 14 . The process of SPDC is the time reversal of SHG (see Fig.…”

Second harmonic generation in nanoscale films of transition metal dichalcogenide: Accounting for multipath interference

“…[8][9][10][11][12] Unlike graphene, two-dimensional (2D) TMDs are semiconductors with the band gap that can be tuned by changing the number of atomic layers in a slab. For technological reasons one of the best substrates for these structures is an oxidized silicon wafer.…”

“…9,17,18 SHG is used for determination of crystallographic orientation of the flakes or microcrystallites in deposited TMD films. [19][20][21] In many studies, significant enhancement of SHG is reported in nanoscale TMD layers compared to the bulk TMD crystals.…”

“…This phenomenon is of fundamental interest. 9 Generally, the reported values of nonlinear susceptibility of TMD nanoscale layers have big dispersion. 22,23 In this paper, we develop the transfer matrix technique to calculate intensity of the SH wave generated in TMD (based on work of Li 5 ).…”