Enhanced second-harmonic generation in strained germanium-on-insulator microdisks for integrated quantum photonic technologies

• DOI: 10.1364/ol.497741
• Publication Date: 2023-07-24T18:00:09Z
• Authors: James Tan; Xuncheng Shi; Kunze Lu; Hyo-Jun Joo; Youngmin Kim; Melvina Chen; Lin Zhang; Chuan Seng Tan; Khee Yong Lim; Elgin Quek; Donguk Nam
• Keywords: Engineering::Electrical and electronic engineering; Second-Harmonic Generation; :Electrical and electronic engineering [Engineering]; 7. Clean energy; 530; Quantum Photonic; 620

Quantum photonic circuits have recently attracted much attention owing to the potential achieve exceptional performance improvements over conventional classical electronic circuits. Second-order χ(2) nonlinear processes play an important role in realization of several key quantum components. However, their centrosymmetric nature, CMOS-compatible materials including silicon (Si) and germanium (Ge) traditionally do not possess response. Recently, second-harmonic generation (SHG) that requires response was reported Ge, but no attempts at enhancing SHG signal been conducted proven experimentally. Herein, we demonstrate effect strain on from Ge by depositing a nitride (Si3N4) stressor layer Ge-on-insulator (GOI) microdisks. This approach allows deformation unit cell structure which can further enhance susceptibility for emission. The experimental observation under femtosecond optical pumping indicates clear trend enhancement signals with increasing strain. Such boost conversion efficiencies 300% when compared control counterpart. technique paves way toward realizing material characteristics, presenting unforeseen opportunities its integration semiconductor industry.