Correlation of quantum well periods on the 3rd order nonlinear optical responses of InGaN/GaN heterostructures

Semiconductor multi quantum well (MQW) design allows for the compression of electron-interaction dimensions, offering advantages for various applications, particularly in nonlinear optics. Despite the potential improvements in nonlinear optical responses, the influence of quantum well periods remains unexplored. In this study, we report the correlation of quantum well periods on the 3rd order nonlinear optical properties in In0.15 Ga0.85 N/GaN MQW using z-scan technique under femtosecond and continous wave laser regime. In0.15 Ga0.85 N well/GaN barrier with x1, x5, x10, x15 periods were grown by MOCVD technique. Good structural quality of grown MQWs were confirmed via HRTEM imaging, EDS, AFM and XRD. Absorption coefficient from UV-Vis coupled with PL emission spectrum shows systematic response of optical linear properties which provide an insight on the overall band gap structure. Positive nonlinear refraction, n2 and nonlinear absoprtion, β trends is observed under femtosecond an CW laser albeit differences of one order magnitude in χ3 value. The increase in χ3 value is shown to be monotonous with the increasing number of quantum well suggesting that compounding effect took place. This findings indicate the possibility of manipulating and tuning nonlinear reponses of MQW structures leading to improvement in semiconductor design in various areas such as optoelectronics, photonics, solar cell research, as well as quantum information processing. •InGaN/GaN MQWs with different periods (x1, x5, x10, x15) were successfully grown by MOCVD, confirmed by HRTEM and EDS.•AFM reveals surface roughness between 10 to 36 nm, while XRD indicates layer thicknesses of 9 nm for GaN and 3 nm for InGaN.•UV-Vis spectroscopy shows minimum absorption, and photoluminescence analysis reveals band edge emssion at 465 nm.•χ(3) values are measured to be in the order of 10−6 esu and 10−5 esu for femtosecond and CW regime, respectively.•χ(3) values increase linearly with quantum well periods, indicating greater nonlinear optical responses in structures with more quantum wells.