Dielectric distributed Bragg reflectors: towards strong light-matter interactions

• Main Author: Dyah Ayu Nurun Nafisah
• Other Authors: Gao Weibo
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Science::Physics
• Online Access: https://hdl.handle.net/10356/163164
• Institution: Nanyang Technological University

In this report, we present the observations of strong exciton-polariton coupling in a semiconductor quantum microcavity structure. The first section will begin by introducing the mathematical tools used to generate the simulated theoretical transmission spectra via transfer matrix methods. The discussion will then be followed by the concepts of particle interactions which cover the notions of exciton and polariton in the microcavity. The section will be finished with the explanation on the structure and the frameworks of the semiconductor quantum microcavity as well as the principles of the techniques that were adopted in the experiments. The simulated transmission spectra reveal several parameters that can affect the stopband properties of the microcavity, such as refractive index contrast, a number of bi-layer pairs, the relative configuration between the top and the bottom DBRs, as well as the presence of additional layer in between the two DBRs. Experiments were done on both the empty microcavity and the microcavity involving the dielectric active region. While the experiment at room temperature did not succeed in observing the presence of strong exciton-polariton coupling, the experiment conducted at cryogenic temperature showed the presence of Rabi splitting in the energy dispersion which suggests the existence of strong coupling in the cavity structure. Upon the completion of this project, further study on the strong coupling will be conducted to uncover many other properties of the semiconductor quantum microcavity.