Silicon based quantum integrated photonics

Abstract

Quantum integrated photonics is an essential technology for implementing photon- based quantum technology, which will play a pivotal role in the development of quan- tum information science. Quantum information science, including quantum comput- ing and quantum communication, utilizes the advantageous properties of quantum mechanics to enable rapid information processing and high security, making it a next- generation technology. Photons possess unique advantages for realizing these tech- nologies, particularly as an irreplaceable basis for quantum communication. Integrated photonics has emerged as a crucial technology to harness the potential of photons. Its compact size, stability, scalability, and speed are highly beneficial for implementing complex quantum technologies. Silicon, known for its excellent elec- trical and optical properties, has significantly contributed to the advancement of quan- tum integrated photonics. Additionally, silicon can take advantage of well-developed semiconductor processing technologies and offers compatibility with complementary metal oxide semiconductor technologies. To implement quantum technologies, quantum photonic systems require components such as quantum light sources for generating quantum states, linear photonic circuits for manipulating these states, and detectors for analyzing the states. This thesis focuses on the research of quantum light sources and photonic circuits. In Chapter 1, we provide a review of the field of silicon-based quantum integrated photonics. In Chapter 2, we discuss the design and testing of integrated optical com- ponents necessary for quantum integrated photonics. In Chapter 3, we investigate the theoretical and experimental aspects of photon-pair generation in lossy waveguides to enhance performance. In Chapter 4, we propose the use of on-chip filters to sup- press external noise that may occur between external filters and waveguides in on-chip photon-pair sources. In Chapter 5, we demonstrate the 8×8 on-chip directionally un- biased multiport, a recently proposed structure that offers significant advantages for quantum simulations, using integrated photonics.