Lončar, MarkoXin, CJ2026-01-1320252025-05-192025Xin, CJ. 2025. On-chip generation and manipulation of quantum states of light in thin-film lithium niobate. Doctoral Dissertation, Harvard University Graduate School of Arts and Sciences.32041275https://dash.harvard.edu/handle/1/42725065Within the last decade, thin-film lithium niobate (TFLN) has emerged as a leading integrated photonics platform with immediate applications in classical communications. Concurrently, TFLN components tailored to the requirements of photonic quantum information processing have also garnered considerable interest. Chief among these is the quasi-phase matched (QPM) nonlinear frequency mixer—implemented via periodic domain inversion in ferroelectric lithium niobate—which can be used to generate photon pairs, squeezed states of light, and to perform single photon frequency conversion. Here, we demonstrate progress towards realizing a spectrally separable photon pair source in lithium niobate via waveguide dispersion engineering—a technique uniquely enabled by sub-wavelength optical mode confinement in the thin-film platform. Subsequently, we design optimize a scalable fabrication process to produce QPM TFLN devices for applications that require strict adherence to a specified operating wavelength, such as quantum frequency conversion in a quantum communications network. Finally, we explore how high-performance electro-optic devices can be combined with these nonlinear optical devices to realize a multi-functional platform in which quantum states of light can be generated and manipulated within a single, compact photonic integrated circuit.application/pdfenlithium niobatenolinear frequency conversionnonlinear opticsperiodically poled lithium niobatequantum opticsthin-film lithium niobateApplied physicsEngineeringOpticsThesis or Dissertation2026-01-130000-0002-9596-1407