Within the last half-decade, thin-film lithium niobate (TFLN) has emerged as an integrated photonics platform with immediate applications in classical telecommunications. Concurrently, there has also been a proliferation of TFLN components developed for applications in quantum information technologies. Chief among these is the quasi-phase matched nonlinear frequency mixer, which can be used to generate photon pairs, squeezed states of light, and to perform single photon frequency up-/down-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 the strong confinement of light in nanophotonic waveguides. Subsequently, we study and optimize the fabrication of process flows for the scalable production and integration of devices for generating biphoton states with more complex engineered joint spectra, and for quantum frequency conversion in applications with stringent operating wavelength requirements.
an example publication: Single-photon frequency shifting using coupled microring resonators on thin-film lithium niobate