Thin film lithium niobate for integrated oscillator and entangled photons (Invited Paper)

Thin film lithium niobate (TFLN) has emerged as a leading platform for integrated photonics, combining frequency conversion with low-loss waveguides and electro-optic effects. These properties help to address key limitations of silicon-based material platforms, which rely on third-order processes and suffer from nonlinear photon absorption. While TFLN has proven effective in classical devices, its potential for scalable quantum photonic circuits remains marginal. Here, I will present a low threshold integrated optical parametric oscillator with a compact Bragg resonator. Then, I will show different type of periodic poling on chip for spontaneous parametric down conversion such as counter or back propagation convenient for high generation efficiency, single polarisation and high purity of photons.