High-frequency electro-magnetic waves, including millimeter wave (mmWave) and terahertz, represent a frontier of research with transformative potentials in next-generation wireless communication, advanced sensing and imaging, and quantum science and applications. Leveraging strong nonlinear optical effects, photonic integrated circuits emerge as efficient approach for generating and manipulating electro-magnetic waves at high frequencies, offering advantages such as fast speeds, low signal loss, and excellent scalability. Thin-film lithium niobate (TFLN), with its low optical loss and high electro-optic coefficient, stands out as an exceptional photonic platform for both fundamental research and industrial applications [1].