Thin film lithium niobate photonic integrated circuit for laser beam scanning imaging

A photonic integrated circuit (PIC) is required to combine the three basic colors of red, green, and blue laser beams into a single output laser beam to realize an ultra-compact full-color laser beam scanning (LBS) display. However, the conventional approach of controlling the color solely by altering the injection currents to the laser diodes constrains the speed required to achieve a high resolution and also results in high power consumption. In this study, we address this challenge by proposing an active PIC based on sputter‑deposited thin-film lithium niobate (TFLN) using Mach–Zehnder interferometers (MZIs) to control the intensity of the red, green, and blue colors by applying voltage to the TFLN-PIC. These three colors are combined into a single laser beam using a multiplexer-fabricated TFLN waveguide. A bandwidth of 10 GHz, which is wide enough to realize 4K resolution and higher, was experimentally confirmed. The TFLN active PIC successfully achieved full-color generation, demonstrating that the proposed approach can be used to obtain ultra‑compact, full‑color LBS displays.