Compact Two‐Dimensional Focal‐Plane‐Array Beam Steering on Thin‐Film Lithium Tantalate Enabled by Binary Electrode Coding

ABSTRACT Two‐dimensional (2D) solid‐state optical beam‐steering systems are highly desirable for next‐generation light sensing and free‐space optical communication applications. Yet, the scaling of the on‐chip optical emitters to a large number is still challenging, concerning difficulties in packaging and control. Here, we demonstrate a compact 2D beam steering device working as a focal plane array (FPA) on the x‐cut thin‐film lithium tantalate platform. An ideal binary electrode coding scheme is implemented to construct a cascaded switching network, made possible by the low‐energy and high‐speed electro‐optical tuning of the platform. The input light is programmably routed to 16‐channel output grating emitters using only four control electrodes, significantly reducing the fan‐out complexity. Discrete beam steering is implemented by the FPA principle, while continuous beam deflection is realized via wavelength tuning in the orthogonal direction. Experimental results reveal a 2D field of view of 24.2° × 8.0°. The Mach–Zehnder interferometer switches exhibit an extinction ratio exceeding 42 dB, an insertion loss of 0.67 dB, a transient response below 5 ns, and a switching energy of ∼6.25 nJ. Furthermore, the device demonstrates power handling up to 25.5 dBm on‐chip optical power. The present FPA architecture offers a practical solution to chip‐scale optical beam‐steering scaling.