Fig. 1. Schematic diagram of the OPA and the control system. (i) Edge coupler; (ii) MMI beam-splitter tree; (iii) thermo-optic PS array; (iv) metal pads connected to PS; (v) emitting antenna array.

Fig. 2. The OPA chip and its structure. (a) Photograph of the OPA chip on a copper-based PCB board; (b) microscopic photograph of gold wire bonding the OPA chip and PCB board; (c) silicon nitride OPA at 532 nm; (d) laser turned on the above chip; (e) a 1 × 2 MMI beam splitter; (f) design layout of the 32-channel PS; (g) microscopic photograph of the 32-channel grating antenna.

Fig. 3. High-speed control system. (a) Block diagram of the control system; (b) 64-channel DAC module with four chips.

Fig. 4. Setup of OPA measurement system including a high-speed electrical control system and optical measurements. (a) Schematic; (b) photograph.

Fig. 5. Normalized light intensity curves before (left) and after (right) calibration.

Fig. 6. OPA outgoing beam scanning at a 6° interval. (a) Far-field image; (b) corresponding SLSR and FWHM.