Fig. 1. Theoretical model of far-field calculation of one-dimensional optical phased array

Fig. 2. Theoretical model of far-field calculation of two-dimensional optical phased array

Fig. 3. Large scanning field of view optical phased array with different structures. (a) Non-uniform width waveguide array^[18]; (b) sinusoidal waveguide array^[21]; (c) amplitude optimization^[25]; (d) sparse array^[29]

Fig. 4. Thin film lithium niobate optical phased array chip for high-speed beam steering^[30]. (a) Microscope image of the fabricated chip; (b) photo of the chip after optical and electrical packaging

Fig. 5. Two-dimensional scanning results of beam^[30]. (a) Image of far-field beam with phase tuning; (b) optical power distribution with phase tuning; (c) image of far-field beam with wavelength tuning; (d) optical power distribution with wavelength tuning; (e) measured beam divergence angle

Fig. 6. Multidimensional multiplexing optical phased array. (a) Schematic diagram of space division multiplexing; (b) schematic diagram of polarization multiplexing; (c) bi-directional and dual polarization optical phased array^[37]; (d) polarization multiplexing optical phased array^[39]

Fig. 7. Comparison results of performance of different amplitude distributions. (a)(b) Uniform amplitude distribution and corresponding the far-field intensity distribution; (c)(d) Chebyshev amplitude distribution and the far-field intensity distribution

Fig. 8. Two-demensional antenna array of optical phased array. (a) Two-demensional optical phased array of 4×4 antenna array^[44]; (b) large-scale integrated two-dimensional optical phased array of 256×256 antenna array^[45]

Fig. 9. Two-dimensional optical phased array with optimized antenna array. (a) Scalable optical phased array with rectangular sparse array^[47]; (b) 8×8 optical phased array based on 2×8 phase shifter architecture^[48]

Fig. 10. Optical phased array with sparse circular aperture^[49]. (a) Schematic diagram of antenna array; (b) grating-lobe free optical phased array chip

Fig. 11. Optical phased array with frequency-modulated continuous-wave system. (a) Schematic diagram of system; (b) physical picture of distance measurement system