Si photonic crystal optical antenna serial array and frequency-modulated continuous-wave light detection and ranging action

Photonic crystal waveguide slow-light grating emits a free-space optical beam and steers it widely by changing the wavelength or refractive index. In reverse process, returned light is coupled into device again. We have proposed to use this transmission reception antenna as scanner for detection ranging (LiDAR). Ideally, large-aperture can narrow enhance efficiency. Actually, however, performance not scalable owing loss even though simply lengthened. A serial array configuration in which divided multiple antennas effective mitigating problem. study, we fabricated such using Si photonics technology obtained small divergence of 0.02° at telecom wavelength. Then, observed operation adding an setup frequency-modulated continuous-wave (FMCW) LiDAR confirmed that improved intensity 12 dB. Moreover, FMCW chip were integrated parallel with switch trees Ge photodiodes point cloud images two-dimensional scanning.