An integrated electronic-photonic phase-locked loop (PLL) modulates the frequency of a tunable laser for use in frequency-modulated continuous-wave (FMCW) lidar 3D imaging. The proposed lidar can perform 180k range measurements per second. The rms depth precision is 8 mu m at distances of +/- 5 cm from the range baseline. The range window is 1.4 m, with a precision of 4.2 mm at the edges of the window. Optical circuitry, including input light couplers, waveguides, and photodiodes, is realized on a 3 mm x 3 mm silicon-photonic chip. The 0.18-mu m CMOS ASIC of the same area comprises the frontend transimpedance amplifier, analog electro-optical PLL, and digital control circuitry consuming 1.7 mA from a 1.8 V supply and 14.1 mA from a 5-V supply. The latter includes 12.5-mA bias current for the distributed Bragg reflector section of the tunable laser. The two chips are integrated using through-silicon-vias implemented in the silicon-photonic chip.
Tobias Kippenberg, Mikhail Churaev, Xinru Ji, Zihan Li, Alisa Davydova, Junyin Zhang, Yang Chen, Xi Wang, Kai Huang
Kirsten Emilie Moselund, Chang Won Lee
Camille Sophie Brès, Marco Clementi, Jiaye Wu, Qian Li