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    $\mu \text{m}$    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    $\times $    3 mm silicon-photonic chip. The 0.18-   $\mu \text{m}$    CMOS ASIC of the same area comprises the front-end 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.
['Behnam Behroozpour', 'Phillip Sandborn', 'Niels Quack', 'Tae Joon Seok', 'Yasuhiro Matsui', 'Ming C. Wu', 'Bernhard E. Boser']
Electronic-Photonic Integrated Circuit for 3D Microimaging