Monolythically Integrated Optical Distance Measurement Sensor with Double-Cathode Photodetector

The presented distance measurement sensor is implemented as an opto-electronic integrated circuit (OEIC) in a modified 0.6 mum BiCMOS technology. The measurement principle is based on the determination of the phase shift between a received optical signal and an electrical modulation signal. The newly developed double-cathode photodetector (DCP) performing the opto-electronic correlation and the all-passive read-out circuit are implemented on a single chip. By using the DCP the fill factor is greatly improved compared to K. Oberhauser et al (2006). For an optical active area of A_pd = 115times120 mum² a very high fill factor of eta_fill = 67 % is reached. The sensor is capable of measuring distances up to s_d = 6.2 m with an optical transmitted power of P_opt = 1.2 mW at a wavelength of lambda = 650 nm.