Integrated Optical Distance Measurement Detectors

The project goal is the scientific investigation of advanced integrated detectors for optical distance measurement built up with PIN technology, i.e. with very low doped intrinsic (I) regions between P- and N-type zones. Opto electrical integrated circuits (OEICs) include a fast photodetector and a readout circuit, avoid bond pads and wires between photodetector and circuit and therefore possess higher bandwidths compared to discrete setups. This makes OEICs suitable for distance measurement sensors in addition to fast optical receivers. Due to PIN technology fast charge carrier drift is guaranteed, avoiding slow carrier diffusion and further speeding up the detector. It will be shown that especially the new research area of integrated optical distance measurement systems, based on the time- of-flight (TOF) principle, takes advantage of highly linear, very fast and very efficient special multi-electrode PIN photodetectors. The PIN photodetectors are implemented in a BiCMOS technology. Therefore, higher gain, faster and more accurate circuits are possible than with CMOS approaches of other groups. Highest measurement accuracy (<1cm) and largest maximum object distance (>10m) as well as smallest optical pulse power can be aimed at. The distance information is gained by the correlation of the transmitted and the received signal in new approaches already in special photodetectors or in new readout circuits, depending on the sensor concept. The focus, however, will be for the first time on correlation detectors having a PIN structure. These are devices with three to nine electrodes to perform correlation and integration of signals already in the photodetector. Readout circuits also shall be investigated. The multi-electrode correlating detectors allow small pixels enabling multi-pixel arrays on a single chip. Demands on accuracy, sensitivity, minimum chip area and eye safety of the application form physical guidelines for the investigation of this sensor and multi-pixel array with distance information in each pixel being acquired simultaneously. Moving parts as in nowadays scanning three-dimensional cameras will be avoided resulting in an enhanced number of 3D images per second. Application specific integrated circuit (ASIC) services will be used to verify the new approaches experimentally. The primary target of this proposal is the scientific investigation which approach/method is the best for an integrated optical distance measurement system. The group aims at scientific leadership in this challenging research area. The research results may additionally open up applications for automotive, robotics, entertainment and safety industries.

The project goal is the scientific investigation of advanced integrated detectors for optical distance measurement built up with PIN technology, i.e. with very low doped intrinsic (I) regions between P- and N-type zones. Opto electrical integrated circuits (OEICs) include a fast photodetector and a readout circuit, avoid bond pads and wires between photodetector and circuit and therefore possess higher bandwidths compared to discrete setups. This makes OEICs suitable for distance measurement sensors in addition to fast optical receivers. Due to PIN technology fast charge carrier drift is guaranteed, avoiding slow carrier diffusion and further speeding up the detector. It will be shown that especially the new research area of integrated optical distance measurement systems, based on the time- of-flight (TOF) principle, takes advantage of highly linear, very fast and very efficient special multi-electrode PIN photodetectors. The PIN photodetectors are implemented in a BiCMOS technology. Therefore, higher gain, faster and more accurate circuits are possible than with CMOS approaches of other groups. Highest measurement accuracy (<1cm) and largest maximum object distance (>10m) as well as smallest optical pulse power can be aimed at. The distance information is gained by the correlation of the transmitted and the received signal in new approaches already in special photodetectors or in new readout circuits, depending on the sensor concept. The focus, however, will be for the first time on correlation detectors having a PIN structure. These are devices with three to nine electrodes to perform correlation and integration of signals already in the photodetector. Readout circuits also shall be investigated. The multi-electrode correlating detectors allow small pixels enabling multi-pixel arrays on a single chip. Demands on accuracy, sensitivity, minimum chip area and eye safety of the application form physical guidelines for the investigation of this sensor and multi-pixel array with distance information in each pixel being acquired simultaneously. Moving parts as in nowadays scanning three-dimensional cameras will be avoided resulting in an enhanced number of 3D images per second. Application specific integrated circuit (ASIC) services will be used to verify the new approaches experimentally. The primary target of this proposal is the scientific investigation which approach/method is the best for an integrated optical distance measurement system. The group aims at scientific leadership in this challenging research area. The research results may additionally open up applications for automotive, robotics, entertainment and safety industries.