TrinamiX 3D Sensor Paper

BASF spinoff Trimamix publishes an arxiv.org paper "Focus-Induced Photoresponse: a novel optoelectronic distance measurement technique" by Oili Pekkola, Christoph Lungenschmied, Peter Fejes, Anke Handreck, Wilfried Hermes, Stephan Irle, Christian Lennartz, Christian Schildknecht, Peter Schillen, Patrick Schindler, Robert Send, Sebastian Valouch, Erwin Thiel, and Ingmar Bruder.

"Here we introduce Focus-Induced Photoresponse (FIP), a novel method to measure distances. In a FIP-based system, distance is determined by using the analog photoresponse of a single pixel sensor. This means that the advantages of high-density pixelation and high-speed response are not necessary or even relevant for the FIP technique. High resolution can be achieved without the limitations of pixel size, and detectors selected for a FIP system can be orders of magnitude slower than those required by ToF based ones. A system based on FIP does not require advanced sensor manufacturing processes to function, making adoption of unusual sensors more economically feasible.

In the FIP technique, a light source is imaged onto the photodetector by a lens. The size of its image depends on the position of the detector with respect to the focused image plane. FIP exploits the nonlinearly irradiance-dependent photoresponse of semiconductor devices. This means that the signal of a photodetector not only depends on the incident radiant power, but also on its density on the sensor area, the irradiance. This phenomenon will cause the output of the detector to change when the same amount of light is focused or defocused on it. This is what we call the FIP effect."