Focus-Induced Photoresponse (FIP) is a patented monocular technology for optical distance measurements [1]. It relies on physical phenomena which are fundamentally different from established technologies such as time-of-flight, stereo vision, structured light or systems based on image processing. In this presentation, the underlying principles of the technology as well as application examples are introduced.
FIP exploits the nonlinear transient photoresponse of various organic as well as inorganic semiconductors when exposed to optical radiation. When a light-emitting (or reflecting) object moves in and out of focus, the size of the image that it creates on a sensor surface determines the magnitude of the photoresponse. As the focal point shifts with the distance between the collecting lens and the object, the sensor response yields a unique signature for every distance.
The device layout can hence be simple: the main components are modulated light sources, a lens and a non-pixelated sensor. Due to the unstructured sensor, resolution is not restricted by pixel size. FIP does not require large computational power as neither image processing nor stereo vision is required. By proper choice of optics and sensor type, the system can be adapted to any measuring task. We have successfully demonstrated functionality for wavelengths from visible light to IR and for distances up to 100 m.
[1] Bruder et al. (US 9,001,029 B2) DETECTOR FOR OPTICALLY DETECTING AT LEAST ONE OBJECT.
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