Amorphous silicon intrinsic photomixing detector for optical ranging

Abstract

Today’s optical range finders or 3D imagers suffer from significant drawbacks and do not allow to combine performance (sensitivity, precision) with simplicity, and scalability enabling very-large scale integration with minimum footprint. Here, we present the amorphous silicon Intrinsic Photomixing Detector (IPD) for direct and highly sensitive optical envelope mixing. The ability to generate a photocurrent that is proportional to the nonlinear mixing of two optical modulation envelope functions enables high performance Time-of-Flight optical ranging at low light levels down to $$\sim \!0.1\,{{{{{\rm{mW}}}}}}{{{{{\rm{cm}}}}}}^{-2}$$ ~ 0.1 mW cm − 2 at $$444\,{{{{{\rm{nm}}}}}}$$ 444 nm . The IPD exceeds MHz bandwidth, covers a broad distance detection range from $$10\,{{{{{\rm{cm}}}}}}$$ 10 cm to $$101\,{{{{{\rm{m}}}}}}$$ 101 m , and achieves a mean depth resolution below $$44\,{{{{{\rm{mm}}}}}}$$ 44 mm for distances up to $$25\,{{{{{\rm{m}}}}}}$$ 25 m . The IPD paves the way towards simple but high-performance photodetectors that allow for very-large scale integration on top of silicon or flexible electronics at low costs with pixel fill factors up to 100%.