Open AccessHigh‐speed focus‐induced photoresponse in amorphous silicon photodetectors for optical distance measurements
Author(s) -
Bablich Andreas,
Müller Maurice,
Kienitz Paul,
Bornemann Rainer,
Bolívar Peter Haring
Publication year - 2022
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/ell2.12450
Subject(s) - photodetector , photodiode , harmonics , materials science , optoelectronics , detector , silicon , frequency response , amorphous silicon , optics , irradiance , bandwidth (computing) , diode , pin diode , amorphous solid , physics , crystalline silicon , electrical engineering , computer science , voltage , telecommunications , engineering , chemistry , organic chemistry
The Focus‐Induced Photoresponse (FIP) enables 3D sensing capabilities by evaluating the irradiance dependent non‐linear detector response in defect‐based materials. Since this advantage is intricately associated to a slow response, the electrical bandwidth of previous FIP sensors is limited to a few kHz only. We report the FIP in amorphous silicon pin photodiodes and propose a sensor read out based on a harmonics analyses. We achieve modulation frequencies of 500 kHz and a non‐linear beat frequency detection up to at least 3.5 MHz, surpassing the bandwidth of state‐of‐the‐art architectures by at least a factor of 175. The FIP sensors further achieve signal‐to‐noise ratios of ∼50 dB, depth resolutions of at least 5.4 mm at 126 cm and a DC FIP detection limit of 1.3 µW/mm 2 .