Abstract
Analog circuits processing PSD currents and calculating position value introduce errors of significant magnitude and
demand separate circuits for amplitude and phase detection methods, thus prohibiting full use of the PSD’s potential. In
order to demonstrate PSD capabilities, a high performance electronics circuit has been constructed that digitizes PSD
photocurrents and calculates position value using DFT from both amplitude and phase methods. Verification of the total
system error has been independently carried out using Michelson interferometer. Comparison of both detection methods
offers better insight into their potential use. Experimental results qualify PSD as detector capable of 100 nm displacement
resolution in direct illumination setup..
Keywords
Position sensitive detector, Optical position measurement, Photocurrent digitizing, PSD linearity, PSD position
detection error.
Citation
J. M. ELAZAR, S. J. PETRICEVIC, Performance of the position sensitive photodetector with early stage digitizing of the photocurrents, Optoelectronics and Advanced Materials - Rapid Communications, 6, 1-2, January-February 2012, pp.52-57 (2012).
Submitted at: Dec. 12, 2011
Accepted at: Feb. 20, 2012