Precise detection of two-dimensional displacement based on nonlinear lateral photovoltaic effect

Although the lateral photovoltaic effect (LPE) can be used to detect very small displacement owing to its linear characteristic of the lateral photovoltage (LPV) response to laser position, the effective measurement is limited only within the one-dimensional (1D) region between two contacts. In this work, we report a way to detect two-dimensional (2D) displacement based on a nonlinear LPE in a metal-semiconductor (MS) structure. In addition, compared with the conventional 1D method, this 2D detection possesses a much higher precision owing to its independence of LPV sensitivity of the structure, indicating it as a candidate for the new type of MS-based 2D photoelectric devices. (C) 2010 Optical Society of America