Optical encoder based on a nondiffractive beam II.

In a previous work, we introduced the design of an optical encoder based on a nondiffractive beam and demonstrated that it generates a suitable output sinusoidal signal [Appl. Opt.47, 2201-2206 (2008)]. In this work, we experimentally, analytically, and numerically study the dependence of the system performance on its parameters (grating pitch, photodetector size, etc.) and propose three different optimization criteria for which the tolerance to variations in the system parameters is also analyzed. We conclude that the proposed design generates a suitable output signal, with high contrast and very low harmonic distortion, while having a remarkable tolerance to variations in its parameters and to mechanical perturbations.