Optical encoder based on a non diffractive beam

LUTENBERG, ARIEL; PEREZ QUINTIAN, FERNANDO; REBOLLO, MARÍA A.

APPLIED OPTICS

Año: 2007

0003-6935

Optical encoders are used in industrial and laboratory motion equipment to measure rotations and linear displacements. In this work we introduce a design of an optical encoder based on a non diffractive beam. We expect that the invariant profile and radial symmetry of the non diffractive beam provide the design with remarkable tolerance to mechanical perturbations. We experimentally demonstrate that the proposed design generates a suitable output sinusoidal signal, with very low harmonic distortion. Moreover, we present a numerical model of the system, based on the angular spectrum approximation, whose predictions are in excellent agreement with the experimental results.