PERFORMANCE OF AN OPTICAL ENCODER BASED ON A NONDIFFRACTIVE BEAM IMPLEMENTED WITH A SPECIFIC PHOTODETECTION INTEGRATED CIRCUIT AND A DIFFRACTIVE OPTICAL ELEMENT

PEREZ QUINTIAN, FERNANDO; CALARCO NICOLÁS; LUTENBERG, ARIEL; LIPOVETSKY, JOSÉ

APPLIED OPTICS

OPTICAL SOC AMER

Año: 2015

0003-6935

In this article we study the incremental signal produced by an optical encoder based on a non-diffractive beam (NDB). The NDB is generated by means of a diffractive optical element (DOE). The detection system is composed by an Application Specific Integrated Circuit (ASIC) sensor. The sensor consists of an array of eight concentric annular photodiodes, each one provided with a programmable gain amplifier. In this way the system is able to synthesize a non-uniform detectivity. The contrast, amplitude and harmonic content of the sinusoidal output signal are analyzed. The influence of the crosstalk among the annular photodiodes is placed in evidence through the dependence of the signal contrast on the wavelength