&lt;title&gt;Optical encoder measurement technology&lt;/title&gt;

Iordache, I.; Bojan, Mihaela; Apostol, D.; Damian, V.; Garoi, F.; Logofatu, C.; Müller, Raluca; Savu, B.

doi:10.1117/12.741862

Cited by 5 publications

(2 citation statements)

References 7 publications

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“…Eddy-current sensors are not sensitive to the ambient conditions but their response is nonlinear with the displacement, which means each eddy-current sensor needs individual calibration. Optical encoders can achieve a resolution of few nanometers by digitally interpolating the diffraction fringes [12], but the practical small signal-noise-ratio limits the resolution. Laser-interferometerbased sensors, such as Fabry-Perot and Michelson interferometers, are extensively used as displacement sensors and calibration tools due to their high precision, good stability, repeatability, and antielectromagnetic interference [13].…”

Section: Introductionmentioning

confidence: 99%

Subnanometer resolution displacement sensor based on a grating interferometric cavity with intensity compensation and phase modulation

Wang

Bai

et al. 2015

Appl. Opt.

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A subnanometer resolution displacement sensor based on a grating interferometric cavity with intensity compensation and phase modulation is proposed and experimentally demonstrated in this paper. The grating interferometric cavity is composed of a frequency-stabilized laser source, a diffraction grating, and a mirror. To realize a subnanometer resolution, the intensity compensation and phase modulation technique are introduced, which are achieved by an intensity compensation light path, three closed placed photodetectors, a processing circuit and a piezoelectric ceramic transducer, and a lock-in amplifier. The intensity compensation technique can improve the stability of the output intensity signal greatly while the phase modulation technique can increase the signal-tonoise ratio dramatically. The detected signal is intensity modulated and processed by a particular arithmetic circuit. Experimental results indicate that the sensitivity of this displacement sensor is 44.75 mV/nm and the highest resolution can reach 0.017 nm, which is 27 times better than the one without intensity compensation and phase modulation. As a high-performance sensor with immunity to electromagnetic interference, this displacement sensor has potential to be used in nanoscience and technology.

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Section: Introductionmentioning

confidence: 99%

Subnanometer resolution displacement sensor based on a grating interferometric cavity with intensity compensation and phase modulation

Wang

Bai

et al. 2015

Appl. Opt.

View full text Add to dashboard Cite

show abstract

“…It is low cost, reliable, and widely used, but requires specific magnetic coupling calibration and electromagnetic shielding. Similar to magnetic encoder, the optical encoder [6] consists of a disc that cuts the window equidistantly on the circumference, light source, and photosensitive sensor. It has high measurement accuracy, but it is very expensive and greatly influenced by the environment (shock, vibration etc.).…”

Section: Introductionmentioning

confidence: 99%