Nanometer displacement measurement based on metrological self-mixing grating interferometer traceable to the pitch standard of one-dimension chromium self-traceable grating

TL;DR

This paper introduces a novel nanometer displacement measurement method using a metrological self-mixing grating interferometer traceable to a chromium self-traceable grating, enhancing measurement accuracy and environmental stability in nanometrology.

Contribution

It presents the first implementation of a self-mixing grating interferometer based on chromium traceable gratings, establishing a new traceability chain for nanometer length measurement.

Findings

Measurement error is within 0.2366% of commercial interferometers.

The system's phase is directly traceable to the grating pitch.

The method improves environmental robustness in nanometer measurements.

Abstract

Traceability of precision instrument and measuring method is the core issue in metrology science. In the field of nanometer length measurement, the laser interferometers are usually used to trace the measurement value to the laser wavelength, but the laser wavelength is sensitive to the environment disturbance. Chromium self-traceable grating is an ideal nanometer length reference grating with pitch traceability, fabricated by the atomic lithography technique. The new nanometer length traceability chain can be established based on the pitch traceability of chromium self-traceable grating, which is often used to calibrate the systematic error of the atomic force microscope. In this paper, the metrological self-mixing grating interferometer based on the chromium self-traceable grating (SMGI-Cr) is firstly established, whose interfere phase is traceable to the pitch of the chromium self-traceable grating directly and traceable to the chromium atomic transition frequency of energy level 7 S 3 to 7 P 4 indirectly. The nanometer displacement measurement is also achieved by the SMGI-Cr. The measurement error is no more than 0.2366%, compared to a commercial interferometer.