Miniaturized laser interferometer using dynamic current-wavelength modulation for high precision displacement measurement
Journal
Measurement Science and Technology
Journal Volume
36
Journal Issue
1
Start Page
015040
ISSN
0957-0233
1361-6501
Date Issued
2024-12-05
Author(s)
Abstract
This study proposes a compact displacement measurement interferometer facilitated by a novel dynamic current-wavelength modulation method for high-precision displacement measurement. This technique compensates for the modulation depth by precisely predicting the optical path difference with frequency-scanning interferometry to achieve consistent modulation depth over an extensive measurement range. Additionally, a wavelength-locking method was developed for the 1550 nm band, using the P7 absorption peak of hydrogen cyanide gas to lock the central wavelength of the laser. The experimental results showed that the wavelength stability can be kept within 128 fm for 8 h with the proposed method. Furthermore, the deviations are less than 40 nm compared to a calibrated laser interferometer within the 300 mm measurement range. This research offers precise positioning feedback for precision engineering, paving the way for advanced semiconductor manufacturing processes.
Subjects
displacement measurement interferometer (DMI)
dynamic current-wavelength modulation
frequency-scanning interferometry (FSI)
HCN gas
wavelength-locking
Publisher
IOP Publishing
Type
journal article