Related Experiment Video
Updated: Jul 11, 2026
08:39
Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
Fringe counting method for synthetic phase with frequency-modulated laser diodes
Ribun Onodera1, Munechika Sakuyama, Yukihiro Ishii
1Department of Electronics, University of Industrial Technology, 4-1-1 Hashimotodai, Sagamihara, Kanagawa 229-1196, Japan. onodera@uitec.ac.jp
The Review of Scientific Instruments
|October 2, 2007
Summary
A new fringe counting method uses two laser diodes (LDs) and an interferometer to measure displacement. This technique enables faster mirror movement detection by creating a synthetic fringe signal.
Area of Science:
- Optics and Photonics
- Metrology
Background:
- Displacement measurement is crucial in various scientific and industrial applications.
- Traditional fringe counting methods can be limited by speed and sensitivity.
Purpose of the Study:
- To develop an advanced fringe counting method for enhanced displacement measurement.
- To improve the speed and accuracy of measuring mirror movement.
Main Methods:
- Constructed a fringe counting system utilizing two frequency-modulated laser diodes (LDs).
- Employed an unbalanced two-beam interferometer with mutually inverted sawtooth current modulation.
- Generated synthetic fringe signals by mixing interference patterns from two LDs.
Main Results:
- Achieved interference fringe signals with opposite signs for respective wavelengths.
- Produced a synthetic fringe signal with reduced sensitivity to synthetic wavelength.
- Enabled faster displacement measurement through synthetic fringe pulses.
Conclusions:
- The developed laser diode fringe counting method enhances displacement measurement capabilities.
- The system allows for faster detection of mirror movement compared to conventional techniques.
- This method offers a promising approach for high-speed metrology applications.
