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The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
Wide measurement range scanning heterodyne interferometer utilizing astigmatic position sensing scheme.
Youngkyu Park1, Kyoung-Eop Kim, Seong-Jin Kim
1Department of Physics, Sogang University, One Sinsu-Dong, Mapo-Gu, Seoul, 121-742, Korea.
Optics Letters
|August 18, 2011
Summary
A novel scanning heterodyne interferometer overcomes phase ambiguity for precise measurements. This system expands the vertical measurement range to 16 μm, enhancing scanning microscopy capabilities for rough surfaces.
Area of Science:
- Optical Metrology
- Interferometry
- Surface Characterization
Background:
- Phase ambiguity in interferometry limits measurement range.
- Scanning microscopy requires precise vertical measurements.
- Heterodyne interferometry offers high resolution but faces challenges with periodic signals.
Purpose of the Study:
- To propose and validate a scanning heterodyne I/Q-interferometer scheme to resolve phase ambiguity.
- To enhance the vertical measurement range for scanning microscopy applications.
- To demonstrate the system's capability for rough surface analysis.
Main Methods:
- Development of a scanning heterodyne I/Q-interferometer.
- Integration of an astigmatic position sensing scheme in a confocal arrangement.
- Utilizing the interfaced system to retrieve real phase values during scanning.
Main Results:
- Successfully overcame phase ambiguity inherent in periodic interferometric signals.
- Achieved an expanded vertical measurement range of up to 16 μm.
- Demonstrated the system's effectiveness in scanning microscopy of rough surfaces.
Conclusions:
- The proposed scanning heterodyne I/Q-interferometer effectively resolves phase ambiguity.
- The system significantly enhances the vertical measurement range for surface profiling.
- This technique holds potential for advanced scanning microscopy of complex surfaces.
