Related Experiment Video
Updated: Dec 25, 2025
08:05
Microtensiometer for Confocal Microscopy Visualization of Dynamic Interfaces
Published on: September 9, 2022
2.7K
Dual differential confocal method for surface profile measurement with a large sensing measurement range
Applied Optics
|April 1, 2020
Summary
A novel dual differential confocal method (DDCM) enhances surface profile measurement. This technique achieves a large measurement range and high axial resolution without scanning, improving precision for optical metrology applications.
Area of Science:
- Optical Metrology
- Surface Characterization
- Microscopy Techniques
Background:
- Traditional confocal microscopy faces limitations in achieving both large measurement ranges and high axial resolution simultaneously.
- Accurate surface profile measurement is crucial in various scientific and industrial fields.
Purpose of the Study:
- To introduce a Dual Differential Confocal Method (DDCM) for high-precision surface profile measurement.
- To overcome the trade-off between measurement range and axial resolution in existing confocal techniques.
Main Methods:
- The DDCM processes confocal signals from two pinholes with an axial offset.
- It combines these processed signals to generate an axial response curve with enhanced slope and linearity.
- This approach enables profile measurement without requiring physical axial scanning.
Main Results:
- The DDCM achieved a sensing measurement range of 0.54 µm with an axial resolution of 1 nm at a numerical aperture of 0.9.
- The measurement range of the DDCM was found to be approximately 2.9 times greater than that of standard differential confocal microscopy.
Conclusions:
- The proposed DDCM effectively enhances surface profile measurement capabilities.
- This method offers a significant improvement in both measurement range and axial resolution compared to previous techniques.
