Summary
This study introduces a noncontact optical technique for precise surface profile measurement with angstrom-level height sensitivity. The common path heterodyne interferometer offers detailed surface analysis, including stability and repeatability.
Area of Science:
- Optical Metrology
- Surface Science
- Interferometry
Background:
- Accurate surface characterization is crucial in various scientific and industrial fields.
- Existing surface measurement techniques may have limitations in sensitivity or contact requirements.
Purpose of the Study:
- To present a novel noncontact optical technique for high-sensitivity surface profile measurement.
- To demonstrate the capabilities of a common path heterodyne interferometer for detailed surface analysis.
Main Methods:
- Utilizing a common path heterodyne interferometer with two orthogonally polarized beams of slightly different frequencies.
- Employing one beam as a reference and the other to circularly scan the surface.
- Measuring surface height through the phase of the beat frequency of interfering return beams.
Main Results:
- Achieved height sensitivity of the order of 1 Angstrom.
- Generated graphical displays of surface profile, autocovariance function, and spectral density function.
- Evaluated measurement stability and repeatability, with comparisons to other instruments.
Conclusions:
- The developed noncontact optical technique provides high-precision surface profiling.
- The common path heterodyne interferometer is a versatile tool for comprehensive surface characterization.
- This method offers significant advantages for applications requiring angstrom-level surface measurement accuracy.
