Meta-Dispersive 3D Chromatic Confocal Measurement

Area of Science:

• Optical Metrology
• Nanophotonics
• 3D Reconstruction

Background:

• Current 3D reconstruction methods using metasurfaces face resolution limitations.
• Existing visual measurement techniques struggle with high-precision 3D sensing.

Purpose of the Study:

• To propose and demonstrate a high-precision 3D measurement method using a dispersive metalens (DML).
• To overcome resolution limitations in current 3D reconstruction technologies.

Main Methods:

• Integration of a dispersive metalens (DML) with the chromatic confocal method.
• Engineered dispersion for linear response and diffraction-limited focusing.
• Experimental validation through longitudinal and transversal measurements.

Main Results:

• Achieved axial accuracy of ±4 µm and subwavelength axial resolution of 0.325 µm.
• Demonstrated lateral resolution exceeding 4.38 µm.
• Successfully reconstructed a 3D USAF-1951 resolution test chart.

Conclusions:

• The DML-based chromatic confocal method enables high-precision 3D measurement.
• This technique shows potential for microstructure characterization and industrial inspection.
• Paves the way for advanced on-chip 3D optical metrology.