Session Index

Metasurfaces are planar devices containing nanoantennas or resonator arrays that allow for beam shaping, super resolution imaging, and holography. Metasurface holography technology combines a computer-generated hologram with a nanoscale device. Hybrid metasurfaces with tunable phase change materials provide a platform for active modulation of wavefronts. and opportunities for switchable functionalities.

 

Fringe projection profilometry is a powerful and useful tool in three-dimensional measurements for many applications. We present a scanning approach using fringe projection in different shallow depth of fields along z-axis to retrieve and rebuild the surface of a small inspected object. The designed fringe pattern is projected on the inspected object with a shallow depth of field. Then, a CCD is used to capture the image of the inspected object with projected fringe in a narrow depth of field. A 2D contour of the inspected surface addressed by the in-focused fringes is obtained in one scanning process. The retrieved images from the scanning process are assembled to build the 3D surface of the inspected object. Based on the limited depth-of-field of the pattern projection system and the limited depth-of-focus of the image acquisition system, the precision of the profilometry system is improved.

 

In this study, we proposed optical configurations to fabricate radial grating and use fabricated grating to measure a rotation angle of a rotational stage. The grating period of radial grating gradually changes with the radius, so it has the advantage of multiple angular resolutions.

 

Different from other simulations, we developed a matrix-based simulation model for the optical force on the arbitrary sample under an arbitrary light field. To testify the accuracy of this model, this paper shows the simulation and experimental result for the uniform spherical sample under the Gaussian beam.