3D mapping of intensity field about the focus of a micrometer scale parabolic mirror

TL;DR

This paper presents the fabrication and detailed 3D optical characterization of micrometer-scale parabolic mirrors, demonstrating diffraction-limited focusing with sub-micron beam waists and validating results with simulations.

Contribution

It introduces a method for fabricating and characterizing parabolic micromirrors at the micrometer scale, with experimental results closely matching theoretical predictions.

Findings

Achieved sub-micron beam waists with 10 μm aperture mirrors

Demonstrated diffraction-limited focusing performance

Validated experimental results with angular spectrum simulations

Abstract

We report on the fabrication and diffraction-limited characterization of parabolic focusing micromirrors. Sub - micron beam waists are measured for mirrors with 10 {\mu}m radius aperture and measured fixed focal lengths in the range from 24 {\mu}m to 36 {\mu}m. Optical characterization of the 3D intensity in the nearfield produced when the device is illuminated with collimated light is performed using a modified confocal microscope. Results are compared directly with angular spectrum simulations, yielding strong agreement between experiment and theory, and identifying the competition between diffraction and focusing in the regime probed.