Researchers have developed a post-processing technique for fused silica microlenses, fabricated using femtosecond laser-induced chemical etching (FLICE). This method employs inert gas plasma at atmospheric pressure, allowing for a significant improvement in the surface quality of the lenses. The FLICE technique is promising for the manufacturing of complex micro-optics, but often leaves residual surface roughness that can degrade optical performance. The new approach addresses this limitation, paving the way for more demanding applications.

The inert gas plasma post-processing is applied after the chemical etching phase. By subjecting the microlenses to this plasma, a substantial reduction in surface roughness is achieved, smoothing microscopic imperfections. This is crucial for optical devices where light scattering and aberrations must be minimized, such as in high-resolution imaging systems or fiber optic coupling. The ability to operate at atmospheric pressure simplifies equipment and reduces operational costs compared to vacuum plasma techniques.

The improvement in surface quality obtained with this post-processing is a significant advance for the integration of FLICE microlenses into advanced optical systems. By offering a smoother surface, these microlenses can achieve superior optical performance, making them suitable for applications in fields like integrated photonics, near-field microscopy, and biomedical sensors. This development brings the fabrication of precision optical components at micro and nanoscale closer with greater efficiency and quality.