Plasma deposition of anti-reflective coatings
on spherical lenses

Plasma-enhanced chemical vapor deposition (PECVD) was used to fabricate multilayer anti-reflective coatings (ARCs) on spherical fiber couplers. Two- and four-layer designs were applied for single- and double-band ARCs centered at 1300 nm and 1550 nm, respectively. The systems consist of SiO2 as a low index material, and SiN1.3 or TiO2 as high index materials, obtained from different precursors (SiH4, SiCl4, and TiCl4). The deposition was controlled in-situ by single wavelength (632.8 nm) reflection monitoring. The optical and mechanical performance of the lenses was evaluated and related to the deposition conditions and the film microstructure.