We report fabrication techniques of<i>a</i>-Si:H/SiO<sub><i>x</i></sub>:H multilayers having ample thickness and flat layer boundaries for high performance laminated polarization splitters (LPS’s). In the new fabrication process we used the following techniques to achieve low stress and high surface flatness: SiO<sub><i>x</i></sub>:H film deposition by rf sputtering with a mixture of Ar/H<sub>2</sub>, two-step deposition using rf bias sputtering, and elimination of surface roughness and defects by mechanical polishing. This process enabled deposition of a multilayer as thick as 265 μm while preserving layer boundaries as flat as 1 nm (rms). As a result, LPS’s having low loss, a large aperture, and a long splitting distance were successfully obtained. The high optical performance is applicable to functional devices integrated into fibers or planar waveguides.
© 1998 Optical Society of America
(220.0220) Optical design and fabrication : Optical design and fabrication
Takashi Sato, Norimitsu Sugiyama, Jun Ohno, and Shojiro Kawakami, "Fabrication of High Performance Laminated Polarization Splitters Consisting of Thick a-Si:H /SiOx:H Multilayers," Appl. Opt. 37, 2424-2428 (1998)