Rib and strip chalcogenide waveguides based on Ge–Sb–Se radio-frequency sputtered films

Rib and strip chalcogenide waveguides were demonstrated using photolithography technique and reactive ion beam etching method in a CF4/Ar atmosphere, based on Ge–Sb–Se films deposited by radio-frequency sputtering. The study of compositional, morphological and structural characteristics of the films was investigated, the propagation losses with different widths were measured and optical performance in rib and strip waveguides with different sizes were analyzed and compared. The thin films showed similar composition identical to the bulk glass targets with very low surface roughnesses. The fabricated waveguides by reactive ion beam etching had low surface roughnesses and reasonable vertical sidewalls. Propagation losses of rib and strip waveguides were measured at 1550 nm with different widths, and the methods to decrease the propagation losses were introduced. The techniques were indicated feasible for fabricating rib and strip waveguides with potential applications of integrated optics fields in further study.

► Radio-frequency sputtering and RIBE technique were used to fabricate thin films and waveguides respectively.
► Two types of waveguides, rib and strip waveguides were fabricated, and propagation characteristic was compared with different widths of waveguides.
► Optical characteristics were measured and calculated by various methods and instruments.
► The loss values with different widths of waveguides were analyzed and methods of decreasing the propagation losses were introduced.