Low-propagation-loss Ta₂O₅ optical waveguides on silica substrate

Abstract

In this paper, a high-refractive-index (∼2.0) and low-propagation-loss tantalum pentoxide (Ta2O5) waveguide is reported. We fabricated Ta2O5 strip optical waveguides with a cross section of 400 nm × 10 µm by chemical solution deposition (CSD) followed by CF4 reactive ion etching. The optimum fabrication steps make it possible to obtain the Ta2O5 strip optical waveguides with a propagation loss of less than 1 dB/cm at 830 nm, which is significant for optoelectronic integrated circuits in the 0.8 µm wavelength range.

Substrate Potential Dependence of Optical Characteristics of a-Si:H for Shortwave Near-infrared Filter by DC and RF Sputtering

“…However, a-Si:H, which is practically used in the field of solar cells, is manufactured using the chemical vapor deposition (CVD) method [5], and it is necessary to establish a manufacturing process, similar to general optical thin films, that is easier to manage. In addition, there is a problem that the optical absorption of the SWNIR band tends to be high, hence it has not been widely put into practical use [6]. To popularize a-Si:H as an optical film for SWNIR, we considered it important to clarify the influence of absorption in the short-wave region and durability, including the characteristics of the application, using a simple and stable film deposition process.…”