Theoretical structural dependence of optical power density in horizontal slot waveguides using Nb2O5

• Published in: Japanese Journal of Applied Physics Vol. 58; no. SJ; p. SJJB01
• Main Authors: Hayama, Yoshiki, Nakatsuhara, Katsumi, Ochiai, Toshihiro, Takeda, Masayuki, Nishizawa, Takeshi
• Format: Journal Article
• Language: English
• Published: Tokyo IOP Publishing 01.08.2019; Japanese Journal of Applied Physics
• Subjects: Dependence; Fiber optic communications; Fiber optic networks; Niobium oxides; Ribs (structural); Tolerances; Waveguides
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/1347-4065/ab1e3e

We analyzed the theoretical characteristics of horizontal slot waveguides that consist of two Nb2O5 layers and a narrow gap. The slot waveguides strongly confine light in the low index region in the narrow horizontal slot. The obtained peak optical power density of the horizontal slot waveguides is approximately 3.8 times higher than that of the conventional rib-type waveguide. The dependency of the peak optical power density on the structural parameters was investigated. In addition, the coupling between the rib-type waveguides and the horizontal slot waveguide was simulated. The influence of fabrication tolerances for optical power density was calculated in order to estimate the fabrication tolerances. As a preliminary experiment, a horizontal slot in an Nb2O5 waveguide structure was fabricated. An air slot region less than 30 nm thick was successfully obtained.