Abstract

We develop a process of fabricating silicon waveguides and devices using a bulk silicon substrate. The fabrication process mainly consists of one silicon dry etching and one silicon wet etching. The use of silicon wet etching makes the process simple and inexpensive. Because of the anisotropic nature of silicon wet etching, the bulk-silicon-based (BSB) waveguide made by the process consists of an inverted-trapezoidal core on a rectangular pedestal and a trapezoidal base beneath the pedestal. In addition, geometrically smooth BSB waveguide bends can be achieved when the radii of curvature of the bends are sufficiently large. The propagation loss of the BSB waveguide depends on wet etching conditions and it is 4.0 or 0.79 dB/cm for transverse-magnetic polarization. It is confirmed that the minimum radius of curvature of the BSB waveguide bend is 500 μm. The BSB waveguides and bends are expected to be used to implement low-cost sensors with simple geometry.

Sub-micron silicon nitride waveguide fabrication using conventional optical lithography

Yuewang Huang, Qiancheng Zhao, Lobna Kamyab, Ali Rostami, Filippo Capolino, and Ozdal Boyraz
Opt. Express 23(5) 6780-6786 (2015)

Fabrication and characterization of straight and compact S-bend optical waveguides on a silicon-on-insulator platform

Rupesh Kumar Navalakhe, Nandita DasGupta, and Bijoy Krishna Das
Appl. Opt. 48(31) G125-G130 (2009)

Etch-free low loss silicon waveguides using hydrogen silsesquioxane oxidation masks

Maziar P. Nezhad, Olesya Bondarenko, Mercedeh Khajavikhan, Aleksandar Simic, and Yeshaiahu Fainman
Opt. Express 19(20) 18827-18832 (2011)

Silicon slot fin waveguide on bonded double-SOI for a low-power accumulation modulator fabricated by an anisotropic wet etching technique

James Byers, Kapil Debnath, Hideo Arimoto, M. Khaled Husain, Moise Sotto, Zuo Li, Fayong Liu, Kouta Ibukuro, Ali Khokhar, Kian Kiang, Stuart A. Boden, David J. Thomson, Graham T. Reed, and Shinichi Saito
Opt. Express 26(25) 33180-33191 (2018)

Alignment method combining interference lithography with anisotropic wet etch technique for fabrication of high aspect ratio silicon gratings

Yanchang Zheng, Keqiang Qiu, Huoyao Chen, Yong Chen, Zhengkun Liu, Ying Liu, Xiangdong Xu, and Yilin Hong
Opt. Express 22(19) 23592-23604 (2014)