title: CMOS-compatible 2-bit optical spectral quantization scheme using a silicon-nanocrystal-based horizontal slot waveguide.
abstract: All-optical analog-to-digital converters based on the third-order nonlinear effects in silicon waveguide are a promising candidate to overcome the limitation of electronic devices and are suitable for photonic integration. In this paper, a 2-bit optical spectral quantization scheme for on-chip all-optical analog-to-digital conversion is proposed. The proposed scheme is realized by filtering the broadened and split spectrum induced by the self-phase modulation effect in a silicon horizontal slot waveguide filled with silicon-nanocrystal. Nonlinear coefficient as high as 8708 W(-1)/m is obtained because of the tight mode confinement of the horizontal slot waveguide and the high nonlinear refractive index of the silicon-nanocrystal, which provides the enhanced nonlinear interaction and accordingly low power threshold. The results show that a required input peak power level less than 0.4 W can be achieved, along with the 1.98-bit effective-number-of-bit and Gray code output. The proposed scheme can find important applications in on-chip all-optical digital signal processing systems.
authors.affiliation: State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box72 (BUPT), Beijing, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Kang
authors.affiliation: 1] State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box72 (BUPT), Beijing, China [2] Photonics Research Centre, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box72 (BUPT), Beijing, China.
authors.forename: Xianting
authors.initials: X
authors.lastname: Zhang
authors.affiliation: 1] State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box72 (BUPT), Beijing, China [2] Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin, Ireland.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box72 (BUPT), Beijing, China.
authors.forename: Xinzhu
authors.initials: X
authors.lastname: Sang
authors.affiliation: Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin, Ireland.
authors.forename: Gerald
authors.initials: G
authors.lastname: Farrell
authors.affiliation: State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box72 (BUPT), Beijing, China.
authors.forename: Chongxiu
authors.initials: C
authors.lastname: Yu
authors.affiliation: Photonics Research Centre, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Photonics Research Centre, Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Hwa Yaw
authors.initials: HY
authors.lastname: Tam
authors.affiliation: Photonics Research Centre, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: P K A
authors.initials: PK
authors.lastname: Wai