Efficient- and Broadband-Coupled Selective Spot-Size Converters With Damage-Free Graphene Integration Process

Author

Kou, Rai ; Kobayashi, Yoshiyuki ; Warabi, Kaori ; Nishi, Hidetaka ; Tsuchizawa, Tai ; Yamamoto, Takayuki ; Nakajima, Hiromasa ; Yamada, Koji

Author_Institution

NTT Nanophotonics Center, Atsugi, Japan

Volume

6

Issue

3

fYear

2014

fDate

Jun-14

Firstpage

1

Lastpage

9

Abstract

We report an enhancement of coupling efficiency between an optical fiber and graphene photonic device integrated on a silicon photonics platform. The design and optimization of selective spot-size converters (SSSCs) enables low coupling losses of 1.4 dB/facet for TE and 2.4 dB/facet for TM modes without causing damage to the graphene. In order to maximize the potential of the perfect wavelength independent response in the graphene, ultra-broad-bandwidth coupling from O- to U-bands (1300-1650 nm) is characterized. The bandwidth is over 300 nm (at 3-dB roll off) in both polarization modes. We integrated the SSSCs with a partially graphene integrated silicon-ring resonator to substantiate the wavelength response improvement by a pico-meter-order high-resolution spectroscopy.

Keywords

elemental semiconductors; graphene; integrated optics; optical design techniques; optical fibre couplers; optical fibre losses; optical fibre polarisation; optical resonators; optimisation; silicon; C-Si; O-band; SSSC design; U-band; broadband-coupled selective spot-size converters; coupling efficiency; damage-free graphene integration process; graphene photonic device; low coupling losses; optical fiber; optimization; perfect wavelength independent response; picometer-order high-resolution spectroscopy; polarization modes; silicon photonics platform; silicon-ring resonator; ultrabroad bandwidth coupling; wavelength 1300 nm to 1650 nm; Couplings; Graphene; Optical device fabrication; Optical fibers; Optical polarization; Silicon; Photonic device integration; fiber coupling; graphene integration;

fLanguage

English

Journal_Title

Photonics Journal, IEEE

Publisher

ieee

ISSN

1943-0655

Type

jour

DOI

10.1109/JPHOT.2014.2323297

Filename

6814819