title: Bidirectional grating coupler based optical modulator for low-loss integration and low-cost fiber packaging.
abstract: We proposed and demonstrated a novel optical modulator based on a bidirectional grating coupler designed for perfectly vertical fiber coupling. The grating functions as the fiber coupler and 3-dB splitter. To observe the interference, an arm difference of 30μm is introduced. As a result of the high coupling efficiency and near perfect split ratio of the grating coupler, this device exhibits a low on-chip insertion loss of 5.4dB (coupling loss included) and high on-off extinction ratio more than 20dB. The modulation efficiency is estimated to be within 3-3.84V•cm. In order to investigate the fiber misalignment tolerance of this modulator, misalignment influence of the static characteristics is analyzed. 10Gb/s Data transmission experiments of this device are performed with different fiber launch positions. The energy efficiency is estimated to be 8.1pJ/bit.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
authors.forename: Zanyun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Beiju
authors.initials: B
authors.lastname: Huang
authors.forename: Zan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Chuantong
authors.initials: C
authors.lastname: Cheng
authors.forename: Hongda
authors.initials: H
authors.lastname: Chen
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*