University of California

Baicheng Yao

Chee Wei Wong

Xiangfeng Duan

Yuan Liu

Shu-Wei Huang

Abhinav Kumar Vinod

Based on graphene heterostructure in chip-scale silicon nitride microresonators, optoelectronic control and modulation in frequency combs via group velocity dispersion modulation can be demonstrated. By tuning graphene Fermi level from 0.50 eV to 0.65 eV via electric-field gating, deterministic in-cavity group velocity dispersion control from anomalous (&#x2212;62 fs/mm) to normal (+9 fs/mm) can be achieved with Q factor remaining high at 10. Consequently, both the primary comb lines and the full comb spectra can be controllable dynamically with the on/off switching of the Cherenkov radiation, the tuning of the primary comb lines from 2.3 THz to 7.2 THz, and the comb span control from zero comb lines to &#x2dc;781 phase-locked comb lines, directly via the DC voltage.

Graphene microcavity frequency combs and related methods of manufacturing

Methods and apparatus for providing all-optically generated, on-chip propagated and high-efficiency tunable plasmons are described. The plasmon generating apparatus includes a graphene based silicon nitride waveguide (GSiNW) utilizing 'C+L' band light sources and detectors that take advantage of the surface 2nd nonlinearity on graphene. The optical generation is accomplished via one or more optical communication lasers through the difference-frequency generation process. The THz frequency and intensity is tunable via an external gate voltage. Using such a device the optical to THz conversion may be made at least an order of magnitude more efficient than prior THz sources, and can be used to make chip-scale room-temperature THz sources, switches, modulators and detectors based on graphene.

Growing community of inventors

Los Angeles, CA, United States of America

Baicheng Yao