We demonstrate the controlled enhancement of photoresponsivity in a graphene photodetector by coupling to slow light modes in a long photonic crystal linear defect cavity. Near the Brillouin zone (BZ) boundary, spectral coupling of multiple cavity modes results in broad-band photocurrent enhancement from 1530 nm to 1540 nm. Away from the BZ boundary, individual cavity resonances enhance the photocurrent eight-fold in narrow resonant peaks. Optimization of the photocurrent via critical coupling of the incident field with the graphene-cavity system is discussed. The enhanced photocurrent demonstrates the feasibility of a wavelength-scale graphene photodetector for efficient photodetection with high spectral selectivity and broadband response.
@article{arxiv.1311.2080,
title = {Enhanced Photodetection in Graphene-Integrated Photonic Crystal Cavity},
author = {Ren-Jye Shiue and Xuetao Gan and Yuanda Gao and Luozhou Li and Xinwen Yao and Attila Szep and Dennis Walker, and James Hone and Dirk Englund},
journal= {arXiv preprint arXiv:1311.2080},
year = {2015}
}