A parity-time symmetrysingle-mode laser based on graphene

The development of advanced optical systems, especially coherent optical systems demands high-performance single-mode lasers. Here, we proposed a parity-time symmetry single-mode laser based on graphene with superior performance over the widely utilized technologies of the index-coupled DFB laser working at telecommunication wavelength. The unique properties of graphene have been used to tune the III-V/Silicon hybrid laser to the PT symmetry broken phase where the lasing mode has a minimum overlap with graphene nanostructures while all other modes have been suppressed by the loss in graphene. Our results suggest a high-performance silicon-based laser source for photonic integrated circuits. Such a compact single-mode laser source can be widely used in some applications, such as on-chip optical interconnects, optical spectrometry, biochemical sensing and imaging.