Single-mode laser by parity-time symmetry breaking

• DOI: 10.1126/science.1258479
• Publication Date: 2014-10-31T03:19:35Z
• Authors: Liang Feng; Zi Jing Wong; Ren-Min Ma; Yuan Wang; Xiang Zhang
• Keywords: Parity (physics); Optical cavity

Effective manipulation of cavity resonant modes is crucial for emission control in laser physics and applications. Using the concept parity-time symmetry to exploit interplay between gain loss (i.e., light amplification absorption), we demonstrate a symmetry-breaking with that can be controlled at will. In contrast conventional ring lasers multiple competing modes, our microring exhibits intrinsic single-mode lasing regardless spectral bandwidth. Thresholdless breaking due rotationally symmetric structure leads stable operation selective whispering-gallery mode order. Exploration may open door next-generation optoelectronic devices optical communications computing.