An integrated parity-time symmetric wavelength-tunable single-mode microring laser

• Published in: Nature communications 2017-05, Vol.8 (1), p.15389-15389, Article 15389
• Main Authors: Liu, Weilin, Li, Ming, Guzzon, Robert S., Norberg, Erik J., Parker, John S., Lu, Mingzhi, Coldren, Larry A., Yao, Jianping
• Format: Article
• Language: English
• Subjects: 639/624/1020/1093; 639/624/1075/1079; 639/624/1075/401; 639/624/399/1097; Genetic algorithms; Humanities and Social Sciences; Lasers; multidisciplinary; Science; Science (multidisciplinary); Symmetry
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15389

Mode control in a laser cavity is critical for a stable single-mode operation of a ring laser. In this study we propose and experimentally demonstrate an electrically pumped parity-time (PT)-symmetric microring laser with precise mode control, to achieve wavelength-tunable single-mode lasing with an improved mode suppression ratio. The proposed PT-symmetric laser is implemented based on a photonic integrated circuit consisting of two mutually coupled active microring resonators. By incorporating multiple semiconductor optical amplifiers in the microring resonators, the PT-symmetry condition can be achieved by a precise manipulation of the interplay between the gain and loss in the two microring resonators, and the incorporation of phase modulators in the microring resonators enables continuous wavelength tuning. Single-mode lasing at 1,554.148 nm with a sidemode suppression ratio exceeding 36 dB is demonstrated and the lasing wavelength is continuously tunable from 1,553.800 to 1,554.020 nm. The breaking of parity-time symmetric gain and loss profiles can be used to achieve single-mode lasing in coupled microring resonators. Here, Liu et al . show that this effect can be electrically controlled with a tunable lasing wavelength and strong sidemode suppression.