title: Loss-induced suppression and revival of lasing.
abstract: Controlling and reversing the effects of loss are major challenges in optical systems. For lasers, losses need to be overcome by a sufficient amount of gain to reach the lasing threshold. In this work, we show how to turn losses into gain by steering the parameters of a system to the vicinity of an exceptional point (EP), which occurs when the eigenvalues and the corresponding eigenstates of a system coalesce. In our system of coupled microresonators, EPs are manifested as the loss-induced suppression and revival of lasing. Below a critical value, adding loss annihilates an existing Raman laser. Beyond this critical threshold, lasing recovers despite the increasing loss, in stark contrast to what would be expected from conventional laser theory. Our results exemplify the counterintuitive features of EPs and present an innovative method for reversing the effect of loss.
authors.affiliation: Department of Electrical and Systems Engineering, Washington University, St. Louis, MO 63130, USA.
authors.forename: B
authors.initials: B
authors.lastname: Peng
authors.affiliation: Department of Electrical and Systems Engineering, Washington University, St. Louis, MO 63130, USA. ozdemir@ese.wustl.edu yang@ese.wustl.edu.
authors.forename: S K
authors.initials: SK
authors.lastname: Özdemir
authors.affiliation: Institute for Theoretical Physics, Vienna University of Technology, A-1040 Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Rotter
authors.affiliation: Department of Electrical and Systems Engineering, Washington University, St. Louis, MO 63130, USA.
authors.forename: H
authors.initials: H
authors.lastname: Yilmaz
authors.affiliation: Institute for Theoretical Physics, Vienna University of Technology, A-1040 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Liertzer
authors.affiliation: Department of Electrical and Systems Engineering, Washington University, St. Louis, MO 63130, USA.
authors.forename: F
authors.initials: F
authors.lastname: Monifi
authors.affiliation: Department of Physics, Washington University, St. Louis, MO 63130, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Bender
authors.affiliation: Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198, Japan. Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: F
authors.initials: F
authors.lastname: Nori
authors.affiliation: Department of Electrical and Systems Engineering, Washington University, St. Louis, MO 63130, USA. ozdemir@ese.wustl.edu yang@ese.wustl.edu.
authors.forename: L
authors.initials: L
authors.lastname: Yang