title: Superluminal ring laser for hypersensitive sensing.
abstract: The group velocity of light becomes superluminal in a medium with a tuned negative dispersion, using two gain peaks, for example. Inside a laser, however, the gain is constant, equaling the loss. We show here that the effective dispersion experienced by the lasing frequency is still sensitive to the spectral profile of the unsaturated gain. In particular, a dip in the gain profile leads to a superluminal group velocity for the lasing mode. The displacement sensitivity of the lasing frequency is enhanced by nearly five orders of magnitude, leading to a versatile sensor of hyper sensitivity.
authors: Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL 60208, USA. h-yum@northwestern.edu
authors: H N
authors: HN
authors: Yum
authors: M
authors: M
authors: Salit
authors: J
authors: J
authors: Yablon
authors: K
authors: K
authors: Salit
authors: Y
authors: Y
authors: Wang
authors: M S
authors: MS
authors: Shahriar
mesh_terms: D004867:Equipment Design; D006112:Gravitation; D007834:Lasers; D008027:Light; D049449:Luminescence; D008962:Models, Theoretical; D055095:Optics and Photonics / Q000295:instrumentation* / Q000379:methods*; D012399:Rotation