Observation of superluminal and slow light propagation in erbium-doped optical fiber

¹ The Institute of Optics, University of Rochester - Rochester, NY 14627, USA
² San Francisco State University - San Francisco, CA 94132, USA
³ The United States Air Force Academy - Colorado Springs, CO 80840, USA
⁴ Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Zaragoza Pedro Cerbuna 12, 50009 Zaragoza, Spain

Received: 1 September 2005
Accepted: 9 November 2005

Abstract

We observe both extremely slow and superluminal pulse propagation speeds at room temperature in an erbium-doped fiber (EDF). A signal at 1550 is sent through an erbium-doped fiber with varying powers of a 980 pump. The degree of signal delay or advancement is found to depend significantly on the pump intensity. We observe a maximum fractional advancement of 0.124 and a maximum fractional delay of 0.089. The effect is demonstrated both for a sinusoidally modulated signal and for Gaussian pulses. The ability to control the sign and magnitude of the pulse velocity could have important implications for applications in photonics.