A slow-light medium based on multiple, closely spaced gain lines is studied. The spacings and relative strengths of the gain lines are optimized by using the criteria of gain penalty and eye-opening penalty to maximize the fractional delay defined in terms of the best decision time for random pulse trains. Both numerical calculations and experiments show that an optimal design of a triple-gain-line medium can achieve a maximal fractional delay about twice that which can be obtained with a single-gain-line medium, at three times higher modulation bandwidth, while high data fidelity is still maintained.
© 2007 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: March 15, 2007
Revised Manuscript: May 1, 2007
Manuscript Accepted: May 11, 2007
Published: July 3, 2007
Zhimin Shi, Ravi Pant, Zhaoming Zhu, Michael D. Stenner, Mark A. Neifeld, Daniel J. Gauthier, and Robert W. Boyd, "Design of a tunable time-delay element using multiple gain lines for increased fractional delay with high data fidelity," Opt. Lett. 32, 1986-1988 (2007)