We use a tight-binding formalism in the time domain to analyze the effect of resonant gain enhancement and spontaneous emission noise in amplifying coupled-resonator optical waveguides (CROWs). We find the net amplification of a wave propagating in a CROW does not always vary with the group velocity, and depends strongly on the termination and excitation of these structures. The signal-to-noise ratio and noise figure of CROW amplifiers are derived in the tight-binding formalism as well. The physical interpretations and practical consequences of the theoretical results are discussed.
© 2007 Optical Society of America
Original Manuscript: May 10, 2007
Manuscript Accepted: June 4, 2007
Published: August 24, 2007
Joyce K. S. Poon and Amnon Yariv, "Active coupled-resonator optical waveguides. I. Gain enhancement and noise," J. Opt. Soc. Am. B 24, 2378-2388 (2007)