Optical parametric amplifiers using chirped quasi-phase-matching gratings I: practical design formulas

Optical parametric amplifiers using chirped quasi-phase-matching (QPM) gratings offer the possibility of engineering the gain and group delay spectra. We give practical formulas for the design of such amplifiers. We consider linearly chirped QPM gratings providing constant gain over a broad bandwidth, sinusoidally modulated profiles for selective frequency amplification and a pair of QPM gratings working in tandem to ensure constant gain and constant group delay at the same time across the spectrum. The analysis is carried out in the frequency domain using Wentzel-Kramers-Brillouin analysis. (C) 2008 Optical Society of America.