Engineered quasiphasematched crystals for second-harmonic generation

The ability to engineer nonlinear crystal phasematching properties promises practical benefits in a variety of situations and systems and frequency-response engineering should enable the conversion efficiency of nonlinear crystals to be flattened across a wide bandwidth, making it possible(for example) to achieve uniform conversion and avoid gain-narrowing in optical parametric amplifiers. In this paper we present a procedure for determining the quasiphasematched grating design necessary to achieve any desired spectral conversion response.