Tunable-chirp pulse compression in quasi-phase-matched second-harmonic generation

We demonstrate continuously tunable compensation of linear chirp on a first-harmonic pump pulse to produce a near-transform-limited second-harmonic output pulse through the use of a chirped, fanned, periodically poled lithium niobate quasi-phase-matching grating. Compensation of positive and negative chirps is possible through reversal of device orientation. The device is simple and monolithic and can be applied to compensation of a higher-order phase with minor modification.