In situ shaping of phase-matching profiles using the electro-optic effect in segmented QPM crystals

Summary form only given. The spectral shape of quasi-phase-matching (QPM) profiles of poled crystals can be designed to control the duration of ultra-short pulses or to optimize multi-channel wavelength conversion. After a crystal is manufactured, however, the shape of the phase-matching profile is fixed, and no in situ optimization is possible. Here we present a novel method, which allows one to change the phase-matching spectra of QPM crystals in situ, i.e., during operation of the crystal. To demonstrate the method we experimentally investigate single-pass second harmonic generation (SHG) and optical parametric oscillation (OPO). These crystals offer a high potential for an on-line adjustment of multi-channel frequency conversion, and for an on-line adjustment of pulse shapes, if extended to a larger number of alternating electro-optic and QPM segments.