Ultra-broadband second-harmonic generation using spectral angular dispersion in quasi-phase-matched nonlinear materials

摘要

We demonstrate the use of spectral angular dispersion in quasi-phase-matched second-harmonic generation (SHG) of 138 fs pulse at 1550 nm in a 1-cm-long crystal of periodically-poled lithium niobate (collinear acceptance bandwidth 13 times narrower than the first-harmonic bandwidth) with minimal spectral narrowing. In addition, we discuss the unique potential of quasi-phase-matched nonlinear materials in noncollinear SHG, and compare this technique to other methods for broadband frequency conversion.