Super-octave longwave mid-infrared coherent transients produced by optical rectification of few-cycle 2.5-μm pulses

Academic Article

Abstract

  • Femtosecond laser sources and optical frequency combs in the molecular fingerprint region of the electromagnetic spectrum are crucial for a plethora of applications in natural and life sciences. Here we introduce Cr 2 -based lasers as a convenient means for producing super-octave mid-IR electromagnetic transients via optical rectification (or intra-pulse difference frequency generation, IDFG). We demonstrate that a relatively long, 2.5 μm, central wavelength of a few-cycle Cr 2 :ZnS driving source (20 fs pulse duration, 6 W average power, 78 MHz repetition rate) enabled the use of highly nonlinear ZnGeP 2 crystal for IDFG with exceptionally high conversion efficiency (>3%) and output power of 0.15 W, with the spectral span of 5.8–12.5 μm. Even broader spectrum was achieved in GaSe crystal: 4.3–16.6 μm for type I and 5.8–17.6 μm for type II phase matching. The results highlight the potential of this architecture for ultrafast spectroscopy and generation of broad-band frequency combs in the longwave infrared.
  • Authors

    Published In

  • Optica  Journal
  • Digital Object Identifier (doi)

    Author List

  • Vasilyev S; Moskalev IS; Smolski VO; Peppers JM; Mirov M; Muraviev AV; Zawilski K; Schunemann PG; Mirov SB; Vodopyanov KL
  • Start Page

  • 111
  • End Page

  • 114
  • Volume

  • 6
  • Issue

  • 1