We present experimental observations and corresponding numerical simulations illustrating the difference-frequency generation of mid-infrared radiation using few-cycle near-infrared-to-visible pulses, which yields conversion efficiencies above 12% in beta-barium borate crystal. Type I and type II phase-matching are shown to yield qualitatively different intensity-scaling behavior, with the former showing higher overall efficiency, especially with the addition of a zero-order wave plate for modifying the polarization state of the pulse, and the latter having a better stability of the spectrum versus input intensity.
© 2013 Optical Society of America
Original Manuscript: August 21, 2013
Revised Manuscript: September 17, 2013
Manuscript Accepted: September 18, 2013
Published: October 14, 2013
Hanieh Fattahi, Alexander Schwarz, Sabine Keiber, and Nicholas Karpowicz, "Efficient, octave-spanning difference-frequency generation using few-cycle pulses in simple collinear geometry," Opt. Lett. 38, 4216-4219 (2013)