Coherent control and dark pulses in second harmonic generation

✍ Scribed by Paweł Wnuk; Czesław Radzewicz

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 250 KB
• Volume: 272
• Category: Article
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2006.11.054

✦ Synopsis

We present the results of our study of the second harmonic generation (SHG) in a nonlinear crystal using phase modulated femtosecond laser pulses. We show experimentally that the SHG process is an analogue of two photon absorption (TPA), yet it provides a better way to study coherent control because it enables one easier control of some important parameters. We demonstrate that for a thick nonlinear crystal pure phase manipulation can result in nontrivial pulses maximizing the second harmonic conversion efficiency and in dark pulses which are not converted at all. With a p step phase modulation applied to the pulse we have measured conversion efficiency for a set of crystals with different thicknesses to explore the effect of a finite spectral width of the TPA transition.