Femtosecond continuum generation in bulk laser host materials with sub-micro-J pump pulses
Applied Physics B, 2009, 97, 561-574 published on 21.09.2009
Applied Physics B
We report a comprehensive investigation of femtosecond continuum generation in single crystals of several common laser host materials. The absolute spectral energy density, pulse-to-pulse stability, pump threshold and beam profile are studied in dependence on the focusing conditions, crystal thickness, pump pulse energy and pump wavelength (775-1600 nm). Continuum generation is shown at repetition rates of up to 80 MHz and for pump pulse durations of up to 350 fs. In yttrium aluminum garnet (YAG), yttrium vanadate (YVO4), gadolinium vanadate (GdVO4) and potassium-gadolinium tungstate (KGW) thresholds below 50 nJ, plateau-like visible and infrared spectra, and higher infrared photon flux as compared to conventional materials like sapphire are found. We discuss the particular advantages of these materials for application in parametric amplification, femtosecond spectroscopy and carrier-envelope phase stabilization.