Generation of SHG Holograms at 400 nm from a Beam-Shaped Fundamental Using Short Femtosecond Pulses in a Collinear Type-2 Phase Matching Crystal

The feasibility of using beam shaped short femtosecond pulses in combination with a nonlinear frequency conversion process to create any arbitrary beam shape in the ultraviolet spectrum is shown.Broadband femtosecond pulses (800 nm centre, 30 nm Bandwidth FWHM, 50 fs) are shaped via a spatial light modulator (SLM) and converted to 400 nm in a subsequent second harmonic process to 400 nm in a collinear setup while conserving the beam shape information by using orthogonal polarisation states to avoid beam shape degradation.Additionally, it is shown, that the holograms exhibit blurred edges due to chromatic dispersion stemming from the bandwidth of the utilized fs pulses and the conversion efficiency is linked to the angular spectrum created at the SLM.