Ultrathin BBO Crystals

Ultrathin BBO Crystals

BBO crystal is by far the most useful nonlinear crystal for frequency conversions of ultrafast lasers. One of the main considerations for ultrafast applications is pulse broadening induced by the group velocity (V_g) mismatch between the input pulses and the generated pulse due to the dispersion in the crystal. In order to avoid pulse broadening, the thickness of the crystal should not exceed the maximum length L_max as defined by the pulse width divided by the inversed group velocity mismatch (IGVM = ΔVg^-1). In the table below are the L_max for second harmonic generation (SHG) and sum frequency generation (SFG) of 10 fs pulses in the wavelength range of a common Ti:Sapphire laser,   
 

A thickness of sub-100 µm (0.1 mm) is apparently desired for all the frequency conversion processes of 10 fs pulses. In particular, crystals as thin as 10-20 µm may be needed for generation of very short UV wavelengths below 300 nm.  

Newlight Photonics offers on this page ultrathin/thin BBO crystals 10 µm (0.01 mm) - 3.0 mm thick developed for frequency conversions of short pulses. The typical apertures are 5x5 mm, 6x6 mm, 10x10 mm, 12x12 mm, and 15x15 mm.

We also supply birefringent calcite plates and alpha-BBO plates for compensation of the temporal walkoff in BBO crystals (time delay compensators).

For thicker BBO crystals (T>3 mm) for longer pulses (ns, ps), please visit  Thick BBO Crystals.