Subharmonic Generation of Tunable Ti:Sapphire Laser

Abstract

As it was mentioned in the papers [1,2] the Ti:Sapphire and Cr:Forsterite tunable lasers can be used as basic sources for getting tunable coherent radiation in the spectral range 0,2–5,5 μm and even wider. The central part of this range 0,68–1,37 μm is covered by the main frequency generation of Ti:Sapphire and Cr:Forsterite lasers. The short-wavelength is covered by harmonic generation of the new nonlinear crystals, such as BBO, LBO, KTP [3 – 5]. The long-wavelength part of the above mentioned range was gained by the differece frequency generation of tunable lasers (in the dual-wavelength regime) or tunable and pump lasers. In this case the main problem is the synchronization of pulses to be mixed. Different methods were used for this problem solution [6,7]. Besides the synchronization difficulty, this method has a principal deficiency - energetic efficiency limit at a given wavelength. In this proces the long-wavelength is loosing and the energetic efficiency is less than one. The middle and far IR generation efficiency is especially noneffective. In this case the long-wavelength quantum energy (hv _l) is comparable with short-wavelength quantum hv _s .