GROWTH AND PLANAR STRUCTURING OF DAST CRYSTALS FOR OPTICAL APPLICATIONS

The organic salt 4-N, N-dimethylamino-4′-N′-methyl stilbazolium tosylate (DAST) is a nonlinear optical crystal with superior properties for integrated electro-optical applications and THz-devices. High quality DAST single crystals have been grown by the solution growth method. The electro-optical properties were determined in the spectral range between 700 and 1535 nm (r111=47±8 pm / V at λ=1535 nm ). Several planar structuring techniques for integrated optics applications based on DAST have been investigated. The production of single crystal thin films with minimal thicknesses of 10 μm is presented as well as the channel waveguide structuring of DAST surfaces by photobleaching techniques in the depth range of 0.2 up to 2.6 μm and by femtosecond laser ablation.