Morphology and lightguide property investigation of a high quality DAST single crystal

A high quality 4′-dimethylamino-N-methyl-4-stilbazolium tosylate single crystal with dimension of 7×7×1 mm3 was grown in this study. The polarized optic microscopy photograph showed that the surface of this crystal was ordered and flat. Three-dimensional luminance image analysis demonstrated that the intensity of a guided laser light passing through the single crystal along its molecular structure alignment is stronger than that guided along a standard 8.5/125 μm silica optic fiber. The diameter of the guided light and the space between the two guided lights through the single crystal were estimated at around 25 and 65 μm, respectively. The FTIR spectrum implied that the single crystal is more suitable for use as a communication window than the disordered polycrystalline samples. The result reveals that without further processing the single crystal can be used as a waveguide and is a promising candidate for electro-optic modulators and other active optical devices.