Fabrication of crystalline organic waveguides with an exceptionally large electro-optic coefficient

Single-crystal optical waveguides of 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST), an organic material with a large electro-optic coefficient, have been obtained. DAST decomposes at its melting temperature, making its growth from the melt difficult. However, graphoepitaxy allows for >1 mm s(-1) growth, 1x10(5) times faster than conventional techniques, and produces crystals of the correct dimensions for optical waveguides, 1-15 mum on a side and 5-10 mm long. The crystals grow with the c-axis normal to the substrate, and with in-plane orientation determined by lithographic patterning. The electro-optic coefficient dn/dE is 600+/-300 pm V-1 at 1.55 mum wavelength. Optical losses are <10 dB cm(-1). (C) 2004 American Institute of Physics.