Single crystal growth and characterization of a new organic nonlinear optical material: 8-(4'-acetylphenyl)-1,4-dioxa-8-azaspiro[4.5]decane (APDA)

Abstract

8-(4'-Acetylphenyl)-1,4-dioxa-8-azaspiro[4.5]decane (APDA) was found to be a new organic material for nonlinear optical devices. Prior to its application to devices, material purification, single crystal growth, characterization and optical properties were studied, and second harmonic generation from the grown single crystal was demonstrated. Recrystallization from ethyl acetate solution by slow cooling, zone refining and sublimation under reduced pressure were explored. Among them, a combination of recrystallization and sublimation was the most effective for APDA purification. Single crystals were grown by the Bridgman technique with different growth parameters for the furnace temperature, the growing rate and the cooling rate of grown crystals. Single crystals with a diameter larger than 12 mm and length of 28 mm were obtained from the melt, but had some cracks. Characterization, measurements of optical properties of APDA crystals and second harmonic generation demonstration revealed that the crystals had good quality suitable for application to nonlinear optical devices, for example, frequency doublers of laser diodes in the blue region.