Executive Summary : | This project is aimed to optimize the growth parameters of piperazine derivative materials to get high quality and large-size (100 mm in length and 25 mm diameter) single crystals for obtaining second harmonic generation (SHG) device elements with high laser damage threshold (LDT). Conventional solution growth method has the limitation that the crystal grows in its natural morphology with several habit faces. When the SHG element is obtained from the conventional method grown crystal, substantial amount of the crystal goes waste in cutting along its phase matching (PM) directions. Due to this drawback in the conventional solution growth method, it is intended to grow the crystals using the Sankaranarayanan-Ramasamy (SR) method which allows to grow the crystals along its preferred direction. Efforts can be made to grow the crystals along their phase matching direction, so that the wastage of crystal in obtaining large size SHG element can be minimized. It is required to grow the crystals by optimizing the crystal growth method to develop a high quality crystal for device applications. In the present proposed new method, the point seed rotation technique will be applied in SR method to grow the high quality and large size single crystals for SHG device applications. This new method may be named as "Rotational Sankaranarayanan-Ramasamy (RSR)" method. From this new RSR method it is expected to grow several technologically important single crystals with better physical properties (like higher optical transmittance, higher mechanical stability, higher laser damage threshold, higher dielectric properties, good optical homogeneity and so on) and higher crystalline perfection compared to the slow evaporation solution technique (SEST), slow cooling method, seed rotation technique, point seeded crystal growth method and slotted ampoule SR method grown crystals. This new method will be introduced for the development of high quality, SHG oriented and large size piperazine derivative single crystals, which will be helpful to avoid the problem of impurity segregation. The physical properties such as optical transmittance, mechanical stability, laser damage threshold (LDT) property, thermal stability, optical homogeneity, electrical property and crystalline perfection of the piperazine derivative single crystals will be investigated. Suitable dopants will be tried to explore the possibilities of enhancing the growth rate along the phase matching direction and also to increase the SHG efficiency. SHG element will be made out of the grown piperazine derivative single crystals and characterized by measuring the SHG efficiency. |