Novel Nonlinear and Photosensitive Materials for Advanced Photonic Switching Devices

(Faculty Mentor: I. C. Khoo)

 

This research program will focus on materials for optical sources, sensors and limiters that will enable the development of next and future generation devices and systems. Students will be given tutorials on advanced optical materials, and go through some hands on experiment with short pulse (picosecond) lasers, as well as material/sample synthesis. Among the materials to be studied are photonic crystals formed by self-assembly or nano-fabrication techniques, and liquid crystals which also exhibit self-assembly and order. Upon completion of the summer study, students will acquire valuable understanding of these novel optical materials, an appreciation of how research are conducted, and some hands-on experience with lasers and other advanced instrumentation.

 

       Our research program will be centered on two particularly noteworthy nonlinear optical phenomena observed in the nematic and isotropic phases of liquid crystals. Both are based on the fact that the properties of such organic systems can be modified with the aid of engineering at the molecular level, as well as by using LC as a host/guest medium in conjunction with ordered or random nanostructures. In nematic liquid crystals containing photo-charge producing agents, for examples, laser induced director axis reorientation and order parameter changes give rise to a refractive index change coefficient that is orders of magnitude larger than all known nonlinear optical materials. Such supra-nonlinear materials open a whole new field of research and development opportunities in advanced next generation opto-electronics devices of unprecedented low operation thresholds. Based on this and recent development of reconfigurable nano-particle network, a new class of so-called nano-dispersed supra-nonlinear liquid crystalline material system have emerged as a highly promisingly material for research and development. By dispersing such supra-nonlinear liquid crystal in nanoparticle networks, one could anticipate even more dramatic and revolutionary performance characteristics. These supra-nonlinear liquid crystalline material system will push the operation characteristics of these optoelectronic devices to unprecedented laser power regime [microWatt to nanoWatt], spectral bandwidth [visible - IR] and temporal [dynamic - storage mode].