| Photonic crystals and photonic quasi-crystals as novel materials have the potential to stimulate the development of optical systems in the 21 st century. Similar to electrons, which have a band gap over a range of frequencies in the semiconductors, photons also have a band gap over a region of optical frequencies in photonic crystals.; Self-organization of colloidal photonic crystals as a fast and simple fabrication method has been widely used and researched in microelectronics and optics. However, the presence of defects such as array shift and vacant sites in colloidal micro-spheres results in disorder and reduction of the band gap in photonic crystals. This thesis investigates the use of laser tweezers to manipulate micron-size polystyrene colloidal particles. In order to control the 2D monolayer photonic crystals and quasi-crystals during the self-organization process, laser tweezers are used to minimize defects and pattern to templates. The average defect density can be reduced from 0.0047 mu m-2 to 0.0022 mum -2 for 2D photonic crystals. And the average defect density can be obtained as low as 0.00060 mum-2 for colloidal quasi-crystals. In this thesis, laser tweezers are investigated to determine whether this instrument can be used to control the organization of colloidal polystyrene particles in 2D arrays and on surface layer templates. The colloidal modeling systems set up in this thesis using laser tweezers provide a useful tool in both the study of colloidal crystallization and the processing of new structures in optics and microelectronics. |
