Near Field Optical Technology for High Density Optical Storage and Nano-photonics

Near-field optical excitation with apertured optical fiber has been utilized to realize the high density data storage with spot sizes beyond the diffraction limit. So far, magneto-optical-mode storage on a Co/Pt film [1] and optical-mode one on the LB film of amphiphilic azobenzene derivative [2] have been reported. Recently, with regard to the latter technique, much smaller pit sizes are successfully achieved by using a nanometric aperture. In order to increase the write speed, high excitation density through the aperture is required. For this purpose, we optimize the shape of fiber probe for attaining high transmission efficiency of light. Its ability in the application to nano-photonic devices is also demonstrated through the spatially resolved spectroscopy of novel-structured semiconductor devices.