Super parallel near-field optical head with possibility of ultrahigh data rate - ultrahigh density optical disk system using VCSEL array

摘要

In order to meet the requirement for an ultrahigh data transfer rate in future optical communication systems, the parallel optical memory system has been developed using a VCSFL array and three-dimensional microoptical here (VCSFL array and Microlens array of which focal points self-aliened on the top tip of the Nano-Probe array) and self-adjustment. The concept, theoretical analysis and fabrication process for the array head are discussed with emphasis on the microoptical issues such as the improvement of optical efficiency with by microlens focusing. The flat-tip microprobe structure was successfully prepared with the small metal aperture of 150 nm and 1.25% optical throughput using metal-aperture Si or GaP semiconductor microprobes. From the FDTD simulation, the optical throughput can be improved using a buried-type microprobe with an asymmetric metal-coated structure since this is a better structure for the coupling efficiency between the propagating wave and surface plasmon. Since the focused beam is helpful for the better optical throughput in the integrated VCSFL microprobe array, the microlens array is developed on the other side of microprobe array using the thermal reflow of photoresist and the pattern transfer process to the semiconductor substrate. The alignment of optical axis between the optical components is critical to get the required optical efficiency in this system. Thus, three-dimensional microoptical adjustment is being studied to focus very small spot on the recording media. This three dimensional approach will give a guideline to new micro-optical components in the future technology in the field of the optical memory and other micro-optical systems.