| 摘要 |
PURPOSE:To simultaneously reproduce plural information signals by forming in a thin film shape the focusing grating coupler (FGC) and the light detecting system, obtaining the multi-layer structure, providing the grating coupler (GC) and forming plural fine spots on the disk surface. CONSTITUTION:The laser light to emit from a semiconductor laser 1 is refracted by GC 2a formed at the upper layer waveguide 5a and divided into the upper layer waveguide 5a and an upper layer substrate 9a. The light made into the parallel by thin film focusing lenses 3a and 3b transmits thin film beam splitters 3a and 3b respectively, further, propagates thin film waveguides 5a and 5b and two spots are formed on a disk 7 by FGC 5a and 5b. The spot on the disk 7 can be made into the fine spot with the diameter of about 1mum respectively and the recording density of the disk 7 is enlarged. Next, the light reflected from the disk 7 is made incident on FGC 6a and 6b respectively again, refracted, focused by thin film focusing lenses 3c and 3d, and thereafter, the light is made incident on detecting devices 8a and 8b. |
