| 摘要 |
PURPOSE:To reduce the number of components and attain cost-down while keeping the equal optical performance to that of a conventional device by dividing a photodetecting face of a photodetector into plural numbers, and selecting the width of a split slot <=7mum. CONSTITUTION:The photodetecting face of a photodetector 4 is split into plural numbers and the width of slot d1 of the split slots 7, 8 is selected to be <=7mum. As a result, the reflecting light radiated to the photodetecting face of the photodetector 4 is increased in the rate of radiation on split parts 9a-9d and it is possible to obtain a proper optical output without magnifying a spot by a magnification lens, for example. Thus, it is not required to provide the magnification lens, the number of components is increased, and the manufacturing cost is reduced. |
