抄録
A new method to make an optical diffractional grating was already reported. A periodical magnetic pattern is written in a magnetic memory medium, and a magnetic fluid is used as magnetic toner to visualize this pattern. Using this method, an optical grating can easily be formed even on a convex or concave surface. As an optical characteristic of this relief type grating is decided by a cross sectional shape, it is important to investigate this cross sectional shape for application to an encoder plate or an optical component. When the grating constant bacomes small, positions depositing magnetic fluid are changing from domain walls to magnetic domains. By analyzing the Fraunhofer diffraction pattern of the grating, the relationship between a cross sectional shape and developing conditions was investigated. According to the results, the shape is sinusoidal- or circular-arc when the grating constant is less than 10μm.
