| 摘要 |
<p>An improved optical system is disclosed for rapid, accurate spectral analysis of the reflectivity or transmissivity of samples. A grating oscillated at high speed is utilized to provide a rapid scanning of monochromatic light through a spectrum of wavelengths. The grating is positively driven at very high speed. The rapid scan by the grating enables the reduction of noise error by averaging over a large number of cycles. It also reduces the measurement time and thus prevents sample heating by exessive exposure to light energy. Source optics is employed to project light radiation on the grating. An exit slit receives light dispersed by the grating as the grating oscillates and a cylindrical lens in the path of light passing through the exit slit produces a virtual image of the width of the exit slit on the grating. Optical means are provided to focus from the radiation passing through the cylindrical lens a real image of the composite of the virtual image of the width of the exit slit at the grating and the height of the grating and to project the radiation the sample. Photosensing means are provided for detecting radiation from the sample.</p> |
