| 摘要 |
PURPOSE:To obtain an optical filter that intercepts suddenly the light having a wavelength shorter than the specific wavelength, by forming a light absorbing film on a supporter by laminating multiple semiconductor thin film layers having different compositions so that the composition varies periodically in the width direction. CONSTITUTION:Plural multiple semiconductor thin films (such as PbTe layer 2 plus Pb0.8Sn0.2Te layer) having different compositions are laminated alternately by the hot wall epitaxial method on the main surface of a single side of a supporter 1 made of an infrared ray transmitting material (BaF2, etc.). Thus a multiple layer 3 is formed to obtain an optical filter that has the sudden intercepting characteristics and an absorbing end varying optionally within a certain range. |
