| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical filter for wavelength bands of multiband (for example, a band of 3 to 5 μm and a band of 8 to 14 μm in infrared light), which is superior in long-term reliability even in a special environment like space, and an optical device using the same. <P>SOLUTION: A three-dimensional solid structure being a multiple structure in a sub-wavelength size sufficiently smaller than target wavelength bands is formed one or both of surfaces of the optical filter, whereby transmission characteristics of target wavelength bands of multiband are improved by stepwise changes of an effective refractive index. <P>COPYRIGHT: (C)2010,JPO&INPIT |
