| 摘要 |
PROBLEM TO BE SOLVED: To provide a design method of a Lyot filter that has excellent convenience, efficiency and general applicability. SOLUTION: This method makes design of the Lyot filter possible by deciding the central wavelength and other necessary parameters using a graph. Using a plotted figure in which conditions that the transmissivity of a birefringent filter indicates a maximum value for each order and conditions for each half value width of the central wavelength are preliminarily plotted as a graph, the central wavelength of the Lyot filter to be designed and its half value width are decided (S1). Then, the decided central wavelength is shown as a graph in the plotted figure, the intersection is determined between this graph and a graph showing conditions relative to the decided half value width in the plotted figure (S2). Thus, by the normal drawn from the intersection to an optical path difference axis, the optical path difference to be used for the Lyot filter is determined among the optical path difference values taking a value m times or (m+1/2) times (m is an integer) as large as the central wavelength (S3). COPYRIGHT: (C)2005,JPO&NCIPI
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