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Circular Variable Filter

A circular variable filter is an interference filter, where the thickness of the interference layer varies along an arc. For the CVF implemented in SHARP II+, the intrinsic resolution -- the area of the CVF used to measure the transmission curve is small compared to a resolution element and the beam divergence is negligible -- and its transmission are listed in table 2.4 for 3 wavelengths.

Table 2.4:   Intrinsic Resolution and transmission of the CVF

Because the transmitted area of the CVF within the SHARP II+ camera is of finite size, the achieved spectral resolution (summarized in table 2.5) is somewhat smaller than the intrinsic resolution.

Table 2.5:   Resolution of the CVF in SHARP II+

Frank Eisenhauer
Wed Apr 23 16:00:15 MDT 1997