| || Concentric Arrays of Ring Shaped Apertures as Neutral Density Filters
Author : Kumar, Surendra
Source : Defence Science Journal ; Vol:15(3) ; 1965 ; pp 165-168
Subject : 535 Optics
Keywords : Curves ;Neutral Filter
Abstract : Neutral density filters with flat transmission curves find extensive use in optical instruments, but really neutral filters i.e., with flat transmission are rather difficult to fabricate. A new method of making neutral filter has been discussed here from the oretical as well as practical aspect.