ABSTRACT:In this paper, an improved design of a tunable optical filter device made up of alternating layers of MgF 2 and Ta 2 O 5 is proposed. Different configurations of this narrow band pass (NBP) optical filter are used for whole visible spectral range (400nm-700nm).We report on the calculated values of the design parameters, such as pass band wavelength, 3-dB bandwidth and quality factor for different configurations of narrow band pass optical filter. The design parameters are also evaluated when varying the angle at which the optical wave is incident on the input layer of the filter