Taught herein is an integragted narrow bandpass filter array and a method of its fabrication. The filter array is a Fabry-Perot type of filter array, wherein the pass band changes with the thickness of the spacer layer. The integrated filter array comprises a substrate, a lower mirror stack, a spacer array, and an upper mirror stack. The spacer array is an array of varied thicknesses formed using a combinatorial deposition technique. The spacer array is used to control the pass band of each mini-size narrow bandpass filter and realizes the integration of narrow bandpass filters with different pass bands on a single substrate. The merit of this technique lies in its fabrication efficiency and finished product rate which are much higher than for conventional methods. The filter array is completely matched with detector arrays and functional in most of the important optical ranges.