Patent ID: 7907340

Claim:
A filter array comprising a plurality of narrow bandpass filters and integrated on a single substrate ( 1 ), each said narrow bandpass filter independently comprising a material having a structure of formula (LH) m xL(HL) m , wherein (LH) m represents a lower mirror stack; (HL) m represents an upper mirror stack; xL represents a spacer layer; H is a high refractive index layer; L is a low refractive index layer; m is the number of high and low refractive index layer pairs, m≧2; the optical thickness (nd) of said high refractive index layer is λ 0 /4; the optical thickness (nd) of said low refractive index layer is λ 0 /4; λ 0 is the design wavelength of the initial filter structure; and x represents a thickness coefficient, said thickness coefficient being the thickness of the spacer layer (i) divided by the thickness of said high refractive index layer, or (ii) divided by the thickness of said low refractive index layer; wherein each said lower mirror stack is directly deposited on and directly contacts said single substrate; wherein spacer layers of two adjacent narrow band pass filters directly contact one another; wherein lower mirror stacks of two adjacent narrow band pass filters directly contact one another; and wherein upper stacks of two adjacent narrow band pass filters directly contact one another; and wherein spacer layers of two adjacent narrow band pass filters have different thickness with respect to one another; wherein lower mirror stacks of two adjacent narrow band pass filters have the same thickness with respect to one another; and wherein upper stacks of two adjacent narrow band pass filters have the same thickness with respect to one another.