Superimposed detector arrays having optical filters

Claim 1

An infrared detector array simultaneously having two separate spectral responses, for communicating signals representative of infrared radiation detected in two separate ranges of wavelengths to processing circuitry, the array comprising: (a) a common substrate having first and second substantially parallel planar surfaces; (b) at least one filter element disposed upon at least one of said first and second planar surfaces of said substrate for attenuating infrared radiation outside the second range of wavelengths prior to its being sensed by said second detector elements; (c) a plurality of first detector elements disposed generally adjacent the first planar surface of said common substrate for detecting infrared radiation in a first range of wavelengths, said first detectors being formed upon one of said at least one filter element and said substrate; and (d) a plurality of second detector elements, the number of second detector elements substantially conforming to the number of first detector elements, the second detector elements disposed generally adjacent the second planar surface of said common substrate for detecting radiation in a second range of wavelengths, said second detectors being formed upon one of said filter element and said common substrate, said second detector elements receiving infrared radiation after the infrared radiation has passed through said first detectors and said common substrate; (e) wherein said at least one filter element comprises an interference filter having at least one aperture formed therein, said interference filter formed intermediate said first detector elements and said second detector elements, the aperture providing an opening from said common substrate to the upper surface of said interference filter; (f) wherein a single crystalline layer is graphotaxially grown from said common substrate through the aperture in each said interference filter and across the surface of each said interference filter, said single crystalline layer suitable for the formation of detector elements; and (g) wherein signals representative of the infrared radiation detected by the first detector elements is communicated to processing circuitry and signals representative of the infrared radiation detected by the second detector elements is also communicated to processing circuitry.

Claim 7

A method for forming an infrared detector array, the infrared detector array simultaneously having two separate spectral responses, the infrared detector array capable of communicating signals representative of infrared radiation detected in two separate ranges of wavelengths to processing circuitry, the method comprising: (a) forming a plurality of first detector elements upon a first planar surface of a common substrate for detecting infrared radiation in a first range of wavelengths, the first detector elements being comprised of a photosensitive material which is more sensitive to infrared radiation in the first range of wavelengths than in a second range of wavelengths; (b) forming a plurality of second detector elements upon a second planar surface of the common substrate for detecting infrared radiation in the second range of wavelengths, the number of second detector elements substantially conforming to the number of first detector elements, the second planar surface of the common substrate being generally parallel to the first planar surface of the common substrate, the second detector elements being comprised of a photosensitive material which is more sensitive to infrared radiation in the second range of wavelengths; and (c) forming at least one filter intermediate the first and second detector elements for attenuating infrared radiation outside of the second range of wavelengths; (d) wherein the step of forming at least one filter intermediate the first and second detector elements comprises forming at least one interference filter upon the common substrate intermediate the first detector elements and the second detector elements, each interference filter having at least one aperture formed therein, the aperture providing an opening from said common substrate to the surface of the interference filter not contacting the common substrate; and (e) wherein the step of forming at least one filter intermediate the first and second detector elements further comprises the step of graphotaxially growing a single crystalline layer from said common substrate, through the aperture in said each interference filter and across the surface of said each interference filter, the single crystalline layer being suitable for the formation of detector elements.

Claim 8

A method for forming an infrared detector array, the infrared detector array simultaneously having two separate spectral responses, the infrared detector array capable of communicating signals representative of infrared radiation detected in two separate ranges of wavelengths to processing circuitry, the method comprising: (a) forming a plurality of first detector elements upon a first planar surface of a common substrate for detecting infrared radiation in a first range of wavelengths, the first detector elements being comprised of a photosensitive material which is more sensitive to infrared radiation in the first range of wavelengths than in a second range of wavelengths; (b) forming a plurality of second detector elements upon a second planar surface of the common substrate for detecting infrared radiation in the second range of wavelengths, the number of second detector elements substantially conforming to the number of first detector elements, the second planar surface of the common substrate being generally parallel to the first planar surface of the common substrate, the second detector elements being comprised of a photosensitive material which is more sensitive to infrared radiation in the second range of wavelengths; and (c) forming at least one filter intermediate the first and second detector elements for attenuating infrared radiation outside of the second range of wavelengths; (d) wherein the step of forming at least one filter intermediate the first and second detector elements comprises forming at least one interference filter upon the common substrate intermediate the first detector elements and the second detector elements, each interference filter having at least one aperture formed therein, the aperture providing an opening from said common substrate to the surface of the interference filter not contacting the common substrate; and (e) wherein the step of forming at least one filter intermediate the first and second detector elements further comprises the step of graphotaxially growing a single crystalline layer from said common substrate, through the aperture in said each interference filter and across the surface of said each interference filter, the single crystalline layer being suitable for the formation of detector elements.