Ultracompact Fully Integrated MegaPixel MultiSpectral Imager

Multispectral imaging or imaging spectroscopy obtains spectral content of an object by dividing the image data, pixel by pixel, into wavelength (color) bands. The resulting 3D data cube (x, y, λ) allows materials to be identified by their pixel spectral content at multiple wavelengths in addition to their spatial characteristics. A new class of multispectral imaging systems are being developed that utilizes lithographically patterned dichroic filter arrays integrated with standard CCD and CMOS detector arrays. These new imagers offer the unique advantage of scalability to tens of Megapixel resolutions, compact size, and no moving parts. Our multispectral imagers are much simpler to manufacture in volume because the complexity is in the lithographically patterned dichroics rather than in the bulk optical system. The patterned dichroic filter arrays are fabricated utilizing standard microlithography techniques and can incorporate up to 10 different wavelength bands deposited onto a single substrate. Each channel is selectively patterned on the substrate with the dichroic filter coating applied using standard thin film coating techniques. The technique is repeated for all of the wavelength bands and then the final filter array is directly attached and aligned onto the CCD.