| 摘要 |
The multispectral imaging device comprises a structure having multi-quantum wells operating on intersubband transitions by absorption of radiation at a lambda wavelength comprised in a set of wavelengths to which the structure is sensitive. The structure comprises a matrix (Eij) of elementary pixels for detection, where the matrix is organized into subsets of four elementary pixels for detection. A first elementary pixel for detection (P(lambda 1)) comprises a first diffractive network (R(lambda 1)) sensitive to a first subset of wavelengths. The multispectral imaging device comprises a structure having multi-quantum wells operating on intersubband transitions by absorption of radiation at a lambda wavelength comprised in a set of wavelengths to which the structure is sensitive. The structure comprises a matrix (Eij) of elementary pixels for detection, where the matrix is organized into subsets of four elementary pixels for detection. A first elementary pixel for detection (P(lambda 1)) comprises a first diffractive network (R(lambda 1)) sensitive to a first subset of wavelengths. A second elementary pixel for detection (P(lambda 2)) comprises a second diffraction network (R(lambda 2)) sensitive to a second subset of wavelengths. A third elementary pixel (P(lambda 3)) comprises a third diffraction network (R(lambda 3)) responsive to a third subset of wavelengths. A fourth elementary pixel comprises a structure for optical coupling non-selective in wavelength. A unit is arranged for processing signals recovered at the elementary pixels for detection, and comprises a unit for adding the signals obtained from the first, second and third elementary pixels for detection and a unit for subtracting the signal obtained from the fourth elementary pixel for detection. The first, second and third diffraction networks are one-dimensional networks comprising lamellar patterns. A stack of layers is produced on the surface of a substrate with multi-quantum wells and outer layers. The periodic patterns are engraved in an outer layer to produce different networks. The structure having multiple quantum wells comprises a set of sub-structures of variable stacks of semiconductor layers to make the structure sensitive to a range of wavelengths. The stack of layers is doped with gallium arsenide or indium gallium arsenide, and is constituted of barriers. The external layers of ohmic contact layers made of gallium arsenide are more strongly doped than those constituting the structure having multi-quantum wells. A transparent substrate is present at a wavelength of incident radiation. A reflective layer is present on the surface of diffraction network to operate the detector by reflection. A micro-scanning unit is arranged for making a series of images containing different spectral information. |
